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Appendix E7b
Biological Assessment for the I-405,
Tukwila to Renton Improvement
Project [I-5 to SR 169 - Phase 2]
(June 2007)
Washington State Department of Transportation
I-405/I-5 to SR 169 Stage 2 -
Widening and SR 515
Interchange Project
Request for Proposal
October 6, 2008
1
2
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4
5
6
7
8
9
Biological Assessment 10
For 11
I-405, Tukwila to Renton Improvement Project 12
(I-5 to SR 169 – Phase 2) 13
14
15
Sixth Field HUC Code 16
Lower Green River: 171100130399 17
Lower Cedar River: 171101120106 18
19
20
21
Urban Corridors Office 22
401 2nd Avenue South, Suite 400 23
Seattle, WA 98104-3850 24
25
26
27
28
Prepared by: 29
Washington State Department of Transportation 30
I-405 Project Team 31
32
33
34
35
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) i
Executive Summary 36
37
The I-405 Tukwila to Renton Improvement Project (Project) is a Washington State Department of 38
Transportation (WSDOT) project that results in improvements to the Interstate-405 (I-405) and State 39
Route 167 (SR 167) corridors in and around the cities of Renton and Tukwila, Washington. The 40
Project extends approximately 4 miles along I-405, from I-5 to SR 169, and approximately 2 miles 41
along SR 167, from I-405 to SW 43rd Street. It expands on the Renton Nickel Improvement Project, 42
which added one lane in both directions on I-405 between I-5 and SR 167 and between SR 167 and SR 43
169, extended the southbound high-occupancy vehicle (HOV) lane on SR 167 north to I-405, and 44
added one lane southbound on SR 167 between I-405 and SW 41st Street. The constructed Renton 45
Nickel Improvement Project is assumed to be the environmental baseline for the Project for the 46
purposes of this Biological Assessment (BA). 47
48
From I-5 to SR 181, the Project realigns the I-405 roadway near the Westfield Shoppingtown Mall to 49
accommodate improvements near the Green River and SR 181, constructs or modifies six bridges over 50
the Green River, lowers the Green River Trail, and realigns the Interurban Trail. At the I-405/SR 181 51
interchange, the Project reconstructs the south half of the interchange, including extending Tukwila 52
Parkway east to SR 181 over the Green River (one of the six previously mentioned bridges over the 53
Green River) and constructs a new on-ramp from Tukwila Parkway to northbound I-405, and improves 54
the north half of the interchange. 55
56
From SR 181 to SR 167, the Project constructs one additional lane in both directions on I-405. The 57
Project also reconstructs the I-405/SR 167 interchange, including constructing a general purpose 58
direct-connector ramp between southbound I-405 and southbound SR 167, a HOV direct-connector 59
that connects northbound SR 167 with northbound I-405 and southbound SR 167 with southbound I-60
405, and exterior ramps from northbound I-405 to and from SR 167. The Project also shifts local 61
access between Renton and I-405 from SR 167 to new ramps at Lind Avenue and SR 515 (Talbot 62
Road). This new split diamond interchange consists of half-diamond interchanges at Lind Ave and 63
SR 515 (Talbot Road) with one-way frontage roads between them. 64
65
From SR 167 to SR 169, the Project constructs two additional lanes in both directions on I-405. The 66
Project also constructs a new I-405 half diamond interchange at SR 515 that will be connected by one-67
way northbound and southbound frontage roads. Access between the City of Renton and I-405 shifts 68
to the Lind Avenue and SR 515 half diamond interchanges. Four bridges will be either replaced, 69
reconstructed, or relocated over the Cedar River; these bridges are northbound and southbound I-405, 70
the Burlington Northern Santa Fe (BNSF) Railroad, and a pedestrian bridge. 71
72
Along SR 167, the Project also constructs a northbound auxiliary lane from approximately SW 43rd 73
Street to I-405. The SR 167 mainline is reconstructed from about SW 23rd Street to I-405 for the 74
interchange improvements. 75
76
Improvements will also be made to local roads and the stormwater drainage system associated with the 77
Project. East Valley Road between SW 16th Street and SW 23rd Street will be reconstructed. Two 78
local street accesses to Renton Hill will be replaced. The Houser Way bridge will be removed and 79
traffic will be redirected to Bronson Way. The Project also includes new stormwater management 80
facilities and a substantial upgrade of existing drainage structures and systems. 81
82
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) ii
At present, the only portion of the Project that is funded is the I-405, SR 515 Interchange Project (SR 83
515 Project) that is slated for construction beginning in 2008 and ending in 2011. No other stages of 84
the Project have been funded to date. However, a second stage of the Project, the I-405, SR 167 High 85
Occupancy Vehicle Direct Connect Ramp Project (SR 167 HOV Ramp Project) may be constructed 86
should funding become available as a result of the November 2007 Regional Transportation 87
Investment District (RTID) vote. Future Project stages will be constructed as funding becomes 88
available. Mitigation for the individual Project stages will be performed concurrently with the 89
construction of a given Project stage, in accordance with applicable local, state, and federal permitting 90
requirements. 91
92
Mitigation will be provided to compensate for the loss of wetland and stream resources within the 93
Project area per requirements of the U.S. Army Corps of Engineers (Corps) Section 404 permit and the 94
Washington State Department of Fish and Wildlife (WDFW) Hydraulic Project Approval (HPA). 95
Wetland and floodplain mitigation for the Project is anticipated to occur at the Springbrook Creek 96
Wetland and Habitat Mitigation Bank (Springbrook Bank). No additional wetland mitigation will be 97
provided for the Project; however, additional floodplain mitigation will be provided as a result of 98
lowering the Green River Trail during construction of the new Tukwila Parkway bridge. A portion of 99
the stream and river mitigation for the Project will be implemented through the Panther Creek 100
Watershed Rehabilitation Plan (PCWRP). The PCWRP is an I-405 Water Resource Initiative that will 101
provide stream mitigation for the portion of the Project within the Panther Creek and lower 102
Springbrook Creek sub basins. The PCWRP is included in this BA as an element of the Project. 103
104
In addition to the PCWRP, additional mitigation activities are anticipated for Project impacts that will 105
occur in the Green and Cedar Rivers. Due to a lack of dedicated funding for the future phases of the 106
Project that would impact these rivers, specific mitigation activities for impacts to the Green and Cedar 107
Rivers have not been identified. Additional aquatic resources mitigation may occur on one or more 108
waterbodies in the vicinity of the Project footprint or at an off-site location. When implemented, all 109
mitigation activities for the Project will adhere to the requirements of the applicable local, state, and 110
federal permits obtained for the Project. These projected compensatory mitigation actions are 111
anticipated to offset negative effects from the Project. 112
113
It is anticipated that the Project will use the Design-Build model, in which WSDOT executes a single 114
contract with a Design-Build Contractor (Contractor) for final design and construction services to 115
provide a finished product. In this model, WSDOT defines the basic objectives of the Project and 116
develops outcome-based requirements to ensure that the Project is designed and constructed in 117
accordance with environmental regulations. The Contractor is then required to complete the Project in 118
accordance with the outcome-based requirements; however, specific details of design and construction 119
are up to the Contractor to complete. 120
121
This BA addresses impacts to Endangered Species Act (ESA) listed species that may occur in the 122
Project area including: bald eagle (Haliaeetus leucocephalus), bull trout (Salvelinus confluentus), 123
Puget Sound Chinook salmon (Chinook salmon; Oncorhynchus tshawytscha), and steelhead trout (O. 124
mykiss), all of which are listed as threatened under the ESA. It also addresses impacts to Chinook 125
salmon and bull trout critical habitat and Essential Fish Habitat (EFH) within the Project’s action area. 126
127
This BA does not address impacts to Canada lynx (Lynx canadensis), grizzly bear (Ursus arctos 128
horribilis), marbled murrelet (Brachyramphus marmoratus marmoratus), northern spotted owl (Strix 129
occidentalis caurina), or golden paintbrush (Castilleja levisecta), which are listed as threatened; marsh 130
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) iii
sandwort (Arenaria paludicola) or gray wolf (Canis lupus), which are listed as endangered; or fisher 131
(Martes pennanti), which is a candidate species, as these species do not occur in the action area and 132
because no suitable habitat for these species is located in the action area. 133
134
The Cedar and Green Rivers and Springbrook Creek are designated as critical habitat for Chinook 135
salmon (effective January 2, 2006). The Green River is also designated as critical habitat for bull trout 136
(effective October 26, 2005). 137
138
The primary potential direct and indirect effects on ESA listed species from this Project are from 139
construction-related activities including noise from construction, possible auguring of concrete piles or 140
impact pile driving, temporary sedimentation/turbidity from work in or around streams, dewatering and 141
removal (permanent and/or temporary) of riparian vegetation, and from placement of permanent 142
structures within waterbodies known or presumed to contain ESA listed species. In total, eight rivers 143
and streams (including both in-water and/or riparian buffer impacts) and 15 wetlands (including direct 144
and/or wetland buffer impacts) will be permanently impacted by the Project. The rivers and streams 145
that will be impacted either below the ordinary high water mark (OHWM) and/or within their riparian 146
buffers by the Project include Gilliam Creek, the Green River, Panther Creek, Rolling Hills Creek, an 147
unnamed tributary to Rolling Hills Creek, Thunder Hills Creek, an unnamed tributary to Thunder Hills 148
Creek, and the Cedar River. Of these rivers and streams, only Gilliam Creek, the Green River, Panther 149
Creek, and the Cedar River are known or presumed to contain ESA listed species. 150
151
The Effects Determinations from the Project on listed species and associated critical habitat are as 152
follows: 153
154
Species Status Agency
Effects
Determination
Critical
Habitat
Critical Habitat
Effects
Determination
Chinook salmon
(Oncorhynchus
tshawytscha)
Threatened
(Puget Sound
ESU)
NMFS
May Affect,
Likely to
Adversely Affect
Designated
May Affect,
Likely to
Adversely Affect
Steelhead trout
(Oncorhynchus mykiss)
Threatened
(Puget Sound
ESU)
NMFS
May affect,
Likely to
adversely effect
None
designated N/A
Bull trout
(Salvelinus confluentus)
Threatened
(Coastal-Puget
Sound ESU)
USFWS
May Affect,
Likely to
Adversely Affect
Designated
May Affect,
Likely to
Adversely Affect
Bald eagle
(Haliaeetus leucocephalus) Threatened USFWS No Effect None
designated N/A
NMFS – National Marine Fisheries Service 155
USFWS – U.S. Fish and Wildlife Service 156
157
It has also been determined that the Project will adversely affect salmonid EFH. 158
159
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) iv
Table of Contents 160
1. Introduction............................................................................................................................................1 161
1.1 Proposed Project ...........................................................................................................................1 162
1.2 Project Location............................................................................................................................6 163
1.2.1 Project Begin and End Location..............................................................................................9 164
1.2.2 Watershed in Which Project is Located...................................................................................9 165
2. Construction Phasing, Methods, and Conservation Measures.............................................................11 166
2.1 Construction Schedule and Staging............................................................................................11 167
2.1.1 Overview of Construction Schedule......................................................................................11 168
2.1.2 Construction Staging Areas...................................................................................................12 169
2.1.3 Construction Stages...............................................................................................................12 170
2.1.4 Project Components...............................................................................................................12 171
2.1.5 Stormwater Treatment...........................................................................................................27 172
2.1.6 Fish Exclusion and Removal.................................................................................................50 173
2.1.7 Summary of Project Footprint...............................................................................................51 174
3. Project Action Area .............................................................................................................................69 175
3.1 Noise Considerations ..................................................................................................................71 176
3.2 Aquatic Considerations...............................................................................................................72 177
4. Environmental Baseline.......................................................................................................................73 178
4.1 Site History .................................................................................................................................73 179
4.2 Upland Project Setting................................................................................................................76 180
4.3 Physical Indicators......................................................................................................................78 181
4.3.1 Substrate ................................................................................................................................78 182
4.3.2 Streambank Conditions..........................................................................................................78 183
4.4 Chemical Indicators ....................................................................................................................78 184
4.4.1 Water Quality.........................................................................................................................78 185
4.5 Biological Conditions .................................................................................................................80 186
4.5.1 Aquatic...................................................................................................................................80 187
4.5.2 Terrestrial...............................................................................................................................82 188
4.5.3 Summary of USFWS and NMFS Matrix of Pathways and Indicators..................................83 189
5. Species Information, Effects Analysis, and Effects Determination ....................................................87 190
5.1 NMFS-listed Species...................................................................................................................88 191
5.1.1 Chinook Salmon ....................................................................................................................88 192
5.1.2 Puget Sound Steelhead ..........................................................................................................97 193
5.2 USFWS-Listed Species...............................................................................................................99 194
5.2.1 Bull Trout...............................................................................................................................99 195
5.2.2 Bald Eagle............................................................................................................................102 196
5.3 Indirect Effects of Induced Growth ..........................................................................................103 197
5.4 Effects of Interrelated and Interdependent Actions ..................................................................104 198
5.5 Cumulative Effects....................................................................................................................104 199
6. Summary of Project Components, Impacts, and Minimization Measures ........................................107 200
6.1 Summary of BMPs/Minimization Measures.............................................................................107 201
6.2 Summary of Performance Standards.........................................................................................110 202
6.3 Impacts Summary .....................................................................................................................111 203
7. References..........................................................................................................................................113 204
205
206
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) v
Tables 207
Table 1 In-Water Work in Streams..............................................................................................10 208
Table 2 Fish Bearing Culverts Associated with In-water Work..................................................16 209
Table 3 Existing Bridges in the Project Footprint .......................................................................19 210
Table 4 Project Proposed Bridges................................................................................................21 211
Table 5 Summary of Pile Driving for Waterbodies Known or Presumed to Contain ESA 212
Listed Species.................................................................................................................25 213
Table 6 PGIS Surface Areas by Basin.........................................................................................30 214
Table 7 Runoff Treatment Facilities in the Lower Green River Basin........................................31 215
Table 8 Runoff Treatment Facilities in the Black River/ Springbrook Creek Basin...................32 216
Table 9 Runoff Treatment Facilities in the Lower Cedar River Basin........................................33 217
Table 10 Major Detention Facilities for the Project......................................................................35 218
Table 11 Load Calculations for Lower Green River, Black River/Springbrook Creek, and 219
Lower Green River Basins..............................................................................................40 220
Table 12 Concentration Calculations for Lower Green River, Black River/Springbrook Creek, 221
and Lower Green River Basins.......................................................................................41 222
Table 13 Available Cedar River Peaks..........................................................................................43 223
Table 14 Peak Q from On-site Flows to Cedar River from South Outfall ....................................43 224
Table 15 Peak Q from On-site Flows to Cedar River from North Outfall ....................................43 225
Table 16 Peak Flow Increase to Cedar River from Project ...........................................................44 226
Table 17 Peak Velocities From the 100-year Storm in the Cedar River.......................................44 227
Table 18 Peak Velocities at Each Outfall from the 100-year Storm .............................................44 228
Table 19 Background Information for Pollutant Loading and Concentration Analysis................48 229
Table 20 In-Water Work Windows and Species Use....................................................................51 230
Table 21 Area and Lineal Distance of Temporary and Permanent Disturbance to Habitat ..........51 231
Table 22 Potential Permanent Land Cover Loss Within the Project Footprint.............................52 232
Table 23 Summary of Temporary Wetland and Wetland Buffer Effects......................................54 233
Table 24 Summary of Permanent Wetland Effects .......................................................................55 234
Table 25 City of Renton Ratios for Wetlands Creation or Restoration.........................................56 235
Table 26 Ratios for Wetland Restoration or Creation Plus Enhancement.....................................56 236
Table 27 Summary of Temporary River and Stream Effects ........................................................60 237
Table 28 Summary of Permanent River and Stream Effects.........................................................64 238
Table 29 Baseline Land Cover In the Project Footprint................................................................77 239
Table 30 NMFS Overview of the Environmental Baseline Conditions at the Project Action 240
Area Scale and the Watershed Scale ..............................................................................83 241
Table 31 USFWS Overview of Environmental Baseline Conditions at the Project Action Area 242
Scale and the Watershed Scale.......................................................................................85 243
Table 32 Species and Critical Habitat Listed Under the Federal ESA Addressed in this BA and 244
Associated Effects Determinations.................................................................................87 245
Table 33 Species Listed on the Species List but Not Addressed in this BA .................................88 246
247
248
Figures 249
Figure 1 Vicinity Map.....................................................................................................................7 250
Figure 2 Project Footprint...............................................................................................................8 251
Figure 3 Proposed Stormwater Detention Facilities .....................................................................36 252
Figure 4 Wetlands Sheet 1............................................................................................................57 253
Figure 5 Wetlands Sheet 2............................................................................................................58 254
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) vi
Figure 6 Wetlands Sheet 3............................................................................................................59 255
Figure 7 Stream Locations from I-5 to I-405 Interchange to SR 167/I-405 Interchange .............61 256
Figure 8 Stream Locations Along SR 167 ....................................................................................62 257
Figure 9 Stream Locations from SR 167/I-405 Interchange to SR 169/I-405 Interchange..........63 258
Figure 10 Action Area.....................................................................................................................70 259
260
261
Appendices 262
Appendix A Draft Panther Creek Watershed Rehabilitation Plan (PCWRP)...................................A-1 263
Appendix B Essential Fish Habitat...................................................................................................B-1 264
Appendix C Species Lists from USFWS and NMFS........................................................................C-1 265
Appendix D WSDOT Fish Removal Protocol and Standards...........................................................D-1 266
Appendix E Impacts to Aquatic Habitats and Green River Bridge Details...................................... E-1 267
Appendix F Stormwater Pollutants....................................................................................................F-1 268
Appendix G Environmental Baseline for Aquatic Habitats..............................................................G-1 269
Appendix H Tukwila to Renton Improvement Project ESA Analytical Table.................................H-1 270
Appendix I Biology of Listed Species.............................................................................................. I-1 271
272
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 1
1. Introduction 273
1.1 Proposed Project 274
The I-405 Tukwila to Renton Improvement Project (Project) is a Washington State Department of 275
Transportation (WSDOT) project that results in improvements to the Interstate-405 (I-405) and State 276
Route 167 (SR 167) corridors in and around the cities of Renton and Tukwila, Washington. The 277
Project extends approximately 4 miles along I-405, from I-5 to SR 169, and approximately 2 miles 278
along SR 167, from I-405 to SW 43rd Street. It expands on the Renton Nickel Improvement Project, 279
which added one lane in both directions on I-405 between I-5 and SR 167 and between SR 167 and SR 280
169, extended the southbound high-occupancy vehicle (HOV) lane on SR 167 north to I-405, and 281
added one lane southbound on SR 167 between I-405 and SW 41st Street. The constructed Renton 282
Nickel Improvement Project is assumed to be the environmental baseline for the Project for the 283
purposes of this Biological Assessment (BA). 284
285
From I-5 to SR 181, the Project realigns the I-405 roadway near the Westfield Shoppingtown Mall to 286
accommodate improvements near the Green River and SR 181, constructs or modifies six bridges over 287
the Green River, lowers the Green River Trail, and realigns the Interurban Trail. At the I-405/SR 181 288
interchange, the Project reconstructs the south half of the interchange, including extending Tukwila 289
Parkway east to SR 181 over the Green River (one of the six previously mentioned bridges over the 290
Green River) and constructs a new on-ramp from Tukwila Parkway to northbound I-405, and improves 291
the north half of the interchange. 292
293
From SR 181 to SR 167, the Project constructs one additional lane in both directions on I-405. The 294
Project also reconstructs the I-405/SR 167 interchange, including constructing a general purpose 295
direct-connector ramp between southbound I-405 and southbound SR 167, a HOV direct-connector 296
that connects northbound SR 167 with northbound I-405 and southbound SR 167 with southbound I-297
405, and exterior ramps from northbound I-405 to and from SR 167. The Project also shifts local 298
access between Renton and I-405 from SR 167 to new ramps at Lind Avenue and SR 515 (Talbot 299
Road). This new split diamond interchange consists of half-diamond interchanges at Lind Ave and SR 300
515 (Talbot Road) with one-way frontage roads between them. 301
302
From SR 167 to SR 169, the Project constructs two additional lanes in both directions on I-405. The 303
Project also constructs a new I-405 half diamond interchange at SR 515 (Talbot Road) that is 304
connected by one-way northbound and southbound frontage roads. Access between the City of Renton 305
and I-405 shifts to the Lind Avenue and SR 515 half diamond interchanges. Four bridges will be 306
either replaced, reconstructed, or relocated over the Cedar River; these bridges are northbound and 307
southbound I-405, the Burlington Northern Santa Fe (BNSF) Railroad, and a pedestrian bridge. 308
309
Along SR 167, the Project also constructs a northbound auxiliary lane from approximately SW 43rd 310
Street to I-405. The SR 167 mainline is reconstructed from about SW 23rd Street to I-405 for the 311
interchange improvements. 312
313
Improvements are made to local roads and the stormwater drainage system associated with the Project. 314
East Valley Road between SW 16th Street and SW 23rd Street are reconstructed. Two local street 315
accesses to Renton Hill are replaced. The Houser Way bridge is removed and traffic is redirected to 316
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 2
Bronson Way. The Project also includes new stormwater management facilities and a substantial 317
upgrade of existing drainage structures and systems. 318
319
At present, the only portion of the Project that is funded is the I-405, SR 515 Interchange Project (SR 320
515 Project) that is slated for construction beginning in 2008 and ending in 2011. No other stages of 321
the Project have been funded to date. However, a second stage of the Project, the I-405, SR 167 High 322
Occupancy Vehicle Direct Connect Ramp Project (SR 167 HOV Ramp Project) may be constructed 323
should funding become available as a result of the November 2007 Regional Transportation 324
Investment District (RTID) vote. Future Project stages will be constructed as funding becomes 325
available. Mitigation for the individual Project stages will be performed concurrently with the 326
construction of a given Project stage, in accordance with applicable local, state, and federal permitting 327
requirements. 328
329
Project construction will affect some existing cross-culverts. Associated culvert improvements include 330
extending existing structures to accommodate roadway widening, stabilizing culvert ends with rock or 331
retaining walls, and potentially upgrading or replacing culverts to provide for improved fish passage. 332
Other Project components include the use of retaining walls to minimize the construction footprint and 333
to minimize the need for additional right-of-way. Retaining walls will also help avoid and minimize 334
effects to wetlands and other sensitive areas. 335
336
It is anticipated that the Project will use the Design-Build model, in which WSDOT executes a single 337
contract with a Design-Build Contractor (Contractor) for design and construction services to provide a 338
finished product. In this model, WSDOT defines the basic objectives of the Project and develops 339
outcome-based requirements to ensure that the Project is designed and constructed in accordance with 340
environmental regulations. The Contractor is then required to complete the Project in accordance with 341
the outcome-based requirements; however, specific details of design and construction are up to the 342
Contractor to complete. 343
344
Improvements to the Stormwater Management System 345
The design of the Project stormwater improvements will generally utilize as much of existing drainage 346
system as possible and provide treatment facilities that conform to accepted best management practices 347
(BMPs) outlined in the WSDOT Highway Runoff Manual (HRM; WSDOT 2006a). Final design will 348
identify the work involved with highway runoff collection and conveyance, so the extent of reused and 349
new systems is not known at this time. All sites selected for flow control facilities will be placed 350
outside of the 100-year floodplain. Final design may result in changes to the proposed stormwater 351
treatment system, but the Project will not increase pollutant concentrations discharged to receiving 352
waterbodies. Additionally, the construction of any new stormwater facilities will be timed such that 353
the loading and concentration levels that are detailed in this BA will be met or exceeded for each future 354
construction stage. 355
356
The Project will increase the impervious surface areas by 69.60 acres, approximately 30 percent over 357
current conditions. Final design may result in changes to the number, type, size, and location of the 358
proposed drainage facilities for the Project as long as the total BMP catchment area and HRM 359
guidelines are met. The conceptual design includes the following: 360
• Existing stormwater collection and conveyance systems will be modified or additional systems 361
will be constructed as required for the new roadway geometry and as required for stormwater 362
management using equivalent catchment areas. 363
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 3
• Seven new flow control facilities will be constructed. Four existing facilities will be enlarged. 364
Water quality BMPs will be constructed to treat 73.37 acres of new pollution generating surfaces 365
(69.60 net acres including the removal of some existing pollution generating surfaces) plus 63.81 acres 366
of existing pollution generating surface. BMPs treating runoff from the highway will provide 367
enhanced water quality treatment. Treatment facilities for local arterials will provide basic or 368
enhanced treatment depending on the volume of traffic. The net effect of the water quality treatment 369
will reduce the annual pollutant concentrations from highway pavements and local arterials widened 370
within the Project area. 371
372
The conceptual design includes the following stormwater facilities: 373
• One new outfall to the Green River from a new flow control facility located southwest of the 374
new Tukwila Parkway and SR 181 intersection. It is anticipated the outfall will be located 375
above the ordinary high water mark (OHWM) of the Green River; however, portions of the 376
outfall and/or an associated armored outfall pad will occur below the OHWM. 377
• The existing pump facilities at Springbrook Creek will be relocated. 378
• A new outfall from the expanded flow control facility at milepost (MP) 1.6 will discharge to an 379
existing manhole associated with the existing outfall for the Springbrook Pump Station. 380
Discharge from the expanded flow control facility will enter Springbrook Creek through an 381
existing 24-inch-diameter outlet pipe. No improvements are anticipated to this outfall to 382
Springbrook Creek. 383
• The existing outfall on the south side of the Cedar River is anticipated to remain in place. 384
However, based on potential design changes, portions of the outfall and/or an associated 385
armored outfall pad may be constructed below the OHWM. A new outfall pipe from a new 386
spill containment vault will connect to an existing manhole next to the river. This existing 387
manhole is part of the existing outfall system from the south spill containment pond and will 388
remain connected to the existing Cedar River outfall. 389
• The existing outfall on the north side of the Cedar River is also anticipated to remain in place; 390
however, based on potential design changes, portions of the outfall and/or an associated 391
armored outfall pad may be also constructed below the OHWM. A new outfall pipe is proposed 392
from a re-configured spill containment pond to an existing manhole just north of the river. The 393
City of Renton’s storm drainage system ties in to the stormwater system at this manhole. The 394
existing outlet pipe from this manhole discharges to the river. 395
396
For the purposes of this BA, it was assumed that all work below the OHWM of the Green and Cedar 397
Rivers to construct outfalls and associated armored outfall pads will occur as part of the Project. These 398
impacts are included in the impact numbers for the Project. 399
400
Managing stormwater drainage for the Project entails the collection and treatment of a specific range 401
of highway runoff (as defined in the HRM) to mitigate the potential changes associated with the new 402
impervious surface created by the Project. BMPs to treat runoff from the highway will provide 403
enhanced water quality treatment. Enhanced treatment, as defined in the HRM, provides a higher rate 404
of removal of dissolved metals than basic treatment facilities for influent concentrations ranging from 405
0.003 to 0.02 milligrams per liter (mg/L) for dissolved copper and 0.02 to 0.3 mg/L for dissolved zinc. 406
Treatment facilities for local arterials will provide basic or enhanced treatment depending on the 407
volume of traffic. The net effect of the water quality treatment will result in an improvement 408
(decrease) of the average annual pollutant loading of Total Suspended Solids (TSS), total zinc, and 409
total copper from highway pavement and local arterial improvements within the Project area. 410
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 4
Dissolved zinc and copper annual average pollutant loading will increase; however, concentrations of 411
TSS, total and dissolved zinc, and total and dissolved copper will improve (decrease) as a result of the 412
built Project. The runoff that is collected to offset the new pavement areas will be conveyed through 413
quality treatment facilities prior to release into the waterbodies in the action area. 414
415
Flow control will be provided to match peak flows and durations for a specific range of storm 416
recurrence probability from 50 percent of the 2-year event up to the 50-year event. However, flow 417
control will not be provided when discharge is made directly to the Cedar River. WSDOT does not 418
require stormwater detention for discharges to the Cedar River because it is large enough that no 419
measurable increase in hydraulic conditions and velocities will occur with increased runoff. The Cedar 420
River is designated as an exempt waterbody, per updates to the HRM completed in February, 2005 421
(WSDOT 2005a). For Project discharge to tributaries and existing storm drains, the peak rate and 422
duration of discharge will be controlled to match the flows from the Project area per the MGSFlood 423
model (WSDOT 2006d) created for the Project prior to the start of construction. Flow control using 424
infiltration has been generally determined as a non-viable method due to the high groundwater and/or 425
low permeability nature of the soils in the Project area. Thus, flow control has been initially designed 426
using detention storage, primarily in open ponds. 427
428
The Project will adhere to the terms and conditions of the Implementing Agreement between the 429
Washington State Department of Transportation and the Washington State Department of Ecology 430
Regarding Compliance with the State of Washington Surface Water Quality Standards (Implementing 431
Agreement; WSDOT and Ecology 1998), and WAC 173-201(A): Water Quality Standards for Surface 432
Waters of the State of Washington. 433
434
Project Impacts 435
The Project will result in permanent and/or temporary impacts below the OHWM or within the riparian 436
buffers of Gilliam Creek, the Green River, Panther Creek, Rolling Hills Creek, an unnamed tributary to 437
Rolling Hills Creek, Thunder Hills Creek, an unnamed tributary to Thunder Hills Creek, and the Cedar 438
River. A total of 62,291 square feet (1.43 acre) of temporary and 73,616 square feet (1.69 acre) of 439
permanent impact will occur below the OHWM of eight streams/rivers. A total of 3,920 square feet 440
(0.09 acre) of temporary shading and 37,462 square feet (0.86 acres) of permanent shading impacts 441
will occur over four streams/rivers. The Project will result in 39,640 square feet (0.91 acres) of 442
temporary and 293,594 square feet (6.74 acres) of permanent impacts to regulated stream buffers of 443
eight streams. 444
445
The Project will also temporarily impact nine and permanently impact 15 wetlands or their buffers 446
within the study area. Project impacts will result in temporary wetland impacts totaling 45,302 square 447
feet (1.04 acres) and permanent wetland impacts totaling 326,700 square feet (7.50 acres). In addition, 448
17,860 square feet (0.41 acres) of temporary and 351,094 square feet (8.06 acres) of permanent 449
impacts will occur to regulated wetland buffers. 450
451
Mitigation 452
Mitigation will be provided to compensate for the loss of wetland and stream resources within the 453
Project area per requirements of the U.S. Army Corps of Engineers (Corps) Section 404 permit and the 454
Washington State Department of Fish and Wildlife (WDFW) Hydraulic Project Approval (HPA). 455
Wetland and floodplain mitigation for the Project is anticipated to occur at the Springbrook Creek 456
Wetland and Habitat Mitigation Bank (Springbrook Bank). No additional wetland mitigation will be 457
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 5
provided for the Project; however, additional floodplain mitigation will be provided as a result of 458
lowering the Green River Trail during construction of the new Tukwila Parkway bridge. A portion of 459
the stream and river mitigation for the Project will be implemented through the Panther Creek 460
Watershed Rehabilitation Plan (PCWRP). The PCWRP is included in this BA as an element of the 461
Project. The draft PCWRP is included as Appendix A of this BA. 462
463
The PCWRP will provide phased stream mitigation (concurrent and/or advance) at a watershed level 464
for impacts from improvements in the I-405/SR 167 vicinity that affect the Panther Creek and lower 465
Springbrook Creek sub basins. Highway drainage is an important factor affecting streams in the I-405 466
Corridor. The PCWRP also evaluates highway drainage and how it could be cost-effectively managed 467
to compliment the stream mitigation work. 468
469
The benefits of implementing this conceptual plan are to provide: 470
• Stream mitigation for the Project that addresses limiting factors to salmonid production at a 471
watershed level. 472
• Fish habitat improvements via stream flow management to: (1) provide more reliable stream 473
base flows; 2) create stream flow changes that are compatible with wetland floodplain 474
enhancement; and 3) manage stream flows to be compatible with downstream flood control 475
needs. 476
• Preservation of high quality forested wetlands within the contiguous Panther Creek wetland 477
complex. 478
• A direct discharge of treated highway stormwater into the Panther Creek wetland complex that 479
is compatible with the mitigation proposal. The direct discharge is compatible with the 480
mitigation proposal as preliminary engineering analysis shows that wetland hydrology in the 481
Panther Creek Wetland Complex will not be impacted and that wetland surface elevations will 482
not be measurably affected by the direct discharge. 483
484
In addition to the PCWRP, additional mitigation activities are anticipated for Project impacts that will 485
occur in the Green and Cedar Rivers. Due to a lack of dedicated funding for the future stages of the 486
Project that would impact these rivers, specific mitigation activities for impacts to the Green and Cedar 487
Rivers have not been identified. All mitigation activities for impacts to the Green and Cedar Rivers 488
will be performed directly in either the Green or Cedar Rivers (based on where the impact will occur) 489
and will be designed to mitigate for the functions lost as a result of the Project impacts. All mitigation 490
for impacts to the Green and Cedar Rivers will be performed in accordance with the most recent 491
version of the local critical areas ordinances at the time of construction and will compensate for lost 492
functions. Additional aquatic resources mitigation may occur on one or more waterbodies in the 493
vicinity of the Project footprint or at an off-site location. When implemented, all mitigation activities 494
for the Project will adhere to the requirements of the applicable local, state, and federal permits 495
obtained for the Project. 496
497
Relation to Other I-405 Projects 498
The Tukwila to Renton Improvement Project is part of a comprehensive program to address congestion 499
in the I-405 corridor. WSDOT worked with the Federal Highway Administration (FHWA), Federal 500
Transit Administration (FTA), Central Puget Sound Regional Transit Authority, King County, and 501
local governments to develop strategies to reduce traffic congestion along the I-405 corridor. The 502
I-405 Corridor Program Environmental Impact Statement (EIS) and Record of Decision (ROD), 503
published in 2002, document these strategies (WSDOT 2002a, 2002b). The selected alternative 504
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 6
identified in the ROD has become known as the Master Plan. All of the Master Plan projects have 505
been separated into specific project areas, as follows: 506
• I-5 to SR 169 507
• SR 169 to I-90 508
• I-90 to SR 520 509
• SR 520 to I-5 510
511
The first environmental phase of the I-5 to SR 169 Master Plan project is the Renton Nickel 512
Improvement Project. The second environmental phase is the Tukwila to Renton Improvement 513
Project. Future phases of the I-5 to SR 169 Master Plan project have not yet been identified. 514
515
WSDOT will construct the Master Plan in stages as funding becomes available. Two construction 516
stages are presently funded through two statewide transportation funding plans called the “nickel 517
package” and the Transportation Partnership Account (TPA), which were approved by the Washington 518
State Legislature in 2003 and 2005, respectively. Stage 1 constructs one lane in both directions on I-519
405 between I-5 and SR 167 and one lane southbound on SR 167 between I-405 and SW 41st Street. 520
Stage 2 constructs one lane in both directions on I-405 between SR 167 and SR 169, and a half-521
diamond interchange on I-405 at SR 515. Except for the half diamond interchange on I-405 at SR 515, 522
all of the elements of Stages 1 and 2 were cleared under the Renton Nickel Biological Opinion. Future 523
stages of the Master Plan have not been identified. Construction of these funded stages is expected to 524
begin in 2007 and be completed in 2011. 525
526
ESA Listed Species Addressed in this BA 527
This BA addresses impacts to Endangered Species Act (ESA) listed species that may occur in the 528
Project area including: bald eagle (Haliaeetus leucocephalus), bull trout (Salvelinus confluentus), 529
Chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Oncorhynchus mykiss), all of which 530
are listed as threatened under the ESA. It also addresses impacts to Chinook salmon and bull trout 531
critical habitat and Essential Fish Habitat (EFH) within the Project’s action area (see Appendix B). 532
The Cedar and Green Rivers and Springbrook Creek are designated as critical habitat for Chinook 533
salmon (effective January 2, 2006). The Green River is also designated as critical habitat for bull trout 534
(effective October 26, 2005). 535
536
This BA does not address impacts to Canada lynx (Lynx canadensis), grizzly bear (Ursus arctos 537
horribilis), marbled murrelet (Brachyramphus marmoratus marmoratus), northern spotted owl (Strix 538
occidentalis caurina), or golden paintbrush (Castilleja levisecta), which are listed as threatened; marsh 539
sandwort (Arenaria paludicola) or gray wolf (Canis lupus), which are listed as endangered; or fisher 540
(Martes pennanti), which is a candidate species, as these species do not occur in the action area and 541
because no suitable habitat for these species occurs in the action area. Appendix C contains the ESA 542
Species Lists from the U.S. Fish and Wildlife Service (USFWS) and National Marine Fisheries Service 543
(NMFS). 544
545
1.2 Project Location 546
The Project area on I-405 begins just west of the I-5/I-405 interchange and extends north past the 547
Cedar River to just north of the SR 169 interchange. It also includes SR 167 from the I-405 548
interchange to SW 43rd Street. Figure 1 is a vicinity map of the Project and Figure 2 details the 549
Project footprint. 550
Figure 1
Tukwila to Renton Improvement Project
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Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 9
1.2.1 Project Begin and End Location 559
560
State Route/Interstate Milepost Begin Milepost End County
I-405 0.0 4.1 King
SR 167 24.4 26.3 King
561
Beginning of Project 562
State Route/Interstate Section Township Range Latitude Longitude
I-405 (western boundary
of improvements) 23 23N 4E 47.462863N -122.258566W
563
End of Project 564
State Route/Interstate Section Township Range Latitude Longitude
I-405 (eastern boundary
of improvements) 23 23N 5E 47.480775N -122.199758W
SR 167 (southern
boundary of
improvements)
17 23N 5E 47.444232N -122.216684W
565
1.2.2 Watershed in Which Project is Located 566
The Project is located in the Lower Cedar River Subarea of the Lake Washington/Cedar/Sammamish 567
Watershed (Water Resource Inventory Area [WRIA] 8) and the Lower Green River Subwatershed of 568
the Green/Duwamish and Central Puget Sound Watershed (WRIA 9). In-water work related to the 569
Project will occur at the Green River, Gilliam Creek, Rolling Hills Creek, an unnamed tributary to 570
Rolling Hills Creek, Thunder Hills Creek, Panther Creek, and an unnamed tributary to Thunder Hills 571
Creek which are located in WRIA 9 and the Cedar River, which is located in WRIA 8. Of these 572
waterbodies, only the Green River, Gilliam Creek, Panther Creek, and the Cedar River are known or 573
presumed to contain ESA listed species. 574
575
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 10
Table 1 576
In-Water Work in Streams 577
Waterbody
River Mile Work
Location Tributary to WRIA
6th Field Hydrologic Unit
Code (HUC)*
Green River 12.5 Duwamish River;
Elliot Bay 9 Lower Green River:
171100130399
Gilliam Creek No known river mile
information Green River 9 171100130399
Panther Creek 0.55 to 1.45 Springbrook Creek 9 171100130399
Cedar River 1.75 Lake Washington 8 Lower Cedar River:
171101120106
Rolling Hills Creek No known river mile
information Springbrook Creek 9 171100130399
Unnamed Tributary to
Rolling Hills Creek
No known river mile
information Springbrook Creek 9 171100130399
Thunder Hills Creek No known river mile
information Springbrook Creek 9 171100130399
Unnamed Tributary to
Thunder Hills Creek
No known river mile
information Springbrook Creek 9 171100130399
578
* The United States is divided and sub-divided into successively smaller hydrologic units, which are classified into four 579
levels: regions, sub-regions, accounting units, and cataloging units. The hydrologic units are arranged within each other, 580
from the smallest (cataloging units) to the largest (regions). Each hydrologic unit is identified by a unique hydrologic unit 581
code (HUC) consisting of two to eight digits based on the four levels of classification in the hydrologic unit system.582
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 11
2. Construction Phasing, Methods, and Conservation Measures 583
2.1 Construction Schedule and Staging 584
The Project will be constructed in stages based on available funding. This BA covers all stages of the 585
Tukwila to Renton Improvement Project including both funded and unfunded stages. At present, the 586
only portion of the Project that is funded is the SR 515 Project that is slated for construction beginning 587
in 2008 and ending in 2011. The SR 515 Project consists of the following elements: 588
• New on-ramp from SR 515 (Talbot Road) to northbound I-405 589
• New off-ramp from southbound I-405 to SR 515 590
• New detention pond, with associated water quality treatment between Smithers Avenue and SR 591
515, at approximately 14th Street 592
• Retaining walls will be constructed as part of the on-ramp from SR 515 593
• The Renton Village Place entrance will be shifted slightly north to align with the southbound 594
off-ramp 595
• New signals at the ramp terminal intersecting with SR 515 596
• SR 515 will be widened from just north of the new I-405 off-ramp south through the Puget 597
Drive intersection 598
599
No other stages of the Project have been funded to date. However, a second stage of the Project, the 600
SR 167 HOV Ramp Project may be constructed should funding become available. This second stage 601
of the Project has been identified for funding in the RTID Revised Blueprint for Progress dated June 8, 602
2007. Under the present schedule of the Revised Blueprint for Progress, funding for the SR 167 HOV 603
Ramp Project will go to a public vote in November, 2007. Prior to this vote occurring, the overall 604
funding package and schedule may be changed as part of the public process and, therefore, there is no 605
certainty this stage of the Project will be funded. Additional stages of the Project will be constructed 606
as future funding becomes available. The exact number of future stages is undetermined at this time 607
due to the lack of certainty surrounding future Project funding. 608
609
Mitigation for individual Project stages will be performed concurrently with the construction of a given 610
Project stage, in accordance with applicable local, state, and federal permitting requirements. Wetland 611
mitigation for the Project is anticipated to occur at the Springbrook Bank. No additional wetland 612
mitigation is proposed for the Project. Stream and river mitigation will occur on one or more 613
waterbodies in the immediate vicinity of the Project footprint (on-site mitigation) or at an off-site 614
location. The PCWRP will not be used as mitigation for the first stage of the Project. 615
616
All stages of the Project are anticipated to be constructed using a design-build model, where the 617
Contractor(s) are required to complete the Project in accordance with outcome-based requirements 618
prescribed by WSDOT; however, specific details of design and construction, including Project 619
schedule, are up to the Contractor to complete. 620
621
2.1.1 Overview of Construction Schedule 622
The Project will be constructed in stages. The first stage, the SR 515 Project, is the only funded stage 623
of the Project. The SR 515 Project is scheduled for construction between 2008 and 2011. The 624
remaining stages of the Project will be constructed in the future based on available funding. Should 625
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 12
funding become available for the SR 167 HOV Ramp Project, construction is anticipated between 626
2010 and 2012. 627
628
No waterbodies containing ESA listed species or critical habitat for ESA listed species will be 629
impacted as a result of the SR 515 Project. Only Rolling Hills Creek, Thunder Hills Creek, and an 630
unnamed tributary to Thunder Hills Creek would potentially be impacted by this Project. All in-water 631
work for this stage of the Project will adhere to applicable in-water work windows as provided by 632
WDFW and the Corps. 633
634
Future stages of the Project will also involve in-water work in the Green River, Gilliam Creek, Panther 635
Creek, and the Cedar River, which are either known or presumed to contain ESA listed species. The 636
construction elements and associated construction schedules for these stages are undetermined at this 637
time as no funding has been appropriated to construct these additional stages of the Project. As with 638
the SR 515 Project, all in-water work for future stages of the Project will adhere to applicable in-water 639
work windows as provided by WDFW. There are no known ESA listed terrestrial species that occur 640
within the action area and, as such, no additional timing restrictions are proposed for the protection of 641
ESA listed species. 642
643
2.1.2 Construction Staging Areas 644
Construction staging areas will be required for the Project; however, the specific locations of these 645
staging areas will be determined by the Contractor. All construction access sites and staging areas will 646
be constructed in accordance with applicable permit conditions for the Project and WSDOT Standard 647
Specifications. The Contractor shall confine construction activities to the minimum area necessary 648
within environmentally sensitive areas and will be required to follow the conditions of the Temporary 649
Erosion and Sediment Control (TESC) and Spill Prevention, Control and Countermeasures (SPCC) 650
Plans for the Project. Project staging and material storage areas shall be located a minimum of 150 651
feet from surface waters or in currently developed areas such as parking lots or managed fields such as 652
interchange infield areas (e.g., within loop ramps at the SR 167/I-405 interchange). 653
654
2.1.3 Construction Stages 655
The first Project construction stage will be constructed as a design-build project. It is anticipated that 656
future stages of the Project will be constructed as design-build projects and that these stages will be 657
determined as funding becomes available. All in-water work for each stage of the Project will adhere 658
to applicable in-water work windows as determined by WDFW and the Corps. There are no known 659
ESA listed terrestrial species that occur within the action area and, as such, no additional timing 660
restrictions are proposed for the protection of ESA listed species. 661
2.1.4 Project Components 662
The Project components include all the roadway improvements discussed in Section 1.1. In addition, 663
the Project also includes the following components: 664
665
Fish Passage Barriers 666
WSDOT has identified existing culverts in the action area that convey waters of the state, are fish 667
bearing, and will be affected by the Project. Based on the results of the fish passage barrier 668
investigation, WSDOT has determined that there are 10 culverts that meet these criteria. Of these 10 669
culverts, WSDOT has determined that seven of them are existing fish passage barriers. WSDOT will 670
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 13
conduct further evaluation on the seven fish barrier culverts to determine which ones will be retrofitted 671
or replaced as part of the Project. These fish passage barriers are described in greater detail in Section 672
2.1.4.1 – Culvert Replacement 673
674
In-Water Work 675
In-water work will occur in or near several waterbodies that are known or assumed to contain ESA 676
listed species. These waterbodies are the Green River, Gilliam Creek, Panther Creek, and the Cedar 677
River. No in-water pile driving will be performed as part of the Project, as all potential in-water work 678
areas will be isolated and dewatered prior to construction; however, pile driving will occur below the 679
OHWM of the Green River, Gilliam Creek, and Panther Creek during the dewatered conditions. Pile 680
driving is not anticipated in or near the Cedar River. The existing I-405 bridges over the Cedar River 681
are on spread footings. The new I-405 bridges over the Cedar River can be constructed in a similar 682
fashion and the new BNSF and pedestrian bridges will be clear span bridges over the OHWM of the 683
Cedar River that will not require new piling to be constructed. 684
685
In-water work on the Green River consists of removing piling, placement of rip-rap, and associated de-686
watering of the construction area for pile driving and construction of a new stormwater outfall. In-687
water work on Gilliam Creek consists of activities associated with realigning 66th Avenue S and 688
northbound I-405. In-water work on Panther Creek consists of adding a new lane along the east side of 689
northbound SR 167 and additional improvements to the southbound SR 167 mainline, interchange 690
ramps between SR 167 and East Valley Road, and SW 43rd on-ramp that will encroach into the 691
OHWM of Panther Creek. In-water work on the Cedar River will consist of removing piling that 692
support the existing pedestrian bridge (if required for mitigation) and installation of two new 693
stormwater outfalls (on the north and south banks of the Cedar River). 694
695
To minimize effects to listed species from the in-water construction, the following general BMPs will 696
be implemented during the Project: 697
• A TESC Plan will be developed and implemented for all projects requiring clearing, vegetation 698
removal, grading, ditching, filling, embankment compaction, or excavation. The BMPs in the 699
plans will be used to control sediments from all vegetation removal or ground disturbing 700
activities. 701
• All equipment to be used for construction activities shall be cleaned and inspected prior to 702
arriving at the Project site to ensure no potentially hazardous materials are exposed, no leaks 703
are present, and the equipment is functioning properly. Should a leak be detected on heavy 704
equipment used for the Project, the equipment shall be immediately removed from the area and 705
not used again until adequately repaired. 706
• Clearing limits will be delineated with orange barrier fencing prior to commencing clearing 707
activities wherever clearing is proposed in or adjacent to a stream/wetland or its buffer. 708
• Erosion control devices (i.e., silt fence) will be installed as needed to protect surface waters and 709
other critical areas. Actual location will be specified in the field, based upon site conditions. 710
• Erosion control blankets or an equally effective BMP will be installed on steep slopes that are 711
susceptible to erosion and where ground-disturbing activities have occurred. This will prevent 712
erosion and assist with establishment of native vegetation. 713
• Project staging and material storage areas shall be located a minimum of 150 feet from surface 714
waters or in currently developed areas such as parking lots or managed fields such as 715
interchange infield areas (e.g., within loop ramps at the SR 167/I-405 interchange). 716
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 14
• The Contractor will designate at least one employee as the erosion and spill control (ESC) lead. 717
The ESC lead will be responsible for the installation and monitoring of erosion control 718
measures and maintaining spill containment and control equipment. The ESC lead will also be 719
responsible for ensuring compliance with all local, state, and federal erosion and sediment 720
control requirements. 721
• Material that may be temporarily stored for use in Project activities shall be covered with 722
plastic or other impervious material during rain events to prevent sediments from being washed 723
from the storage area to surface waters. 724
• All temporary and permanent erosion and sedimentation control measures will be inspected on 725
a regular basis, maintained, and repaired to ensure continued performance of their intended 726
function. 727
• Silt fences will be inspected immediately after each rainfall, and at least daily during prolonged 728
rainfall. Sediment will be removed as it collects behind the silt fences and prior to their final 729
removal. 730
• Temporary storage of excavated materials will not occur within the 100-year floodplain 731
between October 1 and May 1. Material used within 12 hours of deposition will not be 732
considered temporary. 733
• Exposed soils will be seeded and covered with straw mulch or an equally effective BMP after 734
construction is complete. Any temporary construction impact areas will be revegetated with 735
native plants following final grading activities. 736
• All exposed soils will be stabilized during the first available period and no soils shall remain 737
unstabilized for more than 2 days from October 1 to April 30, and for more than 7 days from 738
May 1 to September 30. 739
• All silt fencing and staking will be removed upon Project completion. 740
• A concrete truck chute cleanout area or equally effective BMP shall be established to properly 741
contain wet concrete. 742
• A 3-year monitoring plan of revegetated areas will be implemented to ensure 100 percent 743
survival of vegetation by stem count at the end of 1 year and 80 percent survival by stem count 744
at the end of the 3-year monitoring period. 745
• Before, during, and immediately after isolation and dewatering of the in-water work area, fish 746
from the isolated area will be captured and released using trapping, seining, electrofishing, or 747
other methods as to minimize risk of injury to fish, in accordance with the WSDOT Protocols 748
for such activities (Appendix D). 749
• The Contractor shall prepare a SPCC Plan prior to beginning construction. The SPCC Plan 750
shall identify the appropriate spill containment materials, which will be available at the Project 751
site at all times. 752
• Seasonal restrictions (i.e., work windows) will be applied to the Project to avoid or minimize 753
potential impacts to listed species based on the HPA issued by WDFW and consultation with 754
USFWS and NMFS. The appropriate in-water work windows for this Project for the Green 755
River, Gilliam Creek, Panther Creek, and the Cedar River are from June 15 to September 30 756
each year for the protection of salmonids including Chinook salmon, bull trout, and steelhead 757
trout. 758
• The Contractor will develop a SPCC Plan, TESC Plan, and a Hydraulic Report for the Project. 759
• All in-water work will conform to the requirements of the HPA issued for the Project. 760
• All construction activities will comply with water quality standards set forth in the 761
Implementing Agreement (WSDOT and Ecology 1998) and the State of Washington Surface 762
Water Quality Standards (WAC 173-201A). The current WSDOT/Ecology Water Quality 763
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 15
Implementing Agreement allows for a mixing zone not to exceed a specified distance 764
downstream of the Project corridor based on the characteristics of the waterbody. 765
• For projects that require placement of clean rock below the OHWM, clean rock shall consist of 766
various types and sizes, depending upon application, that contains no fines, soils, or other 767
wastes or contaminants. 768
• Revegetation of construction easements and other areas will occur either during or after the 769
Project is completed. All disturbed riparian vegetation will be replanted. Trees will be planted 770
when consistent with highway safety standards. Riparian vegetation will be replanted with 771
species native to the action area. 772
• Where practicable, excavation activities shall be accomplished in the dry. All surface water 773
flowing toward the excavation shall be diverted through utilization of cofferdams and/or berms. 774
Cofferdams and berms must be constructed of sandbags, clean rock, steel sheeting, or other 775
non-erodible material. 776
• Coffer dams will not be installed with an impact driver. Coffer dams will be installed with a 777
vibratory driver or another method as approved by WSDOT. 778
• All work will be performed according to the requirements and conditions of the HPA issued by 779
WDFW and appropriate terms and conditions identified by USFWS and NMFS (the Services) 780
during ESA consultation. All in-water work will occur during the approved in-water work 781
window, as stipulated by the HPA and ESA consultation. 782
• Bank shaping shall be limited to the minimum necessary. 783
• No paving, chip sealing, or stripe painting will occur during periods of rain or wet weather. 784
• If equipment use within the wetted perimeter of a wetland, stream, or river is permitted, the 785
following provisions shall apply: 786
1. Equipment shall be thoroughly cleaned of mud, petroleum products, or other deleterious 787
material. 788
2. Turning and spinning within the streambed shall be avoided. 789
3. The streambed shall be returned to pre-Project conditions at Project completion. 790
4. The amount and duration of in-stream work with machinery will be limited to the 791
minimum necessary to complete the work. 792
• There will be no visible sheen from petroleum products in the receiving water as a result of 793
Project activities. 794
• WSDOT policy and construction administration practice is to have a WSDOT Environmental 795
Compliance Assurance Inspector on site during construction. The inspector will ensure that 796
contract and permit requirements are met. 797
• WSDOT environmental staff will provide guidance and instructions to the Environmental 798
Compliance Assurance Inspector to ensure the inspector is aware of permit requirements. 799
• No excavated material will be placed in the existing stream channels. Excavated material will 800
be removed to a location that will prevent its reentry into waters of the State. 801
• When practicable, the Contractor shall fuel and maintain all equipment more than 200 feet from 802
the nearest wetland, drainage ditch, or surface waterbody (fueling large cranes, pile drivers, and 803
drill rigs over 200 feet away may not be practical) or in currently developed areas such as 804
parking lots or managed fields. 805
• The amount of riprap will be minimized to the greatest extent possible. 806
807
Additional BMPs specific to culvert replacement, bridge replacement, and pile driving are contained in 808
the following sections. 809
810
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 16
2.1.4.1 Culvert Replacement 811
WSDOT has identified 10 existing culverts in the action area that convey waters of the State, are fish 812
bearing, and will be affected by the Project. Based on the results of the fish passage barrier 813
investigation, WSDOT has determined that seven of these 10 culverts are existing fish passage 814
barriers. WSDOT will conduct further evaluation on the seven fish barrier culverts to determine which 815
ones will be retrofitted or replaced as part of the Project. The 10 culverts are detailed in Table 2. 816
Additional culverts in the action area that will be affected by the Project and do not convey waters of 817
the state, have not been determined to be fish bearing, or where in-water work will not occur are not 818
discussed in this section. 819
820
Table 2 821
Fish Bearing Culverts Associated with In-water Work 822
Stream
Conveyed
Culvert
ID
Culvert
Type
Culvert
Length
(feet)
Upstream
Habitat
(linear feet)*
Fish
Bearing
Fish
Passable
Barrier
Description ESA Species
Gilliam
Creek 14
108
inch
CMP
1103 600 to 800 Yes Yes N/A
Presumed:
Chinook salmon
and steelhead
Known: None
Gilliam
Creek 17
108
inch
CMP
207 1,300 to
2,600 Yes Yes** N/A
Presumed:
Chinook salmon
Known: None
Rolling
Hills
Creek
42 48 inch
CONC 551 10,200*** Yes No
Temporal
barrier based
on velocity
None
Rolling
Hills
Creek
44
132
inch
CMP
918 6,250*** Yes No
Pipe exceeds
velocity criteria
at high fish
passage
design flow
None
Tributary
to Rolling
Hills
Creek
48 30 inch
CONC 281 200 Yes No
Pipe exceeds
velocity and
water depth
criteria at high
fish passage
design flow
None
Thunder
Hills
Creek
52 48 inch
CONC 466 100 Yes No
Pipe exceeds
velocity criteria
at high fish
passage
design flow
None
Panther
Creek 65 24 inch
CMP 155 2,600 Yes No
Pipe exceeds
velocity criteria
at high fish
passage
design flow
Known:
Chinook salmon
Presumed:
steelhead
Panther
Creek 66 30 inch
CMP 153 2,600 Yes No
Pipe exceeds
velocity criteria
at high fish
passage
design flow
Known:
Chinook salmon
Presumed:
steelhead
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 17
Stream
Conveyed
Culvert
ID
Culvert
Type
Culvert
Length
(feet)
Upstream
Habitat
(linear feet)*
Fish
Bearing
Fish
Passable
Barrier
Description ESA Species
Panther
Creek 72 72 inch
Steel 189 7,100 Yes No
Temporal
barrier based
on velocity
Known:
Chinook salmon
Presumed:
steelhead
Rolling
Hills
Creek
76
3-foot
by
4-foot
box
265
N/A****
(fish
passable)
Yes Yes N/A None
* All habitat gains are approximations based on field reconnaissance and are rounded to the nearest hundred foot increment.
** A large metal flap gate (which controls high flows) and a splash pad are located at the end of this culvert. The flap gate
and splash pad on downstream end of the culvert prevent fish from moving up or downstream when it is closed. This
culvert is owned by the City of Tukwila.
*** Culverts 42 and 44 both carry the main flow of Rolling Hills Creek underneath the I-405/SR 167 interchange. As such,
they must be considered together for purposes of fish passage. Culvert 44 is an overflow culvert and only conveys flow
during high flow events.
**** No upstream habitat length is identified for this culvert as it is presently fish passable with no other fish passage barriers in
the immediate vicinity that would prohibit use of this stream segment by fish species.
CMP = corrugated metal pipe CONC = concrete
823
Replacing any of the culverts detailed in Table 2 with new fish passable structures will require in-water 824
work on the stream or river where the culvert is located. Any culvert work requiring an HPA will be 825
investigated to determine if the culvert should be made fish passable per current policies and 826
regulations. However, in certain circumstances WSDOT may provide habitat enhancement in lieu of 827
replacing a fish passage barrier. If enhancement is used, the enhancement will be designed as much as 828
practicable to offset the loss of function provided by habitat upstream of that culvert until such time as 829
the barrier can be replaced. If the culvert is a barrier to listed species, enhancement will be to habitat 830
used by listed species. 831
832
Work below the OHWM will be conducted during the WDFW in-water work windows and any 833
associated fish exclusion will be conducted in accordance with WSDOT’s fish removal and exclusion 834
protocols found in Appendix D of this BA. Stream and river bypasses or dewatering will occur during 835
the driest time of the year when fish are least likely to be present and will be performed in accordance 836
with applicable permit conditions and WSDOT Standard Specifications. 837
838
The dewatering treatment method, if required, will be determined by the Contractor. The Contractor 839
shall adhere to National Pollution Discharge Elimination System (NPDES) construction permit 840
requirements and shall follow Section 401 Water Quality Certification conditions. All applicable state 841
and local water quality standards will be complied with and the most stringent standards will be 842
followed. In addition, the Contractor will be required to follow applicable permit conditions for the 843
Project and the conditions of the TESC and SPCC plans for the Project. 844
845
All Project deleterious materials will be contained, retrieved, and disposed of at an approved upland 846
disposal site. Any mitigation required for the culvert removal, installation of new culverts, or 847
extension of existing culverts will be conducted in accordance with applicable local, state, and federal 848
permitting requirements. 849
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 18
850
Roads and Staging Areas 851
The final design for the Project has not been determined, including where Project-related equipment 852
and materials will be staged/stored during construction. All access roads and staging areas for the 853
Project will occur within the Project footprint shown in Figure 2 unless additional staging areas are 854
required by the Contractor. Should additional access roads or staging areas be required by the 855
Contractor, they will be constructed in accordance with permit conditions for the Project and WSDOT 856
Standard Specifications. In addition, the Contractor will be required to follow the conditions of the 857
TESC and SPCC Plans for the Project. Within or near environmentally sensitive areas, the Contractor 858
shall also confine construction activities to the minimum area necessary to construct an access road. 859
Staging and material storage areas shall be located a minimum of 150 feet from surface waters or in 860
currently developed areas such as parking lots or managed fields such as interchange infield areas (e.g., 861
within loop ramps at the SR 167/I-405 interchange). 862
863
The Contractor will determine the appropriate equipment to complete this activity. 864
865
2.1.4.2 Minimization Measures for Culvert Replacement 866
The Contractor will adhere to the following minimization measures for any culvert replacements and 867
associated access roads or staging areas: 868
• The Contractor shall not place temporary material storage piles, including rebar, precast 869
concrete pipe, steel pipe, and other hard items, in the 100-year floodplain between October 1 870
and May 1. Material used within 12 hours of deposition will not be considered a temporary 871
material storage pile. 872
• All temporary material storage piles will be protected by appropriate BMPs to prevent 873
sediments from leaving the piles and entering surface waters. 874
• When practicable, the Contractor shall fuel and maintain all equipment more than 200 feet from 875
the nearest wetland, drainage ditch, or surface waterbody (fueling large cranes, pile drivers, and 876
drill rigs over 200 feet away may not be practical). 877
• All replacement culverts will be designed and installed in accordance with the WDFW manual 878
Fish Passage Design at Road Culverts: A design manual for fish passage at road crossings 879
(Bates et al. 1999). 880
881
2.1.4.3 Bridge Replacement 882
In total, 10 bridges over waterbodies containing or assumed to contain ESA listed species will be 883
replaced, reconstructed, or relocated as part of the Project: six over the Green River and four over the 884
Cedar River. The six bridges over the Green River include widening, reconstruction, or replacement of 885
I-405 northbound, I-405 southbound, Southcenter Boulevard, SR 181/southbound I-405 interchange 886
ramps, and Interurban Avenue bridges; and construction of a new Tukwila Parkway bridge. The four 887
bridges over the Cedar River include reconstruction or replacement of I-405 northbound, I-405 888
southbound, and BNSF bridges, and a pedestrian bridge. The BNSF bridge superstructure will be 889
moved to a new constructed foundation located immediately west of the existing BNSF bridge 890
location. The new BNSF bridge foundation will be located outside of the OHWM of the Cedar River. 891
For each new or reconstructed bridge, the Contractor will determine the bridge foundation type and 892
bridge superstructure type. The bridges to be widened will likely match the foundation type of the 893
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 19
existing bridges. Additionally, the existing Houser Way vehicle and pedestrian bridges will be 894
removed as part of the Project. All Project bridges will be designed for a 50 year minimum design life. 895
896
All of the new Cedar River bridges will be free spanned over the OHWM of the Cedar River. 897
Opportunities for free spanning the new Green River bridges were examined early in the design 898
process, but it was determined that free spanning all of the bridges over the Green River would not be 899
practicable due to existing constraints. To free span all of the bridges over the Green River, retaining 900
wall heights and fill quantities would be significantly increased, existing property accesses would be 901
restricted, and the Southcenter bridge over the Green River would have to be completely replaced (as 902
opposed to being widened). Thus, restricting the placement of piers for existing bridges over the 903
Green River to outside the OHWM of the Green River was determined to not be practicable. The new 904
Tukwila Parkway bridge will be free spanned over the Green River. Appendix E contains details of 905
the proposed bridges over the Green River. 906
907
For each existing bridge, the Contractor will determine the method of removal. Foundations of 908
existing structures will likely be removed to 2 feet below the finished ground elevation, the adjacent 909
ground elevation, or the natural stream bottom as specified in the WSDOT Standard Specifications. 910
The existing bridge will be disposed of as specified in the WSDOT Standard Specifications. Existing 911
bridge materials to be removed will be prevented from entering waterbodies. 912
913
The length of the new overwater roadway bridges are too short to require any storm water collection 914
system on the bridges themselves. A gutter system on each overwater roadway bridge will collect 915
stormwater, and direct it through the stormwater conveyance system for treatment and ultimate 916
discharge. Details on piles to be installed for each bridge, where applicable, are provided in Section 917
2.1.4.5 – Pile Driving. 918
919
Table 3 details information on the existing bridges and potential removal methods. Table 4 details 920
information on the proposed bridges including proposed construction sequencing. 921
922
Table 3 923
Existing Bridges in the Project Footprint 924
Bridge Name Bridge Type
Bridge
Materials
Existing
Bridge Area
(Square Feet)
Portion of
Bridge Below
OHWM Additional Information
NB I-405 over
the Green
River
Cast in Place
(CIP)
Reinforced
Concrete Box
Girder
Concrete
and Steel 19,600 Two piers*
The bridge will be dismantled by
sections and removed by crane
to trailers or containers to be
towed off site.
SB I-405 over
the Green
River
CIP
Reinforced
Concrete Box
Girder
Concrete
and Steel 19,800 Two piers*
The bridge will be dismantled by
sections and removed by crane
to trailers or containers to be
towed off site.
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 20
Bridge Name Bridge Type
Bridge
Materials
Existing
Bridge Area
(Square Feet)
Portion of
Bridge Below
OHWM Additional Information
Southcenter
Boulevard
over the
Green River
Prestressed
Concrete
Girder
Prestressed
Concrete,
Concrete
and Steel
17,600 Two piers*
This bridge will be widened. The
existing barrier, sidewalk, and
slab cantilever will be removed.
Falsework supported on the
existing bridge will be used to
contain demolition debris.
SR 181/SB I-
405 ramps
over the
Green River
Prestressed
Concrete
Girder
Prestressed
Concrete,
Concrete
and Steel
18,600 Two piers*
This bridge will be widened. The
existing barrier, sidewalk, and
slab cantilever will be removed.
Falsework supported on the
existing bridge will be used to
contain demolition debris.
Interurban
Avenue over
the Green
River
Prestress
Concrete
Girder
Prestressed
Concrete,
Concrete
and Steel
17,600 Two piers*
It is anticipated that the existing
bridge will be dismantled and
removed by crane to trailers or
containers to be towed off-site.
SB I-405 over
the Cedar
River
Steel Plate
Girder
Concrete
and Steel 37,000 None
It is anticipated that the existing
bridge will be dismantled and
removed by crane to trailers or
containers to be towed off-site.
NB I-405 over
the Cedar
River
Steel Plate
Girder
Concrete
and Steel 43,800 None
It is anticipated that the existing
bridge will be dismantled and
removed by crane to trailers or
containers to be towed off-site.
BNSF over
the Cedar
River
Steel Plate
Girder
Concrete
and Steel 3,000 None
The proposed location of the
new bridge is west of the existing
bridge. The superstructure of
the existing bridge will be moved
to the new location of the
proposed bridge once the new
substructure is constructed.
Pedestrian
bridge over
the Cedar
River
Steel Plate
Girder
Concrete
and Steel 3,900 One pier
It is anticipated that the existing
bridge will be dismantled and
removed by crane to trailers or
containers to be towed off-site.
Existing pier may be removed for
mitigation.
Houser Way
vehicular
bridge over
the Cedar
River
Steel Plate
Girder
Concrete
and Steel 4,300 None
It is anticipated that the existing
bridge will be dismantled and
removed by crane to trailers or
containers to be towed off-site.
Houser Way
pedestrian
bridge over
the Cedar
River
Precast
Concrete
Girder
Prestressed
Concrete,
Concrete
and Steel
1,000 None
It is anticipated that the existing
bridge will be dismantled and
removed by crane to trailers or
containers to be towed off-site.
* The portion of the bridge below OHWM references a pier location, which is a row of columns generally parallel to the
stream flow
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 21
Table 4 925
Project Proposed Bridges 926
Bridge
Name
Location of
New
Bridge
Supports
Required
excavation,
grading, or
grubbing Construction Methods for New Bridge
Bridge Deck
Installation Methods
NB I-405
over the
Green River
Abutments
will be
outside the
OHWM.
Piers will be
located
within the
OHWM.
Excavation
required for
construction of
new abutments,
piers, and
removal of the
existing bridge
foundation
1 Install either drilled shafts or piles for the
piers and abutments.
2 Install pier columns, pier caps, and
abutments.
3 Set girders or pour concrete
superstructure as applicable to the
Design-Builder's proposed bridge type.
4 Install bridge deck.
5 Install barrier.
1 Place formwork for
the deck.
2 Place reinforcing
steel.
3 Pour concrete deck.
4 Cure concrete deck.
5 Strip formwork.
SB I-405 over
the Green
River
Abutments
will be
outside the
OHWM.
Piers will be
located
within the
OHWM.
Excavation
required for
new abutments,
piers, and
removal of the
existing bridge
foundation
1 Install either drilled shafts or piles for the
piers and abutments.
2 Install pier columns, pier caps, and
abutments.
3 Set girders or pour concrete
superstructure as applicable to the
Design-Builder's proposed bridge type.
4 Install bridge deck.
5 Install barrier.
1 Place formwork for
the deck.
2 Place reinforcing
steel.
3 Pour concrete deck.
4 Cure concrete deck.
5 Strip formwork.
Southcenter
Boulevard
over the
Green River
Abutments
will be
outside the
OHWM.
Pier
widening
will be
located
within the
OHWM.
Excavation
required for
new abutments,
piers, and the
widened portion
of the bridge
1 Demolish existing barrier, sidewalk, and
slab cantilever.
2 Install foundation for widened portion of
bridge (footing on either drilled shafts or
driven piles anticipated).
3 Install pier columns, pier caps, and
abutments.
4 Set girders.
5 Install deck.
6 Install barrier.
1 Saw cut the existing
deck at the exterior
girder.
2 Place formwork for
the deck.
3 Place reinforcing
steel.
4 Pour concrete deck.
5 Cure concrete deck.
6 Strip formwork.
SR 181/SB
I-405 ramps
over the
Green River
Abutments
will be
outside the
OHWM.
Pier
widening
will be
located
within the
OHWM.
Excavation
required for
new abutments,
piers, and the
widened portion
of the bridge
1 Demolish existing barrier, sidewalk, and
slab cantilever.
2 Install foundation for widened portion of
bridge (footing on either drilled shafts or
driven piles anticipated).
3 Install pier columns, pier caps, and
abutments.
4 Set girders.
5 Install deck.
6 Install barrier.
1 Saw cut the existing
deck at the exterior
girder
2 Place formwork for
the deck.
3 Place reinforcing
steel.
4 Pour concrete deck.
5 Cure concrete deck.
6 Strip formwork.
Interurban
Avenue over
the Green
River
Abutments
will be
outside the
OHWM.
Piers will be
located
within the
OHWM.
Excavation
required for
new abutments,
piers, and
removal of the
existing bridge
foundation
1 Install either drilled shafts or piles for the
piers and abutments.
2 Install pier columns, pier caps, and
abutments.
3 Set girders or pour concrete
superstructure as applicable to the
Design-Builder's proposed bridge type.
4 Install bridge deck.
5 Install barrier.
1 Place formwork for
the deck.
2 Place reinforcing
steel.
3 Pour concrete deck.
4 Cure concrete deck.
5 Strip formwork.
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 22
Bridge
Name
Location of
New
Bridge
Supports
Required
excavation,
grading, or
grubbing Construction Methods for New Bridge
Bridge Deck
Installation Methods
Tukwila
Parkway over
the Green
River
Bridge
supports
will be
located
outside of
the OHWM.
Excavation
required for
new abutments
and piers
1 Install either drilled shafts or piles for
abutments.
2 Install abutments.
3 Set girders.
4 Install deck.
5 Install barrier.
1 Place formwork for
the deck.
2 Place reinforcing
steel.
3 Pour concrete deck.
4 Cure concrete deck.
5 Strip formwork.
SB I-405 over
the Cedar
River
Bridge
supports
will be
located
outside of
the OHWM.
Excavation
required for
new abutments,
piers, and
removal of the
existing bridge
foundation
1 Install bridge foundation.
2 Install pier columns, pier caps, and
abutments.
3 Set girders.
4 Install bridge deck.
5 Install barrier.
1 Place formwork for
the deck.
2 Place reinforcing
steel.
3 Pour concrete deck.
4 Cure concrete deck.
5 Strip formwork.
NB I-405
over the
Cedar River
Bridge
supports
will be
located
outside of
the OHWM.
Excavation
required for
new abutments,
piers, and
removal of the
existing bridge
foundation
1 Install bridge foundation.
2 Install pier columns, pier caps, and
abutments.
3 Set girders.
4 Install bridge deck.
5 Install barrier.
1 Place formwork for
the deck.
2 Place reinforcing
steel.
3 Pour concrete deck.
4 Cure concrete deck.
5 Strip formwork.
BNSF over
the Cedar
River
Bridge
supports
will be
located
outside of
the OHWM.
Excavation
required for
new abutments,
piers, and
removal of the
existing bridge
foundation
1 Install pier and abutment foundations.
2 Install pier columns, pier caps, and
abutments.
3 Relocate the existing superstructure
(girders and deck) to the proposed bridge
site for span over Cedar River.
4 Install ballast, ties, and railroad tracks.
5 Shift railroad traffic to the new bridge.
1 Remove ballast,
ties, and tracks from
deck.
2 Relocate
superstructure to
new foundations.
3 Install ballast, ties,
and tracks.
Pedestrian
bridge over
the Cedar
River
Bridge
supports
will be
located
outside of
the OHWM.
Excavation
required for
new abutments,
piers, and
removal of the
existing bridge
foundation
1 Install bridge foundation.
2 Install abutments.
3 Set girders.
4 Install deck.
5 Install barrier.
1 Place formwork for
the deck.
2 Place reinforcing
steel.
3 Pour concrete deck.
4 Cure concrete deck.
5 Strip formwork.
927
In addition to the new permanent bridges detailed in Table 4, two temporary piers will likely need to 928
be constructed for the new Tukwila Parkway bridge over the Green River. The purpose of the 929
temporary piers is to support the steel or concrete girders in the field until they can be spliced. Both 930
piers will be installed and removed within the WDFW-approved in-water work windows for the 931
Project. Construction of these temporary piers will require up to 50 additional temporary piles to be 932
installed. The temporary piles will be partially or wholly removed upon completion of the Tukwila 933
Parkway bridge, as specified in the WSDOT Standard Specifications. Work on the bridges on the 934
Green and Cedar Rivers will be performed from shore or the existing bridges. Temporary bridges will 935
not be required within the OHWM of the Cedar River. In addition, work in and around Panther Creek 936
will not require construction of temporary bridges. Any staging areas or access roads required to 937
construct the bridges will be constructed in accordance with permit conditions for the Project and 938
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 23
WSDOT Standard Specifications. In addition, the Contractor will be required to follow the conditions 939
of the TESC and SPCC Plans for the Project. Within or near environmentally sensitive areas, the 940
Contractor shall also confine construction activities to the minimum area necessary to construct an 941
access road. Staging and material storage areas shall be located a minimum of 150 feet from surface 942
waters or in currently developed areas such as parking lots or managed fields such as interchange 943
infield areas (e.g., within loop ramps at the SR167/I-405 interchange). 944
945
Dewatering and associated fish exclusion will be required to remove or construct bridges. Stream and 946
river bypasses or dewatering will be performed in accordance with applicable permit conditions and 947
WSDOT Standard Specifications. Fish exclusion will be conducted in accordance with WSDOT’s fish 948
removal and exclusion protocols found in Appendix D of this BA. 949
950
The method of treatment of dewatering water, if required, will be determined by the Contractor. The 951
Contractor shall adhere to NPDES construction permit requirements and shall follow Section 401 952
Water Quality Certification conditions. All applicable state and local water quality standards will be 953
complied with and the most stringent standards will be followed. 954
955
WSDOT will require the Design-Builder to perform a scour analysis to evaluate the need for bank 956
stabilization for each bridge in the Project. The scour analysis will be used to determine whether there 957
will be a need to place new or remove existing bank stabilization features (e.g. riprap, large woody 958
debris [LWD], etc.). The scour analysis will also be used to determine whether construction activities 959
will create hydraulic changes that may affect bank or channel stabilization elsewhere in a given 960
waterbody. 961
962
This BA assumes that bank stabilization will be required for the Green River bridges and new outfalls 963
to the Green and Cedar Rivers, and presents a worst-case scenario for the extent of impacts. Impacts to 964
aquatic habitats are detailed in Section 2.1.7.2 and Appendix E. When constructing bank stabilization 965
measures, the Contractor will be required to follow the Washington State Aquatic Guidelines 966
Integrated Streambank Protection Guidelines (ISPG 2002) or Bridge Scour and Stream Instability 967
Countermeasures: Experience, Selection, and Design Guidance, Hydraulic Engineering Circular No. 968
23 (HEC 23) for Project components that require bank stabilization. In addition, the Contractor will be 969
required to follow WSDOT Standard Specifications and all permit conditions associated with 970
placement of bank stabilization. 971
972
2.1.4.4 Minimization Measures for Bridge Replacement/Bank Stabilization 973
The Contractor will adhere to the following BMPs for any bridge replacement or bank stabilization 974
activities: 975
• Accumulations of bird feces, road grit, sand, and loose paint chips shall be removed to the 976
greatest extent practicable prior to disassembling the existing bridge. 977
• Drip tarps shall be suspended below paint platforms to prevent spilled paint, buckets, brushes, 978
etc. from entering State waters. 979
• Pressure washing of bridge structures shall be done using appropriate screened tarping to 980
control and contain paint particles generated by the activity. Concentrated accumulations of 981
bird feces and nests shall not be allowed to drop into the water. This material shall be scraped 982
from the bridge structure and collected and disposed of at an appropriate upland location. 983
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 24
• During abrasive blasting of a steel bridge prior to painting, a containment system appropriate 984
for the type and location of the bridge shall be in place and maintained to prevent spent blast 985
media from reaching State waters. Spent blast media shall be collected, sampled, designated 986
for its hazardous material content, and disposed of as appropriate for its waste designation. 987
• Debris accumulations on the bridge, road surface, and within the bridge drains shall be 988
collected or swept up and properly disposed of prior to fresh water flushing. Flushing will 989
involve the use of clean water only, to prevent detergents or other cleaning agents from 990
entering waters of the State. 991
• The Contractor shall protect all inlets and catchments from fresh concrete, tackifier, paving, or 992
paint stripping. 993
• Installation of riprap and other bank stabilizing materials will occur from the banks or outside 994
the wetted perimeter as much as possible. 995
• The Project will follow the ISPG or the HEC 23 (FHWA) recommendations as much as 996
practicable. 997
• Living plant material and LWD will be incorporated in the bank protection designs where 998
appropriate. 999
• At the end of each workday, the work area within the OHWM shall contain no pits, potholes, or 1000
depressions to avoid stranding of fish. 1001
• Temporary construction piers will be installed and removed within the WDFW-approved in-1002
water work windows for the Project. 1003
• The Contractor will be required to use the minimum amount of bank stabilization measures 1004
necessary to construct the Project as determined from the scour analysis. 1005
1006
2.1.4.5 Pile Driving 1007
The Project may require installation of piling for retaining walls, flyover ramps, and for supports at 1008
bridges (including six bridges over the Green River). Pile driving is not anticipated at the four bridges 1009
over the Cedar River. The Green River is the only waterbody in the Project area containing or 1010
assumed to contain ESA listed species where pile driving below the OHWM will occur during 1011
dewatered conditions. No in-water pile driving will be performed as part of the Project as all potential 1012
in-water work areas will be isolated and dewatered prior to construction commencing. 1013
1014
Additionally, piles for the southbound I-405 to southbound SR 167 flyover ramp will be driven within 1015
or within the proximity of the OHWM of Rolling Hills Creek and the unnamed tributary to Rolling 1016
Hills Creek during dewatered conditions. Piles may also be driven in or near wetlands to install 1017
retaining walls for the Project. The remaining piles for the Project will be driven in upland areas. 1018
1019
The final design for the Project has not been determined, including all specific areas where pile driving 1020
may occur. Additional pile driving may be required at other sites in the Project area based on the final 1021
Project design; however, no pile driving below the OHWM of waterbodies containing ESA listed 1022
species will occur beyond that discussed above for the Green River. 1023
1024
Existing piles will likely be removed to 2 feet below the finished ground elevation, the adjacent ground 1025
elevation, or the natural stream bottom as specified in the WSDOT Standard Specifications. 1026
1027
Table 5 is a summary of pile driving activities for waterbodies known or presumed to contain ESA 1028
listed species. 1029
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 25
Table 5 1030
Summary of Pile Driving for Waterbodies Known or Presumed to Contain ESA Listed Species 1031
Structure Depth (of water) Piles Removed Piles Installed
NB I-405 over the Green
River
Approximately 20 foot
(distance from OHWM to
bottom of channel);
approximately 5 foot
(distance from low water to
bottom of channel)
0* 260 piles (110 below
OHWM)
SB I-405 over the Green
River
Approximately 20 foot
(distance from OHWM to
bottom of channel);
approximately 5 foot
(distance from low water to
bottom of channel)
0* 200 piles (80 below
OHWM)
Southcenter Boulevard over
the Green River
Approximately 20 foot
(distance from OHWM to
bottom of channel);
approximately 5 foot
(distance from low water to
bottom of channel)
0* 60 piles (30 below
OHWM)
SR 181/SB I-405 ramps over
the Green River
Approximately 20 foot
(distance from OHWM to
bottom of channel);
approximately 5 foot
(distance from low water to
bottom of channel)
0* 60 piles (10 below
OHWM)
Interurban Avenue over the
Green River
Approximately 20 foot
(distance from OHWM to
bottom of channel);
approximately 5 foot
(distance from low water to
bottom of channel)
0* 240 piles (60 below
OHWM)
Tukwila Parkway over the
Green River
Approximately 20 foot
(distance from OHWM to
bottom of channel);
approximately 5 foot
(distance from low water to
bottom of channel)
N/A – New
bridge
No permanent in-water
piling anticipated;
number of piling
outside of OHWM to
be determined by the
Contractor
Temporary platform to
construct Tukwila Parkway
Bridge over the Green River
Approximately 20 foot
(distance from OHWM to
bottom of channel);
approximately 5 foot
(distance from low water to
bottom of channel)
N/A – New
temporary bridge
50 (all below OHWM)
SB I-405 over the Cedar
River
No piles anticipated to be
driven in water
N/A – Existing
bridge has
spread
footings**
No piles anticipated
NB I-405 over the Cedar
River
No piles anticipated to be
driven in water
N/A – Existing
bridge has
spread
footings**
No piles anticipated
BNSF over the Cedar River No piles anticipated to be
driven in water
0* No piles anticipated
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 26
Structure Depth (of water) Piles Removed Piles Installed
Pedestrian bridge over the
Cedar River
Approximately 20 foot
(distance from OHWM to
bottom of channel);
approximately 5 foot
(distance from low water to
bottom of channel)
N/A – Existing
bridge has
spread
footings**
No piles anticipated
Totals 0 920 (390 below
OHWM)
NOTE No in-water pile driving will be performed as part of the Project as all potential in-water work areas will be
isolated and dewatered prior to construction commencing.
* Piling will not be entirely removed but will be cut off a minimum of 2 feet below grade and will not be visible
** A spread footing is a footing that relies on direct ground support. It is not supported on driven piles or drilled
shafts.
1032
The area where piles are to be placed will be isolated from the subject waterbody. Separation of the 1033
surface water/work area will be conducted in accordance with permit conditions for the Project and 1034
WSDOT Standard Specifications. Work below the OHWM will be conducted during the WDFW in-1035
water work window, June 15 through September 30 in each year when construction will occur. Fish 1036
exclusion will be conducted in accordance with WSDOT’s fish removal and exclusion protocols found 1037
in Appendix D of this BA. 1038
1039
All permanent piling for the Project will be either steel or concrete piling. The final piling design, 1040
including the type and size of piling, will be selected by the Contractor. Plastic piling will not be 1041
allowed by WSDOT. Untreated wood piling will only be allowed for temporary construction. Treated 1042
wood pilings will not be used. Wood piling may be abandoned and left in place on the condition that 1043
they are no longer required for ground support and are completely covered by soil or construction 1044
material in accordance with WSDOT Standard Specifications. It has not been determined if steel piles 1045
will be coated to promote preservation. If steel piles will be coated, coating will be conducted in 1046
accordance with WSDOT Standard Specifications. 1047
1048
The soil conditions in areas slated for pile driving will be determined by the Contractor after award of 1049
contract. The depth of any pile driving is dependant on soil and loading conditions. There are no 1050
known contaminated soils in areas where piling will be installed. 1051
1052
Piles will likely be installed using impact method, but the Contractor will determine the appropriate 1053
method. Sheet piles may be installed using vibratory methods, and drilled shafts may be used instead 1054
of piles. The loudest construction activities anticipated for the Project are impact pile driving of steel 1055
piles, if the Contractor elects to install steel piles. In a worst-case scenario, driving of steel piles with 1056
an impact hammer are expected to generate an Lmax averaging between 105 to 115 decibels (dBA) at 1057
50 feet from the source, and Leq levels on the order of 100 to 105 dBA at 50 feet (WSF 2000). 1058
Anticipated noise levels, and associated impacts to listed species from the Project are further discussed 1059
in Section 3 – Project Action Area and Section 5 – Species Information, Effects Analysis, and Effects 1060
Determination. 1061
1062
To minimize turbidity from pile driving, all construction activities will comply with water quality 1063
standards set forth in the Implementing Agreement (WSDOT and Ecology 1998) and the State of 1064
Washington Surface Water Quality Standards (WAC 173-201A). The current WSDOT/Ecology Water 1065
Quality Implementing Agreement allows for a mixing zone not to exceed a specified distance 1066
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 27
downstream of the Project corridor based on the characteristics of the waterbody. In the Green River, 1067
the allowable mixing zone is 300 feet downstream of the point of discharge. In addition, the 1068
Contractor will be required to follow the conditions of the TESC and SPCC Plans for the Project. The 1069
Contractor will be required to use containment structures to minimize turbidity where necessary. 1070
1071
The current design does not restrict the hours when pile driving activities could occur. However, state 1072
and local laws regulate the types and durations of noise generating activities that can occur beyond 1073
daytime hours. The Contractor will not be required to use sound attenuation devices, though will be 1074
required to obtain a noise variance for pile driving extending beyond daytime hours. No 1075
hydroacoustical monitoring is proposed for the Project. 1076
1077
If work occurs at night, the Contractor will be required to use directional lighting, to minimize the 1078
lighting that is cast on waterbodies. Within 300 feet of waters known to contain endangered species, all 1079
temporary Project lighting will be minimized between sunset and sunrise from November 1 to January 1080
15, and from March 15 to May 15. 1081
1082
2.1.4.6 Minimization Measures for Pile Driving 1083
The Contractor will adhere to the following BMPs for any pile driving activities: 1084
• All pile driving below the OHWM of any waterbody will occur during dewatered conditions. 1085
• The contractor will use vibratory driving methods to the extent possible. 1086
• Existing piling will be either removed completely or cut a minimum of 2 feet below the 1087
substrate elevation. 1088
• Excess or waste materials will not be disposed of or abandoned waterward of the OHWM or 1089
allowed to enter waters of the State. 1090
• All creosote-treated material, pile stubs, and associated sediments will be disposed of by the 1091
Contractor in a landfill that meets the liner and leachate standards of the Minimum Functional 1092
Standards, Chapter 173-304 WAC. The Contractor will provide receipts of disposal to the 1093
Project Engineer to ensure proper disposal. 1094
• Any floating debris generated during construction will be retrieved. Debris will be disposed of 1095
upland. 1096
• No creosote-treated piling will be used. 1097
• Uncured concrete will not come in contact with surface water. 1098
• Compliance with water quality restrictions imposed by Ecology (Chapter 173-201A WAC), 1099
which specifies a mixing zone beyond which water quality standards cannot be exceeded. 1100
Compliance with Ecology’s standards is intended to ensure that fish and aquatic life are 1101
protected to the extent feasible and practical. 1102
1103
2.1.5 Stormwater Treatment 1104
The conceptual stormwater treatment design includes the stormwater facilities listed below. Final 1105
design may result in changes to the proposed stormwater treatment system, but the Project will not 1106
increase pollutant concentrations discharged to receiving waterbodies. Additionally, the construction 1107
of any new stormwater facilities will be timed such that the Project meets or reduces the loading and 1108
concentration levels detailed in this BA for each stage of the Project. 1109
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 28
• Existing stormwater collection and conveyance systems will be modified as required for the 1110
new roadway geometry and as required for stormwater management using equivalent 1111
catchment areas. 1112
• Seven new flow control facilities will be constructed. Four existing facilities will be enlarged. 1113
1114
The design of stormwater facilities for this Project will comply with the design criteria and site specific 1115
concerns. The primary references for the Project’s stormwater facilities are the WSDOT HRM 1116
(WSDOT 2006a) and the Hydraulic Manual (WSDOT 2006c). 1117
1118
BMPs treating runoff from the highway will provide enhanced water quality treatment. Enhanced 1119
treatment, as defined in the HRM, provides a higher rate of removal of dissolved metals than basic 1120
treatment facilities for influent concentrations ranging from 0.003 to 0.02 mg/L for dissolved copper 1121
and 0.02 to 0.3 mg/L for dissolved zinc. Treatment facilities for local arterials will provide basic or 1122
enhanced treatment depending on the volume of traffic. The net effect of the water quality treatment 1123
will result in an improvement (decrease) of the average annual pollutant loading of TSS, total zinc, and 1124
total copper from highway pavement and local arterial improvements within the Project area. 1125
Dissolved zinc and copper annual average pollutant loading will increase; however, concentrations of 1126
TSS, total and dissolved zinc, and total and dissolved copper will improve (decrease) as a result of the 1127
built Project. 1128
1129
Stormwater will remain separated from the natural environment until it is conveyed through quality 1130
treatment facilities prior to discharge. The predominant BMP for this purpose will be ecology 1131
embankments placed adjacent to areas being widened. In some locations, a combined stormwater 1132
treatment wetland/detention pond, wet vault, or modified ecology embankments will be used to 1133
provide enhanced treatment. 1134
1135
2.1.5.1 Project Drainage Basins 1136
The Project spans three basins, listed from south to north: 1137
• Lower Green River Basin in WRIA 9 – Green Duwamish River Watershed 1138
• Black River/Springbrook Creek Basin in WRIA 9 – Green Duwamish River Watershed 1139
• Lower Cedar River Basin in WRIA 8 – Lake Washington Watershed 1140
1141
2.1.5.2 Overview of Stormwater Design Approach 1142
The design of the Project stormwater improvements will generally utilize as much of the existing 1143
drainage system as possible and provide treatment facilities that conform to accepted BMPs outlined in 1144
the design manuals. All sites selected for flow control facilities should be placed outside of the 100-1145
year floodplain. 1146
1147
Water quality BMPs will be constructed to treat 73.37 acres of new pollution generating surfaces 1148
(69.60 net acres including the removal of some existing pollution generating surfaces) plus 63.81 acres 1149
of existing pollution generating surface. BMPs treating runoff from the highway will provide 1150
enhanced water quality treatment. Treatment facilities for local arterials will provide basic or 1151
enhanced treatment depending on the volume of traffic. The net effect of the water quality treatment is 1152
an improvement of the annual pollutant concentrations from highway pavements and local arterials 1153
widened within the Project area. 1154
1155
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 29
The Project will also construct new and modify existing stormwater outfalls as follows: 1156
• One new outfall to the Green River from a new flow control facility located southwest of the 1157
new Tukwila Parkway and SR 181 intersection. It is anticipated the outfall will be located 1158
above the OHWM of the Green River; however, portions of the outfall and/or an associated 1159
armored outfall pad will occur below the OHWM. 1160
• The existing pump facilities at Springbrook Creek will be relocated. 1161
• A new outfall from the expanded flow control facility at MP 1.6 will discharge to an existing 1162
manhole associated with the existing outfall for the Springbrook Pump Station. Discharge from 1163
the expanded flow control facility will enter Springbrook Creek through an existing 24-inch-1164
diameter outlet pipe. No improvements are anticipated to this outfall to Springbrook Creek. 1165
• The existing outfall on the south side of the Cedar River is anticipated to remain in place. 1166
However, based on potential design changes, portions of the outfall and/or an associated 1167
armored outfall pad may be constructed below the OHWM. A new outfall pipe from a new 1168
spill containment vault will connect to an existing manhole next to the river. This existing 1169
manhole is part of the existing outfall system from the south spill containment pond and will 1170
remain connected to the existing Cedar River outfall. 1171
• The existing outfall on the north side of the Cedar River is also anticipated to remain in place; 1172
however, based on potential design changes, portions of the outfall and/or an associated 1173
armored outfall pad may be also constructed below the OHWM. A new outfall pipe is 1174
proposed from a reconfigured spill containment pond to an existing manhole just north of the 1175
river. The City of Renton’s storm drainage system ties in to the stormwater system at this 1176
manhole. The existing outlet pipe from this manhole discharges to the river. 1177
1178
For the purposes of this BA, it was assumed that all work below the OHWM of the Green and Cedar 1179
Rivers to construct outfalls and associated armored outfall pads would occur as part of the Project. 1180
These impacts are included in the impact numbers for the Project. 1181
1182
2.1.5.3 Water Quality Treatment 1183
Enhanced water quality BMPs will be applied for water quality treatment of the highway pavement. 1184
Local arterials widened by this Project will receive enhanced water quality BMPs or basic water 1185
quality BMPs depending on the location and volume of vehicle traffic. A minimum of 137.18 acres of 1186
new and existing pavement, or 197 percent of the new pollution generating impervious surfaces (PGIS) 1187
will be treated. Table 6 details the amount of existing PGIS in the project area, new PGIS that will 1188
created by the project, and the percentage of treatment of net new pavement area. 1189
1190
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 30
Table 6 1191
PGIS Surface Areas by Basin 1192
Basin Name
PGIS
Catchment
Area (ac)
New PGIS
Area (acres)
Net New PGIS Area
(acres)
Percent Treatment of
Net New Pavement
Area
Lower Green
River
27.17 10.93 9.31 292%
Black River/
Springbrook
Creek
90.29 50.23 48.64 186%
Lower Cedar
River
19.72 12.21 11.65 157%
Project Total 137.18 73.37 69.6 197%
1193
Tables 7, 8, and 9 detail the conceptual design for runoff treatment facilities in the Lower Green 1194
River, Black River/Springbrook Creek, and Lower Cedar River, respectively. The final design may 1195
be modified to use equivalent runoff treatment BMPs, catchment areas, or different facility 1196
locations following the WSDOT HRM and overall treated PGIS areas. Each of these tables 1197
includes the ecology embankments installed as part of the Renton Nickel Improvement Project, 1198
which will remain in place. A standard ecology embankment contains a no vegetation zone, a 1199
vegetated filter strip, and an ecology mix bed. The areas of ecology embankment shown in the 1200
tables indicate the area for ecology mix only. Additional area will be needed for the no vegetation 1201
zone and vegetated filter strip. If the water treatment facility is a modified ecology embankment, 1202
additional space will be needed for a flow spreader and filter strip. 1203
1204
Existing runoff treatment facilities along I-405 and SR 167 that treat 20 acres will be removed or 1205
altered by the road widening in the Project. Existing facilities that treat 13.21 acres will remain. 1206
This includes the ecology embankments along southbound SR 167 from MP 25.0 to MP 24.74 and 1207
the modified ecology embankment at MP 1.54 on I-405. The ecology embankments along SR 167 1208
treat 1.99 acres of existing PGIS. The modified ecology embankment treats 4.14 acres of PGIS. 1209
Mitigation for the facilities removed will be provided through additional treatment BMPs to ensure 1210
that there is no net loss of existing treatment area. 1211
1212
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 31
Table 7 1213
Runoff Treatment Facilities in the Lower Green River Basin 1214
Facility I.D. Milepost
PGIS
Catchment
Area
(acres) Facility Type
Required
Facility
Area
(square
feet)a
Required
Facility
Volume
(acre-feet)
LT G1.1.1 0.0 1.48 Modified Ecology
Embankment
3,380 N/A
LT G1.1.2 0.11 0.80 Modified Ecology
Embankment
1,800 N/A
LT G1.1.3b 0.19 1.61 Ecology
Embankment
4,150c N/A
RT G1.2.1 0.39 1.25 Modified Ecology
Embankment
2,805 N/A
LT G1.2.2 0.65 2.33 Modified Ecology
Embankment
5,325 N/A
RT G1.2.3 0.69 2.59 Modified Ecology
Embankment
5,810 N/A
RT G1.2.4 0.64 1.05 Modified Ecology
Embankment
2,340 N/A
LT G1.2.5 0.65 1.14 Ecology
Embankment
2,600 N/A
LT G1.2.6 0.77 0.98 Modified Ecology
Embankment
2,250 N/A
RT G1.2.7 0.74 1.20 Modified Ecology
Embankment
2,700 N/A
LT G1.2.8 0.90 1.19 Modified Ecology
Embankment
2,800 N/A
LT G1.2.9 0.87 0.32 Modified Ecology
Embankment
740 N/A
LT G1.2.10 0.91 7.34 Modified Ecology
Embankment
16,500 N/A
LT G1.2.11 0.91 0.30 Modified Ecology
Embankment
680 N/A
RT G1.2.12 0.88 1.24 Ecology
Embankment
2,800 N/A
RT G1.2.13 0.89 2.35 Modified Ecology
Embankment
5,250 N/A
Lower Green River
Basin Total
27.17
a The areas of ecology embankment indicate the area for ecology mix only. 1215
b Includes ecology embankments permitted as part of the Renton Nickel Improvement Project, which will remain in 1216
place. 1217
c 1,650 square feet of additional ecology embankment; 2,500 square feet permitted under the Renton Nickel 1218
Improvement Project. 1219
1220
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 32
Table 8 1221
Runoff Treatment Facilities in the Black River/ Springbrook Creek Basin 1222
Facility
I.D. Milepost
PGIS Catchment
Area (acres) Facility Type
Required Facility
Area (square feet) a
Required
Facility Volume
(acre-feet)
RT S1.1.1b 1.54 6.43 Modified Ecology
Embankment
15,700c N/A
RT S1.2.1 1.65 0.74 Modified Ecology
Embankment
1,680 N/A
LT S1.2.2 1.65 1.12 Ecology
Embankment
2,500 N/A
RT S1.2.3 1.95 7.33 Ecology
Embankment
17,900 N/A
LT S1.2.4 1.97 4.92 Ecology
Embankment
11,080 N/A
S1.2.5 2.02 1.52 Wet Pond
N/A 0.23
RT S2.1 2.20 2.02 Modified Ecology
Embankment
4,575 N/A
LT S2.2 2.27 1.25 Modified Ecology
Embankment
2,960 N/A
LT S2.3 2.44 5.30 Modified Ecology
Embankment
12,000 N/A
RT S2.4 2.50 5.25 Modified Ecology
Embankment
11,800 N/A
RT S2.6 2.71 1.16 Modified Ecology
Embankment
2,600 N/A
RT S2.7 2.74 1.74 Modified Ecology
Embankment
3,915 N/A
RT S2.8 2.83 0.89 Modified Ecology
Embankment
2,000 N/A
RT S2.9 2.90 1.43 Modified Ecology
Embankment
5,495 N/A
LT S2.10 2.97 5.06 Modified Ecology
Embankment
12,000 N/A
LT S2.11 2.99 1.70 Modified Ecology
Embankment
4,000 N/A
S2.12 (SR 167)
26.14
6.95 Modified Ecology
Embankment
16,000 N/A
LT S2.13 (SR 167)
25.81
2.83 Ecology
Embankment
6,750 N/A
RT S2.14 (SR 167)
25.86
2.86 Ecology
Embankment
6,580 N/A
S2.15 2.34 2.16 Wet Vault
N/A 0.32
RT S2.16 2.4 0.37 Modified Ecology
Embankment
900 N/A
RT S2.17 2.73 1.74 Modified Ecology
Embankment
3,880 N/A
RT S2.18 2.72 2.26 Modified Ecology
Embankment
3,862 N/A
RT S2.19 2.65 0.28 Modified Ecology
Embankment
624 N/A
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 33
Facility
I.D. Milepost
PGIS Catchment
Area (acres) Facility Type
Required Facility
Area (square feet) a
Required
Facility Volume
(acre-feet)
LT S2.20 2.83 1.73 Modified Ecology
Embankment
3,862 N/A
LT S3.1 25.48 8.49 Modified Ecology
Embankment
19,020 N/A
LT S3.2 25.22 8.04 Ecology
Embankment
18,000 N/A
RT S3.3 24.85 2.90 Ecology
Embankment
6,500 N/A
LT S3.4 b 24.94 1.59 Ecology
Embankment
4,600 N/A
LT S3.5 b 24.77 0.23 Ecology
Embankment
960 N/A
Black River/
Springbrook Creek
Basin Total
90.29
a The areas of Ecology Embankment indicate the area for ecology mix only. 1223
b Includes ecology embankments permitted as part of the Renton Nickel Improvement Project, which will remain in place. 1224
c 6,440 square feet of additional ecology embankment; 9,260 square feet permitted for the Renton Nickel Improvement Project. 1225
1226
1227
Table 9 1228
Runoff Treatment Facilities in the Lower Cedar River Basin 1229
Facility
I.D. Milepost
PGIS Catchment
Area (acres) Facility Type
Required Facility
Area (square feet) a
Required
Facility Volume
(acre-feet)
LT C1.1.1 3.1 2.06 Modified Ecology
Embankment
5,000 N/A
RT C1.1.3 3.46 2.16 Ecology
Embankment
4,950 N/A
LT C1.1.4 3.50 9.92 Modified Ecology
Embankment
22,200 N/A
LT C1.2.1 3.87 4.12 Modified Ecology
Embankment
9,214 N/A
LT C1.2.2 3.97 0.53 Modified Ecology
Embankment
1,195 N/A
LT C1.2.3 3.93 0.93 Modified Ecology
Embankment
2,181 N/A
Lower Cedar River
Basin Total
19.72
a The areas of ecology embankment indicate the area for ecology mix only. 1230
1231
2.1.5.4 Flow Control 1232
Since infiltration has been found to be infeasible due to existing soil conditions in the action area, 1233
detention ponds are the preferred flow control BMPs for the Project. Detention storage in combination 1234
with stormwater treatment wetlands or vaults may be used where appropriate. The facilities will 1235
provide a combined detention volume of 30.0 acre-feet. 1236
1237
The conceptual design shows that four existing flow control facilities constructed as part of the Renton 1238
Nickel Improvement Project will be impacted by the widening in this Project. Two detention ponds, 1239
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 34
FC G1.1 and FC S1.2, will increase in size and their outfalls will change. Detention pond FC S1.2 has 1240
been sized to detain the storm runoff generated from increased pavement that will be part of the Master 1241
Plan Improvements. The combined stormwater treatment wetland/detention pond along the west side 1242
of SR 167, FC S3.1, would be enlarged and used only for detention. The detention vault between 1243
Benson Road and I-405, FC S2.4, will have the control structure modified to handle larger flows. 1244
1245
Stormwater flow control will not be provided when discharge is made directly to the Cedar River due 1246
to its connection with Lake Washington, its designation by Ecology as a flow control-exempt 1247
waterbody, and because it is large enough that no measurable increase in hydraulic conditions and 1248
velocities will occur with increased runoff. 1249
1250
New outfalls will be constructed below the OHWM of the Green and Cedar Rivers (one in the Green 1251
River and two in the Cedar River). These new outfalls may result in increased scour and decreased 1252
available habitat in the immediate vicinity of the outfalls. The impacts from these outfalls are included 1253
in the impact numbers for the Project. 1254
1255
The base flow in the Project area is dominated by conditions in the upper watershed. In the lower 1256
Cedar River Basin, the Project proposes to increase existing impervious area by 12 acres, which is 1257
minute relative to the overall 692 square miles (442,880 acres) size, high river flow, and the low 1258
placement of the Project in this watershed. Similarly, conditions in the Green River are dominated by 1259
human activity in the upper watershed (such as land cover and operation of a dam). Groundwater in 1260
the Black River/Springbrook Creek Basin is dominated by infiltration in the Renton Hill area east of 1261
the Project. Groundwater is high in the Renton Valley and the highway widening will generally occur 1262
within areas that are steep compacted slopes, so infiltration is generally poor in the impacted areas. 1263
The effect on base flows would be negligible in each of these basins. 1264
1265
The conceptual design for detention facilities is summarized in Table 10. The locations of the 1266
proposed stormwater facilities are shown in Figure 3. 1267
1268
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 35
Table 10 1269
Major Detention Facilities for the Project 1270
Basin Facility I.D. Milepost
Net New
Impervious
Area (acres)
Catchment
Area
(acres)
Facility
Type
Volume
Required
(acre-feet) Remarks
FC G1.0 0.0 2.24 Detention
Pond 1.16
Will discharge to ditch
alongside I-5
southbound off-ramp
FC G1.1 0.2 2.06 Detention
Pond 1.35
Existing pond enlarged
from 0.47 acre-feet;
discharge to a storm
manhole, which drains
to Gilliam Creek
FC G1.2 1.0 5.28 Detention
Pond 2.75
Discharge will be to
wetland at Nelson Side
Channel utilizing the
Nelson side channel
discharge pipe cleared
in the Renton Nickel
Improvement Project
FC G1.2.1 0.75 1.20 Detention
Pond 0.65 Discharge to existing
Gilliam Creek culvert
Lower
Green River
FC G1.2.2 0.90
9.31
2.35 Detention
Pond 1.35 Discharge via a new
outfall to Green River
FC S1.2 1.6 12.80 14.02 Detention
Pond 5.55
Existing pond enlarged
from 1.84 acre-feet.
Discharge to existing
outfall from Springbrook
Creek pump station.
FC S2.1 2.28 4.95 Detention
Pond 2.23 Discharge to storm drain
in East Valley Rd
FC S2.2 2.32 10.55 Detention
Pond 4.63 Discharge to Rolling
Hills Creek cross culvert
FC S2.3 2.75 5.84 Open
Vault 2.63 Discharge to Rolling
Hills Creek
FC S2.4 3.6
27.65
6.34 Detention
Vault 2.41
Existing detention vault;
discharges to the
Thunder Hills Creek
Culvert under I-405
Black River/
Springbrook
Creek
FC S3.1 (SR 167)
25.3 8.19 10.94 Detention
Pond 5.30
Existing combined
wetland to be enlarged
to provide only flow
control; discharge will
continue to SW 23rd
Street Channel
Lower
Cedar River - 3.6 11.65 - - -
The Cedar River is listed
as a major waterbody
(flow control exempt)
Total 69.60 65.77 30.01
Figure 3
Tukwila to Renton Improvement Project
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Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 37
2.1.5.5 Proposed Conveyance Systems 1276
The proposed Project will retain many of the existing drainage structures and systems within the 1277
Project area. Closed conveyance systems will be used as the most common conveyance method along 1278
the I-405 corridor due to the commercialized surroundings. Open ditch conveyance will continue to be 1279
the preferred collection system along SR 167. Construction of the Project will require that new 1280
collection structures be added against the new edge of the roadway shoulder. These new structures 1281
will likely be connected to the existing drainage systems. In some places, such as the Cedar River 1282
discharge from the south, the roadway widening will result in new conveyance systems discharging to 1283
the waterbody. Existing conveyance will be modified as required to satisfy water quality treatment and 1284
flow control measures noted above, while maintaining existing flow patterns to each of the receiving 1285
waterbodies. 1286
1287
2.1.5.6 Method of ESA Analysis of Stormwater 1288
This BA evaluates stormwater in accordance with the BA Writers Guidance for Preparing the 1289
Stormwater Section of Biological Assessments, hereafter referred to as the “ESA Stormwater Guidance 1290
Document,” revised November 13, 2006 (WSDOT 2006b). The ESA Stormwater Guidance Document 1291
is a joint FHWA and WSDOT approach that groups projects into three levels of consultation analysis 1292
effort depending on the potential effects of the stormwater runoff associated with the Project. This BA 1293
utilizes a combination of the Level Two and a Level Three analyses. The Level Three analysis is 1294
provided only for the direct discharges in the Cedar River and Panther Creek. 1295
1296
For all portions of the Project that receive flow control, a Level Two analysis is provided. This 1297
includes all drainage basins except the Cedar River Basin and Panther Creek within the Black 1298
River/Springbrook Creek Basin. The selection of this analysis method is based on the following 1299
factors: 1300
• The Project is able to meet the no net-increase in pollutant concentration for all basins 1301
• The Project is designed to meet HRM requirements (WSDOT 2006a) and will ensure that city 1302
and county storm drainage systems do not experience increased peaks during the 100-year 1303
recurrent events 1304
• Alterations to base flow are minimal 1305
• Stormwater runoff durations will be increased 1306
1307
For the Project areas that will discharge to the Cedar River and Panther Creek without flow control, a 1308
Level Three analysis is provided. The selection of this analysis method is based on the following 1309
factors: 1310
• The Project is able to meet the no net-increase in pollutant concentration for the Cedar River 1311
Basin, although there is a moderate net-increase to pollutant loads 1312
• ESA listed aquatic species are present in the Cedar River and have the potential to be exposed 1313
to the adverse effects of the runoff treatment 1314
1315
The Project will increase the impervious area, including PGIS in the action area. However, the Project 1316
will treat an area equivalent to the new PGIS area (a net 69.60 acres) plus an additional 63.81 acres of 1317
existing PGIS area. 1318
1319
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 38
2.1.5.7 Pollutants of Concern 1320
NMFS and USFWS have asked that the following pollutants of concern be analyzed: 1321
• TSS 1322
• Dissolved and total copper 1323
• Dissolved and total zinc 1324
• Lead 1325
• Cadmium 1326
• Chromium 1327
• Polycyclic Aromatic Hydrocarbons (PAHs) 1328
1329
The load and concentration models that follow this section are only performed for TSS, total zinc, 1330
dissolved zinc, total copper, and dissolved copper. A summary of risk associated with cadmium, lead, 1331
chromium, and PAH compounds is provided in the following paragraph. In addition, Appendix F 1332
contains additional information on each of these pollutants of concern that are not included in the load 1333
and concentration models below. 1334
1335
Stormwater associated with highway runoff may contain low levels of cadmium, lead, chromium, and 1336
PAH compounds. Often, these compounds are at or below levels that can be detected with current 1337
analytical methods and may be effectively filtered or settled out in stormwater BMPs prior to being 1338
discharged to nearby waterbodies. Based on the environmental chemistry and biological fate of these 1339
compounds in an aquatic system, exposure to ESA-listed species is expected to be small. 1340
1341
Per the criteria within the ESA Stormwater Guidance Document, the highway pavement in the Project 1342
is considered to be at “high risk” due to traffic levels that exceed 60,000 Average Daily Traffic (ADT). 1343
Modeling this as a high risk project is conservative (protective) for several reasons. First, the 90th 1344
percentile effluent concentrations for treated WSDOT runoff are used to represent the expected 1345
concentrations for projects in this category. The Project, however, is proposing to utilize enhanced 1346
runoff treatment, which is expected to produce better pollutant removal. See Section 2.1.5 for 1347
additional definition of enhanced treatment. 1348
1349
2.1.5.8 Level Two Pollutant Load and Concentration Modeling – All Basins 1350
Load Model 1351
The Load Model utilizes annual pollutant loads from untreated and treated PGIS based on the 2005 1352
WSDOT NPDES Progress Report. The areas of untreated and treated PGIS are multiplied by the 1353
appropriate loading figure for both the pre-Project and post-Project conditions. 1354
1355
Concentration Model 1356
The Concentration Model utilizes expected pollutant concentrations for untreated and treated runoff 1357
based on the 2005 WSDOT NPDES Progress Report. The areas of treated and untreated impervious 1358
surfaces are multiplied by the expected pollutant concentrations for both the pre-Project and post-1359
Project conditions. These are then used to calculate the expected concentrations when the discharge 1360
from treated and untreated areas is combined for both pre-Project and post-Project conditions. 1361
1362
Summary of Load and Concentration Models 1363
The Load Model shows that the Project will result in an improvement (decrease) of the average annual 1364
pollutant loading of TSS, total zinc, and total copper from highway pavement and local arterial 1365
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 39
improvements within the Project area, no net difference in dissolved zinc. and that dissolved copper 1366
annual average pollutant loading will increase. The Concentration Model shows that concentrations of 1367
TSS, total and dissolved zinc, and total and dissolved copper will improve (decrease) as a result of the 1368
built Project. 1369
1370
The Lower Green River and Black River/Springbrook Creek Basins will experience a slight increase in 1371
pollutant load for dissolved copper and decreases in dissolved zinc. The Lower Cedar River Basin will 1372
experience increases in pollutant load for dissolved copper and dissolved zinc. Pollutant loads in all 1373
three basins for TSS, total zinc, and total copper will be reduced. The Project will also result in a net 1374
reduction in pollutant concentrations for all pollutants of concern within all basins. 1375
1376
Since the Project will result in a net reduction in pollutant concentrations for all pollutants in all basins, 1377
only the Cedar River and Panther Creek are included in the Level Three stormwater analysis in the 1378
next section due to the direct discharges associated with each. 1379
1380
Tables 11 and 12 show the results of both the Load and Concentration Models for each of the three 1381
basins. 1382
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 40
Table 11 1383
Load Calculations for Lower Green River, Black River/Springbrook Creek, 1384
and Lower Green River Basins 1385
TSS Total Zinc
Dissolved
Zinc
Total
Copper
Dissolved
Copper
Load Rates
Mean annual load from untreated surfaces
(pounds/acre) 565 1.1 0.4 0.2 0.053
Mean annual load from treated surfaces
(pounds/acre) 45 0.28 0.2 0.065 0.035
Project Total
Annual effluent load from existing
impervious surfaces prior to Project
(pounds) 113,511.35 227.38 85.95 41.81 11.67
Annual effluent load from new and existing
impervious surfaces after Project (pounds) 85,217.80 194.84 85.62 37.55 12.62
Net Change in pollutant loads between
pre- and post-Project conditions
(pounds) -28,293.55 -32.54 -0.33 -4.27 0.95
Net Change in pollutant loads between
pre- and post-Project conditions (%) -25% -14% 0% -10% 8%
Basin Breakdown
Lower Green River Basin
Annual effluent load from existing
impervious surfaces prior to Project
(pounds) 50,793.35 100.77 37.61 18.46 5.07
Annual effluent load from new and
existing impervious surfaces after Project
(pounds) 45,523.05 94.19 37.09 17.53 5.16
Net Change (pounds) -5,270.30 -6.58 -0.52 -0.93 0.09
Net Percent Change -10% -7% -1% -5% 2%
Black River/Springbrook Creek Basin
Annual effluent load from existing
impervious surfaces prior to Project
(pounds) 50,761.00 103.13 39.70 19.07 5.45
Annual effluent load from new and
existing impervious surfaces after Project
(pounds) 31,445.40 80.80 39.37 16.13 6.08
Net Change (pounds) -19,315.60 -22.33 -0.33 -2.94 0.63
Net Percent Change -38% -22% -1% -15% 12%
Lower Cedar River Basin
Annual effluent load from existing
impervious surfaces prior to Project
(pounds) 11,957.00 23.48 8.64 4.28 1.15
Annual effluent load from new and
existing impervious surfaces after Project
(pounds) 8,249.35 19.85 9.16 3.89 1.38
Net Change (pounds) -3,707.65 -3.62 0.52 -0.40 0.23
Net Percent Change -31% -15% 6% -9% 20%
1386
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 41
Table 12 1387
Concentration Calculations for Lower Green River, Black River/Springbrook Creek, 1388
and Lower Green River Basins 1389
TSS (mg/L)
Total
Zinc
(µg/L)
Dissolved
Zinc
(µg/L)
Total
Copper
(µg/L)
Dissolved
Copper
(µg/L)
Expected pollutant concentrations for
untreated runoff 192 350 110 59 14
Expected pollutant concentrations for treated
runoff 14 67 44.8 12 7.8
Project Total
Pollutant concentration for runoff pre-
Project 166.46 309.40 100.65 52.26 13.11
Pollutant concentration for runoff post-
Project 99.45 202.85 76.10 34.56 10.78
Net Change in pollutant concentration
between pre- and post-Project
conditions -67.01 -106.54 -24.55 -17.69 -2.33
Net Percent Change in pollutant
concentration -40% -34% -24% -34% -18%
Basin Breakdown
Lower Green River Basin
Pollutant concentration for runoff pre-
Project 174.38 321.99 103.55 54.35 13.39
Pollutant concentration for runoff post-
Project 144.00 273.68 92.42 46.33 12.33
Net Change -30.38 -48.30 -11.13 -8.02 -1.06
Net Percent Change -17% -15% -11% -15% -8%
Black River/Springbrook Creek Basin
Pollutant concentration for runoff pre-
Project 155.93 292.65 96.79 49.48 12.74
Pollutant concentration for runoff post-
Project 70.68 157.12 65.56 26.97 9.77
Net Change -85.25 -135.53 -31.23 -22.51 -2.97
Net Percent Change -55% -46% -32% -45% -23%
Lower Cedar River Basin
Pollutant concentration for runoff pre-
Project 183.63 336.69 106.93 56.79 13.71
Pollutant concentration for runoff post-
Project 84.82 179.60 70.74 30.70 10.27
Net Change -98.81 -157.10 -36.19 -26.09 -3.44
Net Percent Change -54% -47% -34% -46% -25%
1390
2.1.5.9 Level Three Stormwater Analysis – Lower Cedar River Basin 1391
This Level Three stormwater analysis evaluates the direct discharge of stormwater into the Cedar River 1392
and Panther Creek. 1393
1394
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 42
Existing and Proposed Treatment Chains 1395
Cedar River 1396
There are two existing spill containment ponds on either side of the Cedar River. Runoff from I-405 1397
within the Lower Cedar River Basin is piped to these ponds. These ponds are not considered to 1398
provide water quality treatment. They were designed in 1991 to meet the City of Renton’s 1399
requirement for spill containment in the Cedar River Aquifer Protection area. Each pond has a 2,000 1400
cubic foot sump for spill control and outlets designed to act as oil/water separators. The outfalls from 1401
each pond discharge to the Cedar River. 1402
1403
The conceptual level design proposes six ecology embankments to provide water quality treatment 1404
for this threshold discharge area (TDA). Runoff from a total of 19.72 acres of pollution generating 1405
impervious surfacing will be collected and treated. South of the Cedar River, two modified ecology 1406
embankments and one standard ecology embankment will be installed. A 5,000 square foot modified 1407
ecology embankment will be installed between I-405 and the southbound off ramp to SR 515. A 1408
large modified ecology embankment, covering 22,200 square feet, will be located between Main 1409
Street and I-405, just north of Cedar Ave. The standard ecology embankment will replace part of the 1410
existing shoulder along the northbound lanes of I-405 and end before the start of the northbound off 1411
ramp to SR 169. The outfalls from these three ecology embankments will be piped to a new spill 1412
containment vault that will replace the existing south pond. 1413
1414
North of the Cedar River, three modified ecology embankments are proposed. A 9,214 square foot 1415
modified ecology embankment will be located just south of the reconfigured north spill containment 1416
pond. Another 1,195 square foot modified ecology embankment will be located between Bronson 1417
Way and the southbound on-ramp to I-405. The third modified ecology embankment, 2,181 square 1418
feet in size, will be located between southbound I-405 and the southbound on-ramp from 1419
SR 169/Bronson Way. The outlets from them will be piped to the reconfigured north spill 1420
containment pond. 1421
1422
New outfalls will be constructed on both the north and south side of the Cedar River as part of the 1423
improved stormwater system. 1424
1425
The Cedar River is the only receiving water in the Project area that is documented as being exempt for 1426
flow control per WSDOT’s HRM (WSDOT 2006a). This exemption is included in the WSDOT 1427
design standard as approved by Ecology in conjunction with local jurisdictions along the Cedar River. 1428
1429
Panther Creek 1430
The proposed stormwater treatment train for Panther Creek is the same as under existing conditions. 1431
Existing stormwater treatment is provided through ecology embankments along southbound and 1432
northbound SR 167 and a stormwater treatment wetland to the west of SR 167 that were constructed 1433
for the Renton Nickel Improvement Project. Stormwater from other basins that will be routed into 1434
Panther Creek will be treated through a standard or modified ecology embankment prior to release into 1435
Panther Creek. 1436
1437
As part of the PCWRP, a direct discharge is also being proposed to the Panther Creek Wetland 1438
complex (Wetland 24.7R). A flow control exemption from Ecology will be obtained for this activity 1439
prior to construction of the PCWRP. 1440
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 43
1441
Flow Characteristics 1442
The Cedar River has characteristics that make it a good candidate for direct discharge at the I-405 1443
crossing. The Cedar River Basin consists of 184 square miles (117,760 acres). By comparison, the 1444
Project proposes to discharge stormwater from approximately 20 acres to the Cedar River. 1445
1446
Table 13 shows the existing peak flow rates for the section of river where the Project proposes direct 1447
discharge. The U.S. Geological Survey (USGS) gage is located at approximately River Mile (RM) 1.3. 1448
1449
Table 13 1450
Available Cedar River Peaks 1451
Design Storm
Recurrence Interval
Peak Flow Rate at USGS
Gage 12119000 (cfs)
2-year -
10-year 5,460
50-year 7,580
100-year 8,530
Source: FEMA Summary Report (2001) 1452
1453
Tables 14 and 15 show the discharges from the south outfall and north outfall for pre- and post-Project 1454
flows. The outfalls are located at approximately RM 1.6. 1455
1456
Table 14 1457
Peak Q from On-site Flows to Cedar River from South Outfall 1458
Design Storm
Recurrence
Interval
Pre-Project
Existing
Discharge (cfs)
Post-Project
Peak Flow
Rate (cfs)
Increase in Peak Flow
Relative to Existing
Condition (cfs)
2-year 2.7 4.3 1.6
10-year 5.4 7.6 2.2
50-year 7.3 10.8 3.5
100-year 7.4 10.8 3.4
Source: WSDOT 2006d 1459
1460
Table 15 1461
Peak Q from On-site Flows to Cedar River from North Outfall 1462
Design Storm
Recurrence
Interval
Pre-Project
Existing
Discharge (cfs)
Post-Project
Peak Flow
Rate (cfs)
Increase in Peak Flow
Relative to Existing
Condition (cfs)
2-year 5.6 6.0 0.4
10-year 8.3 9.1 0.8
50-year 12.1 13.1 1.0
100-year 13.1 14.2 1.1
Source: WSDOT 2006d 1463
1464
Table 16 shows a direct comparison of peak flows from Project outfalls for storm events. 1465
1466
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 44
Table 16 1467
Peak Flow Increase to Cedar River from Project 1468
Design
Storm
Recurrence
Interval
Increase in Peak
Flow Relative to
Existing
Condition(cfs)
Peak Flow
Rate at USGS
Gage12119000
(cfs)
Increase in Peak
Flow to Cedar River
Relative to Existing
Condition (%)
10-year 3.0 5,460 0.055%
50-year 4.5 7,580 0.059%
100-year 4.5 8,530 0.053%
1469
The developed peak outfall flows are based on the proposed Project roadway improvements and the 1470
existing outfall pipe slopes. The existing peak flows are based on the present roadway alignment and 1471
drainage system. The direct comparison of peak flows shows that the proposed increase in peak 1472
discharge is approximately six hundredths of one percent (0.06%) for storm events. Based on the 1473
relative sizes of the peak flows in the river and stormwater system, effects of increased flow are 1474
expected to be minimal. 1475
1476
Table 17 shows existing peak velocities from the 100-year storm in the Cedar River. 1477
1478
Table 17 1479
Peak Velocities From the 100-year Storm in the Cedar River 1480
Location on River
Section Area
(square feet)
Channel Width
(feet) Mean Velocity (fps)
BNSF Railroad Bridge 9,825 105 8.7
Houser Way 1,058 122 8.1
Source: FEMA Summary Report (2001) 1481
1482
As a comparison, Table 18 shows peak velocities at each outfall for pre- and post-Project for the 100-1483
year storm. 1484
1485
Table 18 1486
Peak Velocities at Each Outfall from the 100-year Storm 1487
Outfall
Pre-Project Discharge
Velocity (fps)
Post-Project Discharge
Velocity (fps)
South 7.5 8.4
North 5.5 5.7
Source: WSDOT 2006d 1488
1489
The developed peak outfall velocities are based on the proposed Project and existing outfall pipe 1490
slopes. The existing peak velocities are based on the present roadway alignment and drainage system. 1491
The direct comparison of peak velocities for the 100-year storm shows outfall velocities similar to the 1492
Cedar River peak velocities for the 100-year storm. Due to the similarities in outfall velocities, flow 1493
control effects are expected to be minimal. 1494
1495
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 45
Benefits of Direct Discharge 1496
In many smaller basins, flow control measures are needed to reduce the effect of stormwater on the 1497
hydrology of the main waterbody. Due to the size difference in storm event flows and drainage areas, 1498
investment in flow control measures would have a negligible effect on the Cedar River hydrology. 1499
1500
Direct discharge makes it cost effective to employ ecology embankments to provide enhanced runoff 1501
treatment. Ecology embankments would allow stormwater runoff to infiltrate through the ecology 1502
embankments to an enclosed stormwater system. This avoids leaving stormwater runoff in open 1503
channels where water temperatures would rise at a faster rate due to sunlight exposure and heating. 1504
Also, by avoiding the need for flow control, the residence time of stormwater in detention ponds is 1505
eliminated, along with the associated increases in water temperature. 1506
1507
Direct discharge is currently employed at the Cedar River. The Project will use the existing 1508
stormwater system with modifications to the alignment and pipe sizes. No new facilities, such as 1509
detention ponds, are required and no additional increases to the Project footprint are required for 1510
stormwater treatment in the Lower Cedar River Basin. 1511
1512
The Cedar River at the Project location is urbanized and the channel is completely engineered and 1513
constrained by levees and revetments. The outfalls will contribute (and are currently contributing) less 1514
than 1 percent of the total flow in the river on average and will discharge at similar or decreased 1515
velocities than the Cedar River. As the outfalls will contribute such a small percentage of the total 1516
flow, effects on river morphology are expected to be negligible. Investing in flow control measures 1517
would have an insignificant effect on the Cedar River morphology. 1518
1519
Outfall Details 1520
There are two existing outfalls to the main channel of the Cedar River from I-405. 1521
1522
The first outfall is a 30-inch-diameter concrete pipe located on the southern bank of the river near the 1523
BNSF Railroad bridge. The existing outlet of this pipe is above the OHWM. The inlet will be 1524
realigned to accommodate the new roadway and drainage improvements. The outfall pipe will be 1525
enlarged and extended to help reduce velocities. For the purposes of this BA, it is assumed that the 1526
new outfall and associated riprap armoring will be located below the OHWM of the Cedar River. 1527
1528
The second outfall is located across the river, on the northern bank. It is a 42-inch concrete pipe. Its 1529
existing outlet is also above the OHWM. The northern outfall will also be enlarged and extended to 1530
help reduce velocities. The modified storm drainage system will tie back into the existing system at 1531
the inlet manhole for this outfall. For the purposes of this BA, it is assumed that the new outfall and 1532
associated riprap armoring will be located below the OHWM of the Cedar River. 1533
1534
Temperature 1535
The Cedar River has no total maximum daily loads (TMDLs) currently in progress, but it is listed on 1536
Ecology’s 2004 303(d) list for exceeding temperature criterion. King County data from station X438 1537
(Cedar RM 0.2) indicate that the temperature criterion was exceeded in all years between 1998 and 1538
2002. Ecology data from monitoring station 08C070 (Cedar River at Logan Street Bridge) shows a 1539
7 day mean of daily maximum values of 19.1 degrees Celsius for mid-week August 11, 2001, and one 1540
sample beyond the criterion out of 62 samples collected between 1993 and 2001 (Ecology 2007). In 1541
addition, King County data from station A438 (Cedar River at East Jones Rd) show an overall upward 1542
trend in surface water temperatures from 1979-2004 (King County DNR 2007a). 1543
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 46
1544
Waterbodies of the State of Washington designate temperature thresholds based on the use of the 1545
waterbody, specifically by aquatic species such as salmonids because of their specific habitat 1546
requirements and dependence on ambient water conditions. The Cedar River is classified as a 1547
waterbody used by summer salmonid spawning or emergence, spawning outside of the summer season, 1548
rearing, and migration by salmonids. As such, the highest 7-day maximum temperature allowed in the 1549
river is 16 degrees Celsius (Ecology 2006). The average water temperature at the mouth of the Cedar 1550
River exceeds 16 degrees Celsius in the month of August (King County DNR 2007b). 1551
1552
Infiltration would typically be the preferred method for reducing the temperature of stormwater 1553
entering the Cedar River for several reasons, including cost and maintaining groundwater baseflow. 1554
Maintaining baseflow would be better for temperature reasons by helping to maintain cold 1555
temperatures during the warm season. However, the Project investigated infiltration options but found 1556
that they are not feasible. The Cedar River Aquifer is considered a sole source aquifer by the EPA. As 1557
such, the City of Renton does not allow infiltration within the Aquifer Protection Zone 1, which is 1558
where this area is located. 1559
1560
The Project will add 11.65 acres of impervious area within the 117,760 acre basin for an increase of 1561
approximately one hundredth of one percent (0.01%). Therefore, although baseflow will be slightly 1562
reduced by this Project, the impact is expected to be negligible. 1563
1564
The Project pavement will be a combination of new asphalt widening on grade and concrete structures. 1565
Rainfall will likely be in contact with the pavement for a very short time before draining through 1566
underground conveyance systems into the river. The infiltration of water into ecology embankments 1567
and quick conveyance into the Cedar River will minimize the amount of time for the stormwater 1568
temperature to rise. Due to the large size of the Cedar River Basin compared to the area drained by the 1569
proposed stormwater system, this temperature impact is expected to be minimal. 1570
1571
Local Stream Characteristics 1572
The portion of the Project that spans the Cedar River is located within the Renton Reach of the Cedar 1573
River. This portion of the lower Cedar River is urbanized and the stream channel is completely 1574
engineered and constrained by levees and revetments. The Renton Reach exhibits very little habitat 1575
complexity. However, it is still used as spawning grounds for Chinook salmon and steelhead trout and 1576
as a migration route for Chinook salmon, steelhead trout, and bull trout. The Renton Reach is 1577
depositional and contains high levels of fine substrates, as compared to upper reaches of the Cedar 1578
River (Kerwin 2001). Additionally, the WRIA 8 Limiting Factors Analysis identified the following 1579
limiting factors for the lower reaches of the Cedar River: 1580
• Numerous known and unknown fish passage blockages 1581
• Bank hardening features (e.g., levees) that have caused scouring and reduced side channel and 1582
off-channel habitats 1583
• Pool habitat is limited with very few deep pools, in-stream complexity and refugia habitat is 1584
lacking, and little LWD is available 1585
• The hydrologic connectivity to the floodplain has been degraded due to streambank hardening 1586
• A reduction in forest cover and increasing impervious surfaces 1587
• Riparian buffers are typically inadequate and often fragmented 1588
1589
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 47
Therefore, due to the existing in-stream and riparian conditions and proposed increases in stormwater 1590
from the Project to the Renton Reach, impacts to existing Chinook salmon, steelhead trout, and bull 1591
trout and their habitat as a result of the direct discharge are anticipated to be negligible. 1592
1593
RIV Plume Analysis 1594
For projects with a moderate increase in pollutant loading or concentration, a Level Three stormwater 1595
analysis is necessary. When the proposal involves discharge of stormwater pollutants into natural 1596
stream systems, this analysis would typically include modeling dilution using RIVPLUM5. For this 1597
report, moderate is interpreted as projected increases in either loading or concentrations of 10 percent 1598
or more above baseline conditions. 1599
1600
RIVPLUM5 is a simple spreadsheet calculation for dilution at a specified point of interest downstream 1601
from a point discharge to a river. The procedure used is described in Fischer et al., 1979 (Mixing in 1602
Inland and Coastal Waters, Academic Press) and referred to in EPA/505/2-90-001 (TSD for WQ-based 1603
Toxics Control). The calculation for dilution factors incorporates shoreline effects and has been 1604
identified by WSDOT as an appropriate tool to look at the potential stream impacts of proposed 1605
highway improvements where Level Three stormwater analyses are warranted. 1606
1607
This spreadsheet calculation is based on several assumptions, including that the discharge: 1608
• Is a single point source, which is most appropriate for single port or short diffusers, or side-1609
bank discharges 1610
• Is completely and rapidly mixed vertically, which usually only occurs in shallow rivers 1611
1612
These assumptions limit the applicability of the model and should be considered when evaluating 1613
results. Furthermore, Ecology notes that hydraulic mixing zone models such as RIVPLUM5 are only 1614
accurate to within “±40 percent.” Given these limitations, the results are considered an indicator of the 1615
likely relative effects that could result from the Project. 1616
1617
Considerations Before Running RIVPLUM5 1618
The pre- versus post-project discharge flow rate is a key input to the RIVPLUM5 analyses. The model 1619
uses the discharge flow rate into the stream along with the flow characteristics of the stream to 1620
estimate the extent and geometry of pollutant mixing downstream of the discharge. Where a project 1621
includes flow control, the discharge flows would not change and the pre- versus post-project 1622
RIVPLUM5 input would not change. The pollutant mixing characteristic would remain the same, so 1623
the RIVPLUM5 model is not generally necessary. The concentrations within the mixing zone would 1624
change as a function of the change in concentration. Since the I-405 design ensures that pre- versus 1625
post-project concentrations remain the same or are lower than existing, the affect will be an 1626
improvement in water quality throughout the mixing zone. No further analysis is necessary. 1627
1628
In the case where the project is exempt from flow control, river characteristics remain constant but the 1629
effluent (discharge) design flow would change in the proposed condition. Even if the pre- versus post-1630
project pollutant concentration model results show a reduction in pollutant concentration, RIVPLUM5 1631
would provide information to understand the effect of the changed (increased) flows and mixing zone 1632
condition in the stream. For example, in the case where effluent concentrations remain constant and 1633
exceed receiving water concentrations, as stormwater effluent increases to a greater fraction of the total 1634
volume of water in the receiving waterbody, the size of the mixing zone will also expand 1635
proportionately. Even when the relative change in volume is small and the pre- versus post-project 1636
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 48
concentration go down, there is a chance that the increased velocity of discharge flows could result in a 1637
localized increase in concentrations downstream of the project. 1638
1639
RIVPLUM5 Model 1640
The Project area includes portions of three basins: the lower Green River, Black River/Springbrook 1641
Creek, and lower Cedar River Basins. Both the Green River and Springbrook Creek are protected by 1642
flow control measures that are included with the design. The lower Green River Basin design includes 1643
conventional detention facilities. The Black River/Springbrook Creek Basin design uses either 1644
conventional detention facilities or a large wetland that is adjacent to the highway. Table 19 1645
summarizes the information that was considered to identify where moderate pollutant loading increases 1646
occur (Level Three analysis warranted) and where mixing zone characteristics could change 1647
(performing a RIVPLUM5 model warranted). 1648
1649
Table 19 1650
Background Information for Pollutant Loading and Concentration Analysis 1651
Change in Pollutant
Loading1
Change in Pollutant
Concentrations1
Basin
Dissolved
Zinc
Dissolved
Copper
Dissolved
Zinc
Dissolved
Copper
Flow
Control
Potential Change
in Mixing Zone
Characteristics?
Lower Green
River
-1% 2% -11% -8% Yes No
Black River/
Springbrook
Creek
-1% 12%2 -32% -23% Yes No
Lower Cedar
River
6% 20%2 -34% -25% No Yes
Source: I-405 Project Team, April 2007 1652
Notes: 1653
1. TSS and total metals removal are better, so they are not shown here. 1654
2. Moderate (two digit) increase in this value triggers Level 3 consideration. 1655
1656
The Cedar River is the only river or stream where there is the potential for changes in the mixing zone 1657
to result from the Project. Input for RIVPLUM5 was developed from two references: 1658
• Effluent Discharge Rate – The change in I-405 stormwater discharges to the river was 1659
estimated using WSDOT’s continuous hydrologic model, MGSFlood (WSDOT 2006d), which 1660
generates a synthetic historic record of the system. The hydrologic analysis found that the total 1661
I-405 highway 10-year peak discharge would increase from a pre-Project value of 13.8 cubic 1662
feet per second (cfs) to 16.7 cfs after the Project. 1663
• Channel Flow Characteristics – The mean monthly discharges in the Cedar River were based 1664
on USGS Gage 12119000, Renton, Washington, that has flow data from 1945 to 2006. This 1665
data shows that the mean monthly channel flows range between 1,100 cfs (for the month of 1666
January) and 191 cfs (August). This Project has followed the recent work on SR 167 by using 1667
the average mean flow rate for the February to June period. This period was required as the 1668
basis for the Puyallup River RIVPLUM5 model and is also appropriate for the Cedar River. 1669
The average flow rate of 792 cfs was calculated as input to the model. Various channel flow 1670
characteristics (such as depth, width, and velocity) were estimated using the Federal 1671
Emergency Management Agency (FEMA) 100 year floodplain flow depth and velocity. 1672
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 49
1673
Results 1674
RIVPLUM5 provides some insight into the existing mixing conditions. The mixing zone was 1675
calculated as being more than 11,000 feet downstream of the current discharge location. Since I-405 1676
crosses the Cedar River at RM 1.6, the mixing zone extends to Lake Washington. The model found 1677
that the relatively small change in I-405 discharge flow rate (3 cfs or 0.4 percent of the river flow rate) 1678
would result in the same downstream distance to completely mix and plume width boundary, but the 1679
model shows some differences in the dilution factor at points downstream. 1680
1681
The pollutant dilution is a critical element of establishing the affect of the Project, so this was 1682
investigated further for dissolved zinc and copper. 1683
1684
The pre-Project dissolved zinc concentrations from the WSDOT discharges is estimated to be 106.93 1685
micrograms per liter (µg/L). Disolved zinc concentrations will reduce to 70.74 µg/L following the 1686
Project (I-405 Team pre- versus post-Project average annual pollutant load and concentration 1687
spreadsheet, March 2007). Both of these are high compared to the 1.15 µg/L ambient dissolved zinc 1688
concentration (Metals Concentrations in Rivers and Streams Dropped from the 1994 Section 303(d) 1689
List, Ecology, January, 1995). The situation is similar for dissolved copper: the pre-Project dissolved 1690
copper concentration from the WSDOT discharges was estimated as 13.72 µg/L; the post Project 1691
discharge concentration would be 10.27 µg/L; and the ambient dissolved copper concentration is 0.27 1692
µg/L (same references). 1693
1694
The results found that the dissolved zinc and copper concentrations would be reduced throughout the 1695
downstream mixing zone as a result of the Project. RIVPLUM5 implies that the Project reduction of 1696
34 percent for dissolved zinc, combined with the added discharge flow, will maintain a decrease in 1697
concentration throughout the mixing zone, though the reduction declines from 20 percent 10 feet 1698
downstream of the outlet to 12 percent at the outlet to Lake Washington. 1699
1700
The following graphs show the general trend of concentrations as the highway discharge pollutants 1701
mix within the Cedar River. Again, RIVPLUM5 provides a basis for a general conclusion and the 1702
values could be as much as 40 percent off, so avoid looking too closely at these graphs. Flow control 1703
exemption extends the mixing zone but the overall effect is that concentrations will improve as a result 1704
of the project. 1705
1706
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 50
Mixing Zone Changes for Dissolved Zinc in the Cedar River
0.0
10.0
20.0
30.0
40.0
50.0
60.0
0 2000 4000 6000 8000 10000
Distance Downstream (ft)Concentration (ug/L)Pre-Poject
Post-Project
1707
Mixing Zone Changes for Dissolved Copper in the Cedar River
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
0 2000 4000 6000 8000 10000
Distance Downstream (ft)Concentration (ug/L)Pre-Poject
Post-Project
1708
1709
2.1.6 Fish Exclusion and Removal 1710
In-water work for the Project will occur on four waterbodies in the action area that are known or 1711
presumed to contain ESA listed species: Gilliam Creek, the Green River, Panther Creek, and the Cedar 1712
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 51
River. The approved in-water work windows for these waterbodies and known or presumed ESA 1713
species use is listed in Table 20. 1714
1715
Table 20 1716
In-Water Work Windows and Species Use 1717
Waterbody
Approved In-
water Work
Window
Known ESA
Listed Species
Use
Presumed ESA
Listed Species
Use
Gilliam Creek June 15 to
September 30
None Chinook salmon
and steelhead
trout
Green River June 15 to
September 30
Chinook salmon,
steelhead trout,
and bull trout
None
Panther Creek June 15 to
September 30
None Chinook salmon
and steelhead
trout
Cedar River June 15 to
September 30
Chinook salmon.
steelhead trout,
and bull trout
None
1718
All work below the OHWM of Gilliam Creek, the Green River, Panther Creek, and the Cedar River 1719
will be conducted during the WDFW in-water work windows listed in Table 20 unless otherwise 1720
approved during the permit process for the Project. 1721
1722
2.1.7 Summary of Project Footprint 1723
Table 21 is a summary of the amount and types of habitat that will be disturbed by the Project. 1724
1725
Table 21 1726
Area and Lineal Distance of Temporary and Permanent Disturbance to Habitat 1727
Area (square feet) of Disturbance Lineal Distance (feet) of Disturbance Habitat Types
to be Disturbed Temporary Permanent Temporary Permanent
Stream Channel 62,291 – Below OHWM
3,920 – From Shading
73,616 – Below OHWM
37,462 – From Shading
860 7,470
Riparian 39,640 293,594
Wetland 45,302 326,700
Wetland Buffer 17,860 351,094
Upland 522,036 31,528,772
1728
2.1.7.1 Disturbance to Vegetation 1729
Upland Vegetation 1730
Temporary (i.e., area will be replanted with native vegetation or hydroseeded): 1731
Square Feet: 3,192,948 Acres: 73.30 1732
1733
Permanent (i.e., area will be permanently affected by the project): 1734
Square Feet: 1,481,040 Acres: 34.00 1735
1736
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 52
Upland vegetation in the study area is classified into four land cover categories, each serving different 1737
ecological functions. The four categories are forested, shrub/grasses, maintained vegetation, and 1738
impervious surface land use cover types. The potential permanent land cover loss within the Project 1739
footprint is detailed in Table 22. 1740
1741
Table 22 1742
Potential Permanent Land Cover Loss Within the Project Footprint 1743
Land Cover
Baseline Non-impervious
Land Cover (acres)
Permanent Land Cover
Change (acres)
Percentage of Overall
Land Cover Change
(percentage)*
Forested 549.6 1.7 1%
Shrubs and Grasses 250.6 3.1 1%
Maintained Vegetation 1,550.2 29.2 2%
Total 2,350.4 34.0 1%
* Percentage of overall land cover change is shown as 1% minimum change.
1744
The forested land use cover type is defined as those vegetated areas where tree species with an average 1745
height greater than 20 feet are the predominant vegetation. Typical large tree species found in the 1746
forested portions of the study area include big leaf maple (Acer macrophyllum), red alder (Alnus rubra 1747
Bong.), black cottonwood (Populus nigra), and Douglas fir (Pseudotsuga menziesii Franco). In 1748
addition, Western red cedar (Thuja plicata) and a variety of hemlocks are occasionally found in the 1749
study area. The plants found in the understory of the forested land use cover type include immature 1750
tree species; beaked hazelnut (Corylus cornuta Marsh.); vine maple (Acer circinatum Pursh); Oregon 1751
grape (Mahonia aquifolium); salal (Gaultheria shallon Pursh); oceanspray (Holodiscus discolor); 1752
elderberry (Sambucus var.); serviceberry (Amelanchier arborea var.); stinging nettles (Urtica dioica); 1753
salmonberry (Rubus spectabilis); and sword, lady, and maidenhair ferns (Polystichum munitum, 1754
Athyrium filix-femina, and Adiantum pedatum). A variety of non-native invasive species can also be 1755
found in the forested land use cover type including black locust (Robinia pseudoacacia), American 1756
holly (Ilex opaca), English laurel (Prunus laurocerasus), field bind weed (Convolvulus arvensis), 1757
Japanese knotweed (Polygonum cuspidatum), Himalayan blackberry (Rubus discolor), and several 1758
grass, tansy, and vetch species. 1759
1760
The shrub/grasses land use cover type consists of vegetated areas predominated by woody plants less 1761
than 20 feet tall, grasses and grass-like plants, or both. Plant species typically found in this land use 1762
cover type are similar to those understory and invasive plants found in the forested land use cover type 1763
with the exception of those species that have a strong preference for shaded environments. 1764
1765
The maintained vegetation land use cover type is composed of areas of roadside vegetation, including 1766
roadway medians and shoulders, that are regularly maintained for life, health, and safety purposes, and 1767
landscaped areas consisting primarily of plants grown for beauty or ornamental value for residential, 1768
commercial, and industrial developments. Maintained vegetation is typically found in developed or 1769
disturbed areas. 1770
1771
WSDOT will prepare and implement a revegetation plan and minimize the amount of vegetation 1772
clearing to retain as many trees as practicable to minimize impacts to upland vegetation. 1773
1774
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 53
Riparian Vegetation 1775
Temporary (i.e., area will be replanted with native vegetation or hydroseeded): 1776
Square Feet: 38,796 Acres: 0.89 1777
1778
Permanent (i.e., area will be permanently affected by the project): 1779
Square Feet: 293,594 Acres: 6.74 1780
1781
Gilliam Creek, the Green River, Panther Creek, and the Cedar River are the only waterbodies in the 1782
action area that contain federally listed species and will incur impacts to their riparian buffers. 1783
Additional riparian buffer impacts stemming from construction of the Project will occur on Rolling 1784
Hills Creek, an unnamed tributary to Rolling Hills Creek, Thunder Hills Creek, and an unnamed 1785
tributary to Thunder Hills Creek. 1786
1787
Riparian buffers in the action area are highly degraded from natural conditions. They are largely 1788
dominated by non-native invasive plant species including Himalayan blackberry, reed canarygrass 1789
(Phalaris arundinacea), and Scot's broom (Cytisus scoparius). Though they do contain some native 1790
deciduous and coniferous trees and shrubs, most of the riparian trees in the Project area are immature. 1791
As the existing riparian condition of these streams are degraded, many of the functions provided by 1792
riparian vegetation, such as LWD recruitment, contribution of organic material, fish cover, bank 1793
stabilization, and stream temperature regulation are already impaired as compared to natural conditions 1794
(Kerwin 2001). 1795
1796
WSDOT will prepare and implement a revegetation plan and minimize the amount of vegetation 1797
clearing to retain as many trees as practicable to minimize impacts to riparian vegetation. 1798
1799
2.1.7.2 Disturbance to Aquatic Habitats 1800
HPAs will be required due to the in-water work proposed for the various Project stages. An HPA from 1801
WDFW for the SR 515 Project stage is anticipated on February 7, 2008. Temporary and permanent 1802
impacts to streams and wetlands are detailed below. All impacts to wetlands and streams have been 1803
rounded up to the nearest 1/100 of an acre (intervals of 436 square feet) to provide a conservative 1804
estimate of potential effects from the Project. Additional information on impacts to aquatic habitats 1805
can be found in Appendix E. 1806
1807
Wetlands 1808
Temporary: 1809
Square Feet: 45,302 Acres: 1.04 1810
1811
Table 23 summarizes the temporary wetland and wetland buffer impacts from the Project. Wetlands in 1812
the project area that are not shown in Table 23 will not incur temporary wetland or wetland buffer 1813
impacts. 1814
1815
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 54
Table 23 1816
Summary of Temporary Wetland and Wetland Buffer Effects 1817
Wetland
Wetland
Size
(acres)
Temporary
Wetland
Effects
(acres)
Percentage
of Wetland
Incurring
Temporary
Effects (%)
Wetland
Buffer
Size
(acres)
Temporary
Buffer
Effects
(acres)
Percentage of
Wetland Buffer
Incurring
Temporary
Effects (%)
0.6L 0.17 0.00 0% 0.63 0.08 13%
0.9R 1.00 0.03 3% 1.70 0.06 4%
2.2R-A 0.03 0.01 33% 0.25 0.00 0%
2.7R 0.25 0.00 0% 1.03 0.02 2%
2.82R 0.38 0.02 5% 1.22 0.02 2%
2.9L 1.05 0.03 3% 0.74 0.03 4%
24.7R 61.00* 0.83 1% 25.90 0.08 1%
25.0L 4.51 0.05 1% 3.92 0.08 2%
25.5L 11.38* 0.00 0% 4.41 0.02 1%
25.8L 11.50 0.08 1% 3.42 0.02 1%
Total 93.82* 1.04 1% 48.68 0.41 1%
* The size of these wetlands was estimated, as the majority of their area lies outside of the study area.
The total wetland acreage includes both the estimates and actual wetland survey data.
1818
In total, seven wetlands will be temporarily impacted by the Project: one Category II, four Category III 1819
and two Category IV wetlands. The total area of temporary wetland impacts is approximately 1.04 1820
acre. Only Wetlands 24.7R and 25.0L are associated with a waterbody containing ESA listed species 1821
(Panther Creek) and will experience temporary impacts of 0.83 and 0.05 acres, respectively. The 1822
remaining wetlands are not connected with a waterbody containing ESA listed species. Figures 4, 5, 1823
and 6 detail the wetlands in the Project area. 1824
1825
Temporary impacts produce short-term loss of wetland functions during construction for up to 5 years 1826
following construction. They do not, however, result in a permanent loss of wetlands after the Project 1827
is completed and once disturbed vegetation or wetland hydrology is reestablished. The extent of short-1828
term degradation will vary depending on the intensity of the temporary impact. Wetlands where the 1829
vegetation is cleared or trimmed would still retain some water quality and quantity function, although 1830
at a diminished level. Filled wetlands would provide no beneficial functions until they were restored. 1831
Wetlands temporarily impacted during construction would be restored to their pre-construction 1832
conditions following the completion of work and it is anticipated that they would return to a 1833
functioning state within 5 years. 1834
1835
Permanent (i.e., filled, hydrology permanently altered, or such a large percent of the wetland is filled 1836
that the remaining portion is non-functional): 1837
Square Feet: 326,700 Acres: 7.50 1838
1839
Table 24 summarizes the permanent wetland and wetland buffer impacts from the Project. 1840
Wetlands in the project area that are not shown in Table 24 will not incur permanent wetland or 1841
wetland buffer impacts. 1842
1843
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 55
Table 24 1844
Summary of Permanent Wetland Effects 1845
Wetland
Wetland
Size
(acres)
Permanent
Wetland
Effects
(acres)
Percentage
of Wetland
Incurring
Permanent
Effects (%)
Wetland
Buffer
Size
(acres)
Permanent
Buffer
Effects
(acres)
Percentage of
Wetland Buffer
Incurring
Permanent
Effects (%)
0.6L 0.17 0.00 0% 0.63 0.26 41%
0.9R 1.00 0.12 12% 1.70 0.64 38%
2.2R-A 0.03 0.03 100% 0.25 0.00 0%
2.2R-B 0.03 0.03 100% 0.24 0.00 0%
2.31R 0.01 0.01 100% 0.00 0.00 0%
2.6R 0.15 0.15 100% 0.49 0.00 0%
2.7R 0.25 0.00 0% 1.03 0.03 3%
2.81R 0.07 0.03 43% 0.22 0.00 0%
2.82R 0.38 0.17 45% 1.22 0.93 76%
2.9L 1.05 0.06 6% 0.74 0.12 16%
24.7R 61.00* 5.42 9% 25.90 4.23 16%
25.0L 4.51 0.61 14% 3.92 0.87 22%
25.5L 11.38* 0.00 0% 4.41 0.04 1%
25.7L 0.30 0.30 100% 0.34 0.34 100%
25.8L 11.50 0.57 5% 3.42 0.60 18%
Total 93.82* 7.50 8% 48.68 8.06 17%
* The size of these wetlands was estimated as the majority of their area lies outside of the study area.
The total wetland acreage includes both the estimates and actual wetland survey data.
1846
Twelve wetlands will be permanently impacted by the Project: one Category II, seven Category III and 1847
four Category IV wetlands. Wetlands 24.7R and 25.0L are associated with Panther Creek and will 1848
experience permanent impacts of 5.42 and 0.61 acres, respectively. 1849
1850
Permanent wetland impacts would result from the filling of wetlands to construct new facilities, 1851
diverting or re-directing surface runoff that would be necessary to support wetland hydrology, or 1852
filling such a high percentage of the area of a wetland that the remaining area would not function at 1853
pre-construction levels. 1854
1855
Mitigation will be provided to compensate for the loss of wetland resources within the Project area as 1856
per requirements of the Corps Section 404 permit and the most current versions of local critical areas 1857
regulations at the time of permitting and construction. Wetland mitigation for the Project is expected 1858
to occur at the Springbrook Bank. Mitigation will be designed to offset wetland functions lost as a 1859
result of Project impacts. 1860
1861
The current Municipal Codes of Tukwila and Renton provide wetland mitigation ratios required for 1862
disturbances or alterations to existing wetlands. The City of Tukwila’s sensitive areas code requires 1863
that projects meet a “no net loss of wetland functions and acreage” standard. Additionally, the 1864
Tukwila code requires that wetland mitigation that restores existing or creates new wetlands must 1865
compensate for impacts at a ratio of 1.5 to 1 and that wetland mitigation through enhancement of 1866
existing wetlands must compensate for impacts at a ratio of 3:1 (City of Tukwila 2007). The purpose 1867
of the City of Renton’s wetland regulations is to “ensure activities in or affecting wetlands do not 1868
threaten public safety, cause nuisances, or destroy or degrade natural wetland functions and values”; 1869
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 56
and “prevent the loss of wetland acreage and functions and strive for a net gain over present 1870
conditions” (City of Renton 2007). Additionally, the Renton Code establishes wetland mitigation 1871
ratios for wetland creation or restoration, and wetland restoration or creation plus enhancement. These 1872
mitigation ratios are shown in Tables 25 and 26. 1873
1874
Table 25 1875
City of Renton Ratios for Wetlands Creation or Restoration 1876
Wetland Category Vegetation Type Creation/Restoration Ratio
Category 1
Forested
Scrub-shrub
Emergent
6 times the area altered.
3 times the area altered.
2 times the area altered.
Category 2
Forested
Scrub-shrub
Emergent
3 times the area altered.
2 times the area altered.
1.5 times the area altered.
Category 3
Forested
Scrub-shrub
Emergent
1.5 times the area altered.
1.5 times the area altered.
1.5 times the area altered
1877
Table 26 1878
Ratios for Wetland Restoration or Creation Plus Enhancement 1879
Wetland Category Vegetation Type Restoration or Creation Ratio Enhancement Ratio
Category 1
Forested
Scrub-shrub
Emergent
3 times the area altered
1.5 times the area altered
1 times the area altered
plus
plus
plus
3.5 times the area altered
2 times the area altered
1.5 times the area altered
Category 2
Forested
Scrub-shrub
Emergent
1.5 times the area altered
1 times the area altered
1 times the area altered
plus
plus
plus
2 times the area altered
1.5 times the area altered
1 times the area altered
Category 3
Forested
Scrub-shrub
Emergent
1 times the area altered
1 times the area altered
1 times the area altered
plus
plus
plus
1 times the area altered
1 times the area altered
1 times the area altered
Figure 4
Tukwila to Renton Improvement Project
Wetlands Sheet 1
0 500 1,000
Scale in Feet
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Tukwila to Renton Improvement Project
Wetlands Sheet 2
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Scale in Feet
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24.7R
2.82R
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2.81R
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2.31R
2.81L
2.9L
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2.2R-A
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Figure 6
Tukwila to Renton Improvement Project
Wetlands Sheet 3
0 500 1,000
Scale in Feet
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2.83R
2.81R
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Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 60
Rivers and Streams 1895
Temporary (i.e., area will be dewatered or otherwise affected temporarily during project activities): 1896
Square Feet: 62,291 Acres: 1.43 1897
1898
Temporary impacts to the rivers and streams and their regulated buffers from the Project are shown in 1899
Table 27. Rivers and streams in the project area that are not shown in Table 27 will not incur 1900
temporary direct or buffer impacts. Additional information on impacts to aquatic habitats can be found 1901
in Appendix E. 1902
1903
1904
Table 27 1905
Summary of Temporary River and Stream Effects 1906
Waterbody
Regulated
Stream
Buffer
(feet)
Temporary
Effect Below
OHWM
(square feet)
Temporary
Effect to
Stream Buffer
(square feet)
Temporary
Effects from
Shading
(square feet)
Gilliam Creek 100 436 46,174 0
Green River 100 57,499 14,810 436
Panther Creek 100 3,050 6,969 0
Rolling Hills Creek 75 436 3,920 436
Unnamed tributary to Rolling Hills Creek 75 436 1,307 871
Thunder Hills Creek 75 436 4,792 0
Unnamed tributary to Thunder Hills Creek 75 436 6,970 0
Cedar River 100 0 3,049 1,845
1907
Gilliam Creek, the Green River, Panther Creek, and the Cedar River are the only waterbodies in the 1908
action area that contain federally listed species and will incur temporary impacts below the OHWM. 1909
Additional temporary impacts below the OHWM stemming from construction of the Project will occur 1910
on Rolling Hills Creek, an unnamed tributary to Rolling Hills Creek, Thunder Hills Creek, and an 1911
unnamed tributary to Thunder Hills Creek. These temporary impacts are primarily related to 1912
construction-related in-water disturbances including stream diversions, and in-stream sedimentation. 1913
Figures 7, 8, and 9 detail the streams and rivers in the Project area. 1914
1915
Figure 7
Stream Locations from I-5 to I-405
Interchange to SR-167/I-405 Interchange
Tukwila to Renton Improvement Project
0 500 1,000
Scale in Feet
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Figure 8
Stream Locations Along SR 167
Tukwila to Renton Improvement Project
0 500 1,000
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Stream Locations from SR 167/I 405
Interchange to SR 169/I 405 Interchange
Tukwila to Renton Improvement Project
0 500 1,000
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to Thunder Hills Creek
Unnamed Tributary
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Tributary to
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Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 64
Lineal Feet of Dewatering: 3,820 feet 1931
1932
Dewatering will be required to place piling within the OHWM of the Green River. Additional 1933
dewatering will be required in Panther Creek to replace the culverts that will be replaced as part of the 1934
PCWRP and, based on the fish passage decisions ultimately made for the Project, additional 1935
dewatering may be required in Gilliam Creek. The lineal feet of dewatering listed above assumes that 1936
the main channel of Panther Creek will be relocated per the PCWRP prior to any in-water impacts, and 1937
dewatering of Panther Creek is not included in the calculations of linear feet of dewatering. 1938
1939
Stream bypass/dewatering of work area 1940
The final Project design has not been determined and the method(s) used to dewater will be determined 1941
by the Contractor. The rivers and streams (or portions thereof) will be dewatered using a full diversion 1942
and a bypass flume or culvert, using a partial diversion (e.g., from shore encircling a bent of piling), 1943
using a cofferdam (e.g., isolating a bridge pier), partially dewatered (e.g., isolate a single piling); or 1944
through another means pre-approved by WSDOT. Coffer dams will not be installed with an impact 1945
driver. Coffer dams will be installed with a vibratory driver or another method as approved by 1946
WSDOT. 1947
1948
All in-water work will be performed during the approved in-water work windows for the Project. The 1949
Contractor shall also adhere to all permit conditions related to the Project. In addition, the Contractor 1950
will be required to follow the conditions of the TESC and SPCC Plans for the Project. Fish exclusion 1951
will be conducted in accordance with WSDOT’s fish removal and exclusion protocols found in 1952
Appendix D of this BA. 1953
Permanent: 1954
Square Feet: 73,616 Acres: 1.69 1955
1956
Permanent impacts to rivers and streams from the Project are shown in Table 28. Rivers and streams 1957
in the project area that are not shown in Table 28 will not incur permanent direct or buffer impacts. 1958
1959
Table 28 1960
Summary of Permanent River and Stream Effects 1961
Waterbody
Regulated
Stream
Buffer
(feet)
Permanent
Effect Below
OHWM
(square feet)
Permanent
Effect to
Stream Buffer
(square feet)
Permanent Shading
Effects from New
Over-water Cover
(square feet)
Gilliam Creek 100 1,742 46,174 0
Green River 100 16,553 121,532 16,988
Panther Creek 100 45,738 36,590 0
Rolling Hills Creek 75 4,792 33,106 5,227
Unnamed tributary to Rolling Hills Creek 75 871 12,632 871
Thunder Hills Creek 75 2,614 37,462 0
Unnamed tributary to Thunder Hills Creek 75 436 4,356 0
Cedar River 100 872 25,700 14,375
1962
The impacts shown in Table 28 are the composite summary of all impacts below the OHWM of each 1963
waterbody. Due to the overlapping nature of these impacts (e.g., bank stabilization measures and new 1964
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 65
piling in the Green River are both located in the same area), the specific impacts below the OHWM are 1965
not individually detailed. 1966
1967
Gilliam Creek, the Green River, Panther Creek, and the Cedar River are the only waterbodies in the 1968
action area that contain federally listed species and will incur permanent impacts below the OHWM. 1969
Additional permanent impacts below the OHWM stemming from construction of the Project will occur 1970
on Thunder Hills Creek, an unnamed tributary to Rolling Hills Creek, Thunder Hills Creek, and an 1971
unnamed tributary to Rolling Hills Creek. Project elements that will permanently affect rivers and 1972
streams include: 1973
• Removal of the Tukwila Parkway to I-405 northbound on-ramp north of 61st Avenue over 1974
Gilliam Creek, which will daylight a portion of the main channel of Gilliam Creek that 1975
presently flows through a culvert. Removal of the culvert and associated daylighting of 1976
Gilliam Creek will only occur if needed for Project mitigation. 1977
• Re-alignment of 66th Ave S over Gilliam Creek. The existing Christensen Road culvert will be 1978
extended. 1979
• Construction of one new bridge and reconstruction or widening of five additional bridges over 1980
the Green River to accommodate roadway widening, including installation of piling below the 1981
OHWM of the Green River. 1982
• Construction of a new stormwater outfall to the Green River. 1983
• Encroachment into the OHWM of Rolling Hills Creek to accommodate I-405, SR 167, and 1984
local roadway improvements. 1985
• Encroachment into the OHWM of Thunder Hills Creek to accommodate I-405 roadway 1986
improvements including construction of a retaining wall. 1987
• Removal of the Houser Way Bridge over the Cedar River to accommodate widening of I-405. 1988
• Reconstruction/relocation of four bridges over the Cedar River including the BNSF Railroad 1989
bridge, and a pedestrian bridge. 1990
• Removal of the existing pier within the OHWM that supports the pedestrian bridge over the 1991
Cedar River. Removal of this pier will only occur if needed for Project mitigation. 1992
• Construction of new stormwater outfalls to the Cedar River. 1993
• Encroachment into the OHWM of Panther Creek between SR 167 and East Valley Road in 1994
order to expand SR 167 to the west. 1995
• Encroachment into the OHWM of Panther Creek on the east side of SR 167 to accommodate a 1996
new SR 167 northbound auxiliary lane. 1997
• Construction of new stormwater facilities for the treatment of water quality and quantity 1998
associated with new impervious surfacing created by the Project. 1999
2000
Indirect effects due to shading: 2001
Temporary: 2002
Square Feet: 3,920 Acres: 0.09 2003
2004
Permanent: 2005
Square Feet: 37,462 Acres: 0.86 2006
2007
Temporary and permanent impacts from shading to rivers and streams are shown in Tables 27 and 28. 2008
2009
The Project will remove over-water cover over Gilliam Creek through the removal of the Tukwila 2010
Parkway on-ramp to I-405 northbound east of 61st Avenue South (if needed for Project mitigation). 2011
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 66
Conversely, the Project will create additional over-water cover on: the Green River, an unnamed 2012
tributary to Gilliam Creek, Rolling Hills Creek, an unnamed tributary to Rolling Hills Creek, Thunder 2013
Hills Creek, the Cedar River, and Panther Creek through construction of the Project elements listed 2014
above. 2015
2016
Mitigation will be provided to compensate for the loss of river and stream resources within the Project 2017
area as anticipated requirements of the Corps Section 404 permit and the WDFW HPA. Floodplain 2018
mitigation for the Project is anticipated to be performed at the Springbrook Bank; however, additional 2019
floodplain mitigation may be realized as a result of lowering the Green River Trail during construction 2020
of the new Tukwila Parkway bridge. A portion of the stream and river mitigation for the Project will 2021
be implemented through the PCWRP. Additional aquatic resources mitigation will occur on one or 2022
more waterbodies in the immediate vicinity of the Project footprint (on-site mitigation) or at an off-site 2023
location. The PCWRP is included in this BA as an element of the Project. The draft PCWRP is 2024
included as Appendix A of this BA. 2025
2026
In addition to the PCWRP, additional mitigation activities are anticipated for Project impacts that will 2027
occur in the Green and Cedar Rivers. Due to a lack of foreseeable funding for the future stages of the 2028
Project that would impact these rivers, specific mitigation activities for impacts to the Green and Cedar 2029
Rivers have not been identified or defined. All mitigation activities for impacts to the Green and Cedar 2030
Rivers will be performed directly in either the Green or Cedar Rivers (based on where the impact will 2031
occur) and will be designed to mitigate for the functions lost as a result of the Project impacts. All 2032
mitigation for impacts to the Green and Cedar Rivers will be performed in accordance with the most 2033
recent version of the local critical areas at the time of construction and will compensate for lost 2034
functions. Mitigation will be provided to compensate for the loss of stream and river resources within 2035
the Project area as per requirements of the Corps Section 404, WDFW HPA, and local permit 2036
processes. Mitigation will be designed to offset functions lost as a result of Project impacts. 2037
2038
The Cedar and Green Rivers and Springbrook Creek are designated as Shorelines of the State and are 2039
therefore regulated under the local jurisdictions shoreline management programs. 2040
2041
The portions of the Green River in the action area are regulated by the City of Tukwila. The City of 2042
Tukwila’s shoreline code (Chapter 18.44) does not contain specific provisions for mitigating impacts 2043
to shorelines of the state, but does require that all uses within the Shoreline Overlay District conform to 2044
the following general regulations: 2045
1. The use is in conformance with the regulations of the underlying zone district 2046
2. The use does not conflict with the goals and policies of the shoreline master program or the 2047
provisions of the Shoreline Act and shoreline regulations 2048
3. No structures or accessory facilities shall be located over the river unless such structure protects 2049
or promotes the public interest 2050
4. There shall be no disruption of existing trees or vegetation within the river environment unless 2051
necessary for public safety or flood control, or if allowed as a part of an approved shoreline 2052
substantial development permit 2053
5. No effluent shall be discharged into the Green River that exceeds the water quality 2054
classification as established by the State for the adjacent portion of the river 2055
6. All State and federal water quality regulations shall be strictly complied with 2056
7. Wildlife habitat in and along the river should be protected 2057
8. All perimeters of landfills or other land forms susceptible to erosion shall be provided with 2058
vegetation, retaining walls, or other satisfactory mechanisms for erosion prevention 2059
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 67
9. All necessary permits shall be obtained from federal, State, County, or municipal agencies 2060
10. No property will be acquired for public use without dedication by or just compensation to the 2061
owner 2062
11. Landfilling is prohibited within the river channel unless such landfill is determined by the 2063
Planning Commission to protect or promote the public interest 2064
12. Notwithstanding any provisions of this Code to the contrary, removal of any cottonwood tree 2065
within the river environment or the low-impact environment, which tree is 12 inches or greater 2066
in diameter as measured 4.5 feet above grade, shall be subject to the requirements of TMC 2067
Chapter 18.54, Tree Regulations 2068
2069
The portions of Springbrook Creek and the Cedar River in the action area are regulated under the City 2070
of Renton’s shoreline master program regulations. The City of Renton’s shoreline master program has 2071
both general use regulations for all shoreline uses and specific regulations for stream alteration as 2072
follows: 2073
2074
General Use Regulations for all Shoreline Uses 2075
a. Pollution and Ecological Disruption: The potential effects on water quality, water and land 2076
vegetation, water life and other wildlife (including, for example, spawning areas, migration and 2077
circulation habits, natural habitats, and feeding), soil quality and all other environmental 2078
aspects must be considered in the design plans for any activity or facility which may have 2079
detrimental effects on the environment. 2080
b. Burden on Applicant: Applicants for permits must explain the methods that will be used to 2081
abate, avoid or otherwise control the harmful effects. 2082
c. Erosion: Erosion is to be controlled through the use of vegetation rather than structural means 2083
where feasible. 2084
d. Geology: Important geological factors – such as possible slide areas – on a site must be 2085
considered. Whatever activity is planned under the application for the development permit must 2086
be safe and appropriate in view of the geological factors prevailing. 2087
2088
Use Regulations for Stream Alterations 2089
a. Definition: Stream alteration is the relocation or change in the flow of a river, stream or creek. 2090
A river, stream or creek is surface water runoff flowing in a natural or modified channel. 2091
b. Permitted Stream Alteration: 2092
i. Unless otherwise prohibited by subsection L16c of this Section, stream alteration 2093
may be allowed subject to the regulations in subsection L16d of this Section. 2094
ii. Stream alteration may be permitted if it is part of a public flood hazard 2095
reduction/habitat enhancement project approved by appropriate State and/or Federal 2096
agencies. 2097
c. Prohibited Stream Alteration: 2098
i. Stream alteration is prohibited in unique and fragile areas, except if the stream 2099
alteration is part of a public flood hazard reduction/habitat enhancement project 2100
approved by appropriate State and/or Federal agencies. 2101
ii. Stream alteration solely for the purpose of enlarging the developable portion of a 2102
parcel of land or increasing the economic potential of a parcel of land is prohibited. 2103
iii. Stream alteration is prohibited if it would be significantly detrimental to adjacent 2104
parcels. 2105
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 68
d. Regulations on Stream Alteration: 2106
i. Engineering: All proposed stream alterations shall be designed by an appropriately 2107
State licensed professional engineer. The design shall be submitted to the 2108
Development Services Division as part of the application. 2109
ii. Applicant’s Responsibility: The responsibility rests solely with the applicant to 2110
demonstrate the necessity of the proposal. 2111
iii. Timing: The timing and the methods employed will have minimal adverse effects on 2112
aquatic life. 2113
iv. Pollution: Pollution is to be minimized during and after construction. 2114
v. Low Flow Maintenance: The project must be designed so that the low flow is 2115
maintained and the escape of fish at low water is possible. 2116
vi. Over-Water Cover: No permanent over-water cover or structure shall be allowed 2117
unless it is in the public interest. 2118
2119
Non-shoreline waterbodies are regulated under the critical areas portions of the Municipal Codes of the 2120
Cities of Renton and Tukwila. The current Municipal Codes of Tukwila and Renton do not provide 2121
specific ratios for stream and river impacts but do provide guidance as to the requirements that 2122
mitigation plans must meet. 2123
2124
The City of Tukwila requires that the following performance measures be met for stream and river 2125
restoration alterations (Tukwila Code): 2126
1. Maintenance or improvement of stream channel habitat and dimensions such that the fisheries 2127
habitat functions of the compensatory stream reach meet or exceed that of the original stream 2128
2. Bank and buffer configuration should be restored to an equal or enhanced state of the original 2129
stream 2130
3. The channel, bank and buffer areas shall be replanted with native vegetation, which restores or 2131
improves the original in species, sizes and densities 2132
4. The stream channel bed and the biofiltration systems shall be equivalent to or better than in the 2133
original stream 2134
5. The original fish and wildlife habitat shall be maintained or enhanced 2135
6. Relocation of a watercourse shall not result in the new sensitive area or buffer extending 2136
beyond the development site and onto adjacent property without the agreement of the affected 2137
property owners 2138
2139
The City of Renton’s municipal code requires that mitigation meet the following requirements: 2140
The Administrator shall utilize the report “City of Renton Best Available Science Literature 2141
Review and Stream Buffer Recommendations” by AC Kindig & Company and Cedarock 2142
Consultants, dated February 27, 2003, unless superseded with a City-adopted study, to 2143
determine the existing or potential ecological function of the stream or lake or riparian habitat 2144
that is being affected. Mitigation shall address each function affected by the alteration. 2145
Mitigation to compensate alterations to stream/lake areas and associated buffers shall achieve 2146
equivalent or greater biologic and hydrologic functions and shall include mitigation for adverse 2147
impacts upstream or downstream of the development proposal site. No net loss of riparian 2148
habitat or waterbody function shall be demonstrated. 2149
2150
Other Habitat Types 2151
No other habitat types will be disturbed as a result of the Project. 2152
2153
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 69
3. Project Action Area 2154
This section describes the action area for the Tukwila to Renton Improvement Project. The action area 2155
is the defined geographic area potentially affected by the Project. For the purposes of establishing 2156
baseline conditions from which to evaluate potential effects of the Project, the types of activities to 2157
occur and physical site conditions were examined and evaluated. Project components that pose 2158
potential impacts are construction noise (including pile driving), turbidity and sedimentation resulting 2159
from construction, stormwater impacts from new impervious surfaces and construction areas, and 2160
placement of permanent structures within the OHWMs of waterbodies containing ESA listed species. 2161
2162
The action area also contains areas designated as EFH (PFMC 1999) and is in an area where 2163
environmental effects of the proposed Project may affect EFH for Chinook, coho, and pink (O. 2164
Gorbuscha) salmon (PFMC 1999). 2165
2166
Figure 10 details the action area for the Project. 2167
2168
Figure 10
Tukwila to Renton Improvement Project
Action Area
00.51
Miles
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RENTON
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r
Green RiverB l a c k R i v e r
Green RiverTrailJ:\Jobs\020107-01-I-405\project\TRIP\map_docs\TripBA\2007_06\Figure_10.mxd SMS 06/18/2007 12:02 PMAction Area
Stream
Waterbody
Trail
Park
Arterial
Freeway
Railroad
Lake Washington
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 71
In general, the action area extends 1 mile from the Project footprint. The 1 mile distance is based on 2173
the distance at which construction noise levels are expected to attenuate to background levels, as 2174
discussed in Section 3.1. However, the portion of the action area within the Cedar River also extends 2175
approximately 8,450 feet downstream of the proposed direct discharge to the confluence of the Cedar 2176
River and Lake Washington to account for the dissolved copper mixing zone from the direct discharge. 2177
Within this action area, waterbodies could be temporarily impacted during construction through in-2178
water work and associated sediment mobilization, and permanently impacted by new permanent 2179
structures placed within the OHWM and increased stormwater discharges to waterbodies containing 2180
ESA listed species. 2181
2182
3.1 Noise Considerations 2183
The Project element with the farthest reaching potential to affect endangered or threatened species is 2184
noise generated during construction, particularly installation of steel piles with an impact driver. For 2185
the purposes of this BA, the extents of the action area are based on noise effects extending 1 mile from 2186
the Project footprint. Beyond 1 mile from the Project area, construction noise levels are expected to 2187
attenuate to background levels. 2188
2189
Sound is defined as a density disturbance that propagates through a medium. In-air sound 2190
measurements are often recorded in dBA using the A-frequency weighing scale. The A-weighted 2191
rating of noise is used because it relates to human interpretation of noise. Peak sound emitted from a 2192
source is called Lmax. All sounds averaged during a measured period of time are referred to as Leq. 2193
2194
Existing noise levels were modeled using the FHWA Traffic Noise Model (TNM) at 60 locations that 2195
represent 310 residences, six parks, four trails, Renton’s Narco Property, an aquatic center, and a 2196
library (WSDOT 2007). Traffic noise is the dominant noise source in the study area, with periodic air 2197
and rail noise. Based on this modeling, existing noise level conditions in the action area range between 2198
56 and 76 dBA (WSDOT 2007). These levels range from typical suburban outdoor sound levels, 2199
between 50 to 60 dBA (EPA 1974), to very noisy levels, above 70 dBA, that are typical of locations 2200
within 100 feet of a busy freeway. 2201
2202
Noise attenuates as the distance from the source of the noise increases. In areas of hard ground cover, 2203
the standard reduction for point source noise is 6 dBA for each doubling distance from the source. For 2204
example, if sound levels were measured at 85 dBA at 50 feet from the source of the noise, at 100 feet 2205
the sound would have decreased to 79 dBA, at 200 feet it would decrease to 73 dBA, at 400 feet it 2206
would be 67 dBA, and so on. In addition, land masses, buildings, and vegetation between a noise 2207
source and the receptor can greatly reduce recorded noise levels. Freeways and buildings can reduce 2208
noise from construction by between 10 and 15 dBA, respectively (USACE and Port of Oakland 1998). 2209
Additional factors play into noise attenuation at greater distances from a noise source. Atmospheric 2210
absorption effects decrease noise levels by an additional one dBA beyond 1,000 feet (USACE and Port 2211
of Oakland 1998) and molecular absorption accounts for another 1 dBA beyond 2,000 feet (WSDOT 2212
1994). However, actual measurements taken at various Washington State Ferries terminals during pile 2213
driving activities have shown that noise can attenuate by as much as 7.8 to 9.4 dBA per doubling 2214
distance (WSDOT 1994). This is likely due to elevation changes, wind conditions, and vegetation, 2215
which accelerate noise attenuation. 2216
2217
As previously mentioned, the Project construction element with the highest potential noise level is 2218
impact pile driving, a point source noise. Point source noise is commonly measured in peak decibel 2219
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 72
levels, or the highest value of a sound pressure over a stated time interval (Harris 1991). In a worst-2220
case scenario, driving of steel piles with an impact hammer is expected to generate an Lmax of 2221
115 dBA at 50 feet from the source and Leq levels on the order of 100 to 105 dBA at 50 feet (WSF 2222
2000). 2223
2224
The sections of I-405 and SR 167 in the action area are generally surrounded by dense residential, 2225
industrial, and commercial development associated with the cities of Renton and Tukwila. Ambient 2226
conditions are consistent with urbanized areas and are characterized by heavy truck noise, helicopters, 2227
airplanes, trains, construction noise, and other human-induced noise. In addition, the existing I-405 2228
and SR 167 corridors, SR 169, and local high traffic roads such as SW Grady Way and Southcenter 2229
Boulevard, as well as frequent residential, commercial, and industrial construction, increase ambient 2230
noise levels well above 70 dBA (LaLonde 2005). Based on these considerations, 70 dBA was used as 2231
the typical background noise level for the Project. 2232
2233
Based on the attenuation rates noted above, noise rates from driving steel piles with an impact hammer 2234
would attenuate to background levels of 70 dBA between 3,200 and 6,400 feet from the source. This 2235
attenuation rate, coupled with the additional reduction in dBA from the topography and buildings 2236
surrounding the area, will result in worst-case noise impacts from driving steel piles with an impact 2237
hammer attenuating to background levels at approximately 1 mile (5,280 feet) from the source. No 2238
other noise impacts from the Project would exceed these levels; therefore, the action area encompasses 2239
a worst-case scenario for construction impacts. 2240
2241
3.2 Aquatic Considerations 2242
A RIV Plume model created for the Project shows that dissolved copper concentrations from the 2243
proposed Cedar River direct discharge will dissipate to background levels at the confluence of the 2244
Cedar River and Lake Washington. As a result, the action area includes the area within the OHWM of 2245
the Cedar River from the direct discharge location downstream approximately 8,450 feet to Lake 2246
Washington. The RIV Plume analysis for the Cedar River is discussed further in Section 2.1.5.9. All 2247
pile driving will be conducted in the dry and no other in-water impacts from sedimentation will result 2248
in an increase in the extent of the action area beyond the 1 mile radius identified under Section 3.1. 2249
2250
The Project will adhere to the terms and conditions of the Implementing Agreement (WSDOT and 2251
Ecology 1998), and WAC 173-201(A): Water Quality Standards for Surface Waters of the State of 2252
Washington. The current WSDOT/Ecology Water Quality Implementing Agreement allows for a 2253
mixing zone not to exceed a specified distance downstream of the Project corridor based on the 2254
characteristics of the waterbody. As a result of implementing the terms and conditions of these 2255
agreements, Gilliam, Rolling Hills, Thunder Hills and several unnamed creeks could be affected by 2256
sediment mobilization up to 100 feet, Panther Creek up to 200 feet, and the Green and Cedar Rivers up 2257
to 300 feet downstream of construction activities or stormwater discharges. Wetlands 24.7R and 25.0L 2258
could be affected by sediment mobilization up to 150 feet from construction activities or stormwater 2259
discharges. 2260
2261
No in-water pile driving will be performed as part of the Project as all potential in-water work areas 2262
will be isolated and dewatered prior to construction commencing. Sound waves from pile driving may 2263
be transferred through the soils surrounding the pile driving areas; however, the sound waves resulting 2264
from pile driving will be dissipated by coming into contact with a land mass prior to reaching the 2265
1 mile extent of the action area as defined above. 2266
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 73
4. Environmental Baseline 2267
The constructed Renton Nickel Improvement Project is assumed to be the environmental baseline for 2268
the purposes of this BA. 2269
2270
The Project is located in the Lower Cedar River Subarea of the Lake Washington/Cedar/Sammamish 2271
Watershed (WRIA 8) and the Lower Green River Subwatershed of the Green/Duwamish and Central 2272
Puget Sound Watershed (WRIA 9). 2273
2274
The tributaries of Lake Washington are among some of the most altered hydrological streams in the 2275
Puget Sound Region. They are typically low gradient streams, have their origins in rain-on-rain 2276
elevations, and exist in heavily urbanized settings and are subjected to the adverse habitat impacts that 2277
accompany these settings. These drainage basins generally have high levels of impervious surfaces, 2278
altered hydrologic regimes, loss of floodplain connectivity, poor riparian conditions, and water quality 2279
problems. Upstream habitat conditions show some improvement but still do not meet many of the 2280
criteria necessary for properly functioning habitats important for salmonid survival (Kerwin 2001). 2281
2282
In general, the rivers and streams in the Project action area have been highly altered from their natural 2283
states to accommodate residential, commercial, and industrial land uses. This alteration has included 2284
bank hardening, such as installing riprap and placing streams in concrete channels, reducing or 2285
removing streamside vegetation, straightening stream channels, and removing in-stream habitat. These 2286
alterations have also resulted in loss of the historic floodplains associated with most of these 2287
waterbodies. Significant changes have also occurred in the vegetation surrounding these waterbodies. 2288
What was once predominantly mature native vegetation has been replaced by a mix of immature native 2289
vegetation and non-native invasive plant species. 2290
2291
Additional information on environmental baseline conditions can be found in Appendix G – 2292
Environmental Baseline for Aquatic Habitats. 2293
2294
4.1 Site History 2295
Lower Green River (RM 11 to RM 32) 2296
Between RM 11 and 25, the Green River is believed to have formerly been a palustrine channel type, 2297
based on gradient, confinement, and descriptions of the valley bottom and soils. By 1994, virtually the 2298
entire palustrine channel segment and most of the former floodplain segment had been channelized. 2299
Today, the entire mainstem Green River in the Lower Green River sub-watershed is classified as a 2300
channelized river. Levees and revetments are common in the channelized segment between RM 11 2301
and RM 31 and present along 82 percent of the channel between RM 25.3 and RM 31.7. Levees are 2302
virtually continuous along both banks downstream of RM 25. Channelization and confinement of the 2303
channel between levees prevent high flows from accessing the floodplains, reducing groundwater 2304
recharge. Narrow, deeper channels have several negative effects to salmon habitat by: (1) producing 2305
high water velocities and bed shear stress; 2) simplifying the channel; 3) eliminating access to off-2306
channel areas; and 4) reducing availability of high flow refugia and spawning gravel stability (Kerwin 2307
2001). 2308
2309
Diversion of the White River, construction of levees and revetments, and operation of Howard Hanson 2310
Dam (HHD) have decreased the area of floodplain in the Lower Green River sub-watershed. The 2311
HHD and the levee system provide flood control, but have not fully eliminated backwatering and 2312
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 74
ponding of water in the lower watershed. Even though peak flood stages have been reduced by dam 2313
operation, the prolonged duration of moderately high flows released from reservoir storage together 2314
with confinement of these flows by levees actually raised flood stages and related backwater elevations 2315
affecting lower valley tributaries for more minor flood events (Kerwin 2001). 2316
2317
The Green River in the action area is completely contained within a dike system maintained and 2318
regulated by the Green River Flood Control Zone District. Flows are controlled by the HHD, and the 2319
river is tidally influenced at the Project area. Riparian vegetation within this reach of the Green River 2320
consists primarily of non-native invasive plant species including Himalayan blackberry, reed 2321
canarygrass, and Scot's broom, though some native deciduous and coniferous trees and shrubs are 2322
found infrequently along the river banks. The Green River lacks in-stream habitat features including 2323
LWD. Due to the condition of riparian vegetation, it also lacks opportunities for future woody debris 2324
recruitment. None of the mainstem riparian habitat in the lower Green River subwatershed is in good 2325
condition or is considered to be functioning properly based on the NMFS criteria. Also, the Green 2326
River is listed on the Ecology 303(d) list in this area for temperature, fecal coliform, and dissolved 2327
oxygen (DO). Despite its generally low habitat quality, use by Chinook salmon is documented within 2328
this reach of the Green River (Kerwin and Nelson 2000). 2329
2330
Flap gates have been installed on many of the tributaries to the Lower Green River to control 2331
backwatering that may occur during floods. The flap gates allow discharge from the tributaries to the 2332
Green River during low flow periods, but are forced shut by water pressure when the flow level of the 2333
Green River exceeds the elevation of the outlet, thereby preventing water from the Green River from 2334
flowing into the tributaries. The design of these flap gates also prevents juvenile salmonids 2335
overwintering in the lower river from accessing lower velocity off-channel habitats during flood flows 2336
(Kerwin 2001). One such flap gate is located at the confluence of Gilliam Creek and the Green River. 2337
2338
Springbrook Creek and Tributaries 2339
The Springbrook Creek subbasin is located east of the mainstem Green River, in and around the cities 2340
of Kent and Renton, Washington. The Springbrook Creek subbasin enters the mainstem Green River 2341
via the Black River at RM 11.0. With an estimated mainstem stream length of 12.0 miles, and 2342
approximately 19.1 miles of tributary streams and 3.8 miles of drainage ditches, it is the largest 2343
subbasin in the lower Green River Basin (Williams et al. 1975). 2344
2345
The Springbrook Creek subbasin drains an area of about 15,763 acres. The basin is comprised of two 2346
distinct physical settings. In the eastern half of the subbasin, rolling hills rise to elevations of about 2347
525 feet above the valley floor. In this area, the origins of stream courses are often not well defined. 2348
Slopes in the subbasin range from near 0 to 70 percent. One significant lake is present (Panther Lake) 2349
along with several smaller ponds and wetlands. Creeks originating from these upland sources drop 2350
abruptly through sharply defined steep canyons to the valley floor where stream gradients flatten 2351
quickly. Typically, these canyons are short, with high gradients and generally are not accessible to 2352
anadromous salmonids (Kerwin 2001). 2353
2354
In 1958, an earthen dam was constructed on the Black River approximately 1,000 feet upstream of the 2355
confluence with the Green River. This blocked passage of anadromous fish into Springbrook Creek. 2356
Besides impeding salmonid migration into the Springbrook Creek system, this dam blocked flows from 2357
the Green River from backwatering into the remnant Black River, which could have provided some 2358
refuge habitat for salmonids during high flows. In 1972, the U.S. Soil Conservation Service replaced 2359
the dam with the Black River Pumping Station (BRPS), which currently is operated by King County. 2360
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 75
Although it is equipped with upstream and downstream fish passage facilities, the BRPS can act as a 2361
barrier to migration of juvenile and adult salmonids due to inadequate screening, fish weir design, and 2362
operation schedule (Kerwin 2001). 2363
2364
There are several barriers along Springbrook Creek and associated tributaries. Between the SR 167 2365
crossing and Talbot Road, the creek flows through a private trout farm that presents a barrier for 2366
migrating anadromous salmonids under most stream flow conditions. Several sections of Springbrook 2367
Creek are so choked with invasive reed canarygrass and vegetation that they serve as partial barriers. 2368
If the bypass reach is dewatered, then it would also serve as a barrier to downstream migration. 2369
Upstream of the trout farm, Springbrook Creek flows through a 30-foot-long culvert and standpipe that 2370
is sloped at approximately 100 percent in the vicinity of Talbot Road. On the South Fork of 2371
Springbrook Creek, there is a concrete pad and notched weir that likely is a barrier to upstream and 2372
downstream migrating anadromous and resident fish. Water quality may serve to act as a barrier to 2373
anadromous migrating fish in the lower reaches of Mill and Springbrook Creeks (Kerwin 2001). 2374
2375
In the immediate vicinity of I-405, Springbrook Creek is largely contained within concrete walls for 2376
flood control purposes. Springbrook Creek flows under I-405 under two bridges that were constructed 2377
as part of the Renton Nickel Improvement Project. Downstream of where Springbrook Creek flows 2378
under SW Grady Way, Springbrook Creek is no longer contained in a concrete channel, but is still 2379
confined within an incised riprapped channel. 2380
2381
Riparian vegetation surrounding Springbrook Creek is a mixture of alder and willow species, 2382
Himalayan blackberry, and sedges (Carex spp.). Conifers are almost non-existent and, in those areas 2383
where shade is absent, reed canarygrass is abundant. Riparian habitat within this creek does not meet 2384
the NMFS criteria for properly functioning habitat and is a limiting factor to natural salmonid 2385
production (Kerwin 2001). 2386
2387
Springbrook Creek is listed on Ecology’s 303(d) list for exceedances of fecal coliform and DO. 2388
2389
Cedar River 2390
The reach of the Cedar River located in the action area is known as the Renton Reach. The Renton 2391
Reach is entirely artificial, is completely constrained between levees and revetments, and has been 2392
regularly dredged between 1912 and the 1970s to prevent flooding. Portions of this reach were again 2393
dredged in 1999, for the first time since the mid-1970s. This reach is essentially one long riffle with 2394
little habitat complexity. The Renton Reach is affected by urban and industrial uses along the river 2395
that contribute to local water quality problems, eliminate the potential for connection with a natural 2396
floodplain or the establishment of a riparian corridor, and prohibit significant LWD accumulations in 2397
the channel. This reach is the depositional area for many of the river's sediments, and as a result, the 2398
substrates tend to have higher levels of fine sediments than upstream substrates (King County 2399
Department of Public Works 1993). Despite its limitations, this reach of river serves as a migration 2400
route for many salmonid fishes and is used for extensive spawning and limited rearing by sockeye 2401
(Oncorhynchus nerka), Chinook, and coho (O. kisutch) salmon; steelhead and cutthroat trout (O. 2402
clarki); as well as long fin smelt (Spirinchus thaleichthys) (Kerwin and Nelson 2000). 2403
2404
Riparian vegetation is lacking within this reach of the Cedar River. In many areas along the Cedar 2405
River, development is present to the edge of the dike system. In those places, virtually no riparian 2406
vegetation is present. Where development is set back from the Cedar River, vegetation consists 2407
primarily of non-native invasive plant species including Himalayan blackberry, reed canarygrass, and 2408
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 76
Scot's broom, though some native deciduous and coniferous trees and shrubs are infrequently found 2409
along the banks (Kerwin 2001). 2410
2411
The Cedar River is on Ecology’s 303(d) list for exceedances of fecal coliform and temperature. 2412
2413
Gilliam Creek 2414
Gilliam Creek, a tributary to the Green River, has been highly modified throughout the action area. 2415
The creek is primarily contained within a straight, concrete-lined, incised, trapezoidal channel, and 2416
contains little in-stream structure. It has a narrow riparian buffer with some mature native coniferous 2417
and deciduous trees and shrubs, but the riparian buffer is dominated by non-native plant species 2418
including Himalayan blackberry, Scot's broom, and reed canarygrass. Three wetlands associated with 2419
Gilliam Creek provide limited refugia for fish during high flows and provide rearing habitat for 2420
juvenile salmonids. Flows in Gilliam Creek vary greatly with rain events due to numerous direct 2421
discharge outfalls associated with commercial and residential development in the areas surrounding the 2422
creek (Derek Koellmann, personal observation 2005). 2423
2424
Panther Creek 2425
Panther Creek is composed of two forks, hereafter referred to as the west and east forks of Panther 2426
Creek. The flow in Panther Creek past the forks is divided into the east and west forks in an 2427
approximately 2/3 to 1/3 ratio, respectively. The reach of Panther Creek immediately upstream of the 2428
east and west forks flows through a largely native, deciduous tree-dominated forest that contains some 2429
invasive species, primarily Himalayan blackberry. The stream channel in this location is connected 2430
with its floodplain (not incised) and has a large riparian buffer, but has a limited amount of in-stream 2431
cover. 2432
2433
The northerly flowing portion of the west fork of Panther Creek flows through a large patch of reed 2434
canarygrass with no other vegetation apparent. When this fork turns westerly, it flows into and 2435
through a managed bioswale until it flows into a city stormwater system under East Valley Road. The 2436
bioswale is completely vegetated with upland landscaping grasses. The west fork of Panther Creek is 2437
entirely channelized, has no native riparian canopy, and completely lacks in-stream structure. 2438
2439
The east fork of Panther Creek flows for approximately 400 feet to where it flows into a patch of reed 2440
canarygrass that is part of the Panther Creek wetland complex. Once the creek enters the patch of reed 2441
canarygrass, the creek’s main channel is no longer visible. Flow continues through the reed 2442
canarygrass patch for approximately 500 feet to where the main channel of Panther Creek becomes 2443
visible once again. The east fork of Panther Creek then flows immediately alongside SR 167 in a 2444
defined channel with a narrow, deciduous canopy to where it enters a fish ladder. 2445
2446
4.2 Upland Project Setting 2447
The upland Project setting is characterized by vegetation not associated with wetlands or aquatic 2448
habitats. Upland vegetation in the study area is divided into four land cover categories, each serving 2449
different ecological functions. The four categories are forested, shrub/grasses, maintained vegetation, 2450
and impervious surface land use cover types. 2451
2452
The forested land use cover type is defined as those vegetated areas where tree species with an average 2453
height greater than 20 feet are the predominant vegetation. Typical large tree species found in the 2454
forested portions of the study area include big leaf maple, red alder, black cottonwood, and Douglas 2455
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 77
fir. In addition, Western red cedar and a variety of hemlocks are occasionally found in the study area. 2456
The plants found in the understory of the forested land use cover type include immature tree species; 2457
beaked hazelnut; vine maple; Oregon grape; salal; oceanspray; elderberry; serviceberry; stinging 2458
nettles; salmonberry; and sword, lady, and maidenhair ferns. A variety of non-native invasive species 2459
can also be found in the forested land use cover type including black locust; American holly; English 2460
laurel; field bind weed; Japanese knotweed; Himalayan blackberry; and several grass, tansy, and vetch 2461
species. 2462
2463
The shrub/grasses land use cover type consists of vegetated areas predominated by woody plants less 2464
than 20 feet tall, grasses and grass-like plants, or both. Plant species typically found in this land use 2465
cover type are similar to those understory and invasive plants found in the forested land use cover type, 2466
with the exception of those species that have a strong preference for shaded environments. 2467
2468
The maintained vegetation land use cover type is composed of areas of roadside vegetation, including 2469
roadway medians and shoulders, that are regularly maintained for life, health, and safety purposes, and 2470
landscaped areas consisting primarily of plants grown for beauty or ornamental value for residential, 2471
commercial, and industrial developments. Maintained vegetation is typically found in developed or 2472
disturbed areas. 2473
2474
The impervious surface land use cover type includes areas such as pavement, roofs, and compacted or 2475
hardened surfaces that do not allow the passage of rainfall or runoff into the ground. Impervious 2476
surfaces such as roads, buildings, and parking lots have little to no habitat value. This cover type does 2477
contain some small patches of vegetation and open ground that might provide very limited use as 2478
habitat. This limited habitat will typically be for non-native rather than native wildlife species. 2479
2480
The associated acreages and percentages of land cover types in the study area, and typical percentages 2481
of these land cover types in the portions of the watersheds within 5 miles of the Project footprint, are 2482
listed in Table 29. 2483
2484
Table 29 2485
Baseline Land Cover In the Project Footprint 2486
Land Cover
Baseline Land
Cover in Project
Footprint
(acres)
Percentage of
Land Cover in
Project Footprint
(percent)
Typical Percentage of Land
Cover in Green River,
Springbrook, and Cedar
River Watersheds*
Forested 549.6 9% 19%
Shrubs and
Grasses 250.6 4% 6%
Maintained
Vegetation 1,550.2 27% 6%
Impervious
Surface 3,434.8 60% 46%
* - Within 5 miles of the Project footprint
2487
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 78
4.3 Physical Indicators 2488
4.3.1 Substrate 2489
In the Lower Green River Subwatershed, channelization and confinement of the channel between 2490
levees prevents high flows from accessing the floodplains, reducing groundwater recharge. Narrow, 2491
deeper channels have higher water velocity and bed shear stress, thus even small flood events may 2492
scour streambed materials (Kerwin and Nelson 2000). The HHD on the Green River effectively 2493
prevents delivery of coarse sediment from the upper basin to downstream reaches, although suspended 2494
sediment continues to be carried past the dam (Kerwin and Nelson 2000). 2495
2496
The majority of the existing mainstem Cedar River habitat has been disconnected from historic 2497
floodplains through the construction of revetments. This, in turn, results in a loss of channel habitat 2498
complexity and a reduction in the supply and stability of spawning gravels (Kerwin 2001). 2499
2500
4.3.2 Streambank Conditions 2501
Streambank conditions in the Lower Green River Subwatershed and the Lower Cedar River Subarea 2502
are not properly functioning per the NMFS Matrix of Pathways and Indicators for salmonids and 2503
functioning at unacceptable risk per the USFWS Matrix of Diagnostics/Pathways and Indicators for 2504
bull trout. 2505
2506
While there are some areas of riparian vegetation that have a width and vegetation type sufficient to 2507
maintain good bank stability, over 80 percent of the banks in the Lower Green River are comprised of 2508
levees or revetments. These structures artificially maintain bank stability and prevent erosion (Kerwin 2509
and Nelson 2000). 2510
2511
Streambank conditions in the Lower Cedar River Subarea are not well documented, and little 2512
information was found in this regard. 2513
2514
4.4 Chemical Indicators 2515
4.4.1 Water Quality 2516
4.4.1.1 Water Temperature 2517
Temperature conditions in the Lower Green River Subwatershed are not properly functioning per the 2518
NMFS Matrix of Pathways and Indicators for salmonids and functioning at unacceptable risk per the 2519
USFWS Matrix of Diagnostics/Pathways and Indicators for bull trout. The Green and Cedar Rivers 2520
are currently on the Ecology 303(d) list for exceeding allowable water quality criteria for temperature. 2521
Aside from Springbrook Creek, temperature information is not available for the remaining streams in 2522
the Project area. 2523
2524
4.4.1.2 Sediment/Turbidity 2525
Sediment/turbidity information has been identified as a data gap in the Lower Cedar River Subarea. No 2526
data were available for the duration of exposure, so it is difficult to determine the extent to which TSS 2527
is of concern (Kerwin 2001). Stream channel erosion is common in the steeper gradient portions of 2528
Panther Creek and Springbrook Creek where excess runoff from development has accelerated natural 2529
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 79
erosion processes. Sediment deposits in the lower section of Springbrook Creek have reached depths 2530
of 5 feet (Kerwin 2000). 2531
2532
4.4.1.3 Chemical Contamination/Nutrients 2533
The Green and Cedar Rivers and Springbrook Creek are included on the 2004 303(d) (Ecology 2004) 2534
list of water quality impaired waters for exceedances of criteria for fecal coliform. Additionally, the 2535
Green River and Springbrook Creek are on the 2004 303(d) list for DO. 2536
2537
Non-point sources of pollution within the Renton Reach of the Cedar River originate from developed 2538
and developing areas and include petroleum products, metals, fecal coliform, solids, and 2539
pesticides/herbicides (Kerwin 2001). The Logan Street outfall regularly discharges water with high 2540
concentrations of heavy metals (e.g. copper, lead, and zinc) that exceed acute toxicity standards. In 2541
addition, this outfall contributes high levels of suspended solids, turbidity, total phosphorus, and fecal 2542
coliform bacteria. River channel sediments are contaminated with heavy metals and petroleum 2543
hydrocarbons. Surface water discharges from the Boeing Company outfall have been shown to contain 2544
semi-volatile organics, polychlorinated biphenyls (PCBs), high levels of total phosphorus, and fecal 2545
coliforms. Semi-volatile organics (e.g., coal tar derivatives, phthalates, and PCBs) have been found in 2546
the vicinity of this outfall in river channel sediments. Outflow from the Stoneway batch plant has been 2547
shown to have high pH levels (up to 11.9). Outflow samples from the Renton Municipal Airport have 2548
been shown to contain semi-volatile organics and the herbicide 2,4-D and river sediments adjacent to 2549
the outfall have contained semi-volatile organics and PCBs (Kerwin 2001). Non-point source 2550
pollution occurring from these sources create lethal and sublethal effects to salmonids depending upon 2551
the timing of these discharges along with concentrations of these pollutants. 2552
2553
The majority of the ambient metals data in the Cedar River Subarea were collected as part of the 2554
stormwater monitoring program; therefore, baseflow metals concentrations are generally unknown 2555
(Kerwin 2001). 2556
2557
Water quality was monitored for the Black River Basin Plan from September 1991 to April 1992 2558
(Tukwila 1991). Two stations were located on Springbrook Creek and one on the Black River. These 2559
study results included elevated temperatures and low DO levels. There were also high levels of metals, 2560
fecal coliform bacteria, nutrients and turbidity during storm flows. The Black River Basin Plan 2561
indicated that under present conditions, the lack of suitable spawning habitat and questionable rearing 2562
capacity due to degraded water quality, especially during warm summer months, result in both 2563
Springbrook Creek and Panther Creek offering little in the way of fish habitat (Kerwin 2001). 2564
2565
During 2001 and 2002, a total of 18 sites were sampled by King County as part of the Green-2566
Duwamish Watershed Quality Assessment comprehensive monitoring program. Sampling sites were 2567
selected to represent various boundary conditions and land use types. Specific sampling locations 2568
within the action area of this Project include points adjacent to the Black River pumping station 2569
(representing a major stream basin), the mouth of Springbrook Creek (representing a major stream 2570
basin), Panther Creek (representing low-medium density development), and Mill Creek (Springbrook 2571
Basin) tributary (representing high density development, upstream of Springbrook Creek) (Herrera 2572
2004). 2573
2574
The Green-Duwamish Watershed Quality Assessment comprehensive monitoring program showed 2575
levels of dissolved copper reveal concentrations within the neurotoxic threshold of 2.3 to 3.0 2576
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 80
micrograms per liter (μg/L) sufficient to cause olfactory inhibition (Baldwin et al. 2003) and dissolved 2577
zinc concentrations in excess of the threshold of 5.6 μg/L for exhibiting avoidance behavior, 2578
established for juvenile rainbow trout (EPA 1980; Hansen et al. 2002a). Olfactory inhibition decreases 2579
the ability of Chinook salmon to recognize and avoid predators and navigate back to natal streams for 2580
spawning purposes, resulting in lower spawning and increased predation on Chinook. 2581
2582
4.5 Biological Conditions 2583
4.5.1 Aquatic 2584
4.5.1.1 Organic Material Recruitment 2585
Cumulatively, there is less than 1 mile of intact riparian zone comprised of medium to large mixed 2586
deciduous and coniferous trees along the lower mainstem Green River. Approximately 18 percent 2587
(12.4 miles) of the riparian zone in the Lower Green River sub-watershed supports native deciduous 2588
trees. However, in most cases, deciduous stands are narrow (less than 100 feet) or comprised of small, 2589
sparse trees mixed with patches of grass, pavement, or bare ground. Almost 50 percent of the riparian 2590
zone is comprised of forbs and grass, or shrubs, many of which are non-native (Kerwin and Nelson 2591
2000). 2592
2593
Riparian vegetation is severely lacking within the Renton Reach of the Cedar River within the action 2594
area. In many areas along the Cedar River, development is present to the edge of the dike system. In 2595
those places, virtually no riparian vegetation is present. Where development is set back from the Cedar 2596
River, vegetation consists primarily of non-native invasive plant species including Himalayan 2597
blackberry, reed canarygrass, and Scot's broom, though some native deciduous and coniferous trees 2598
and shrubs are infrequently found along the banks. 2599
2600
4.5.1.2 LWD 2601
Ninety-seven percent of the riparian zone in the lower Green River is considered to have poor LWD 2602
recruitment potential and microclimate conditions because native vegetation communities have largely 2603
been converted to grass or shrubs, and because development often extends to within 75 feet of the 2604
channel. None of the riparian zone along the lower Green River is considered to have good LWD 2605
recruitment potential (Kerwin and Nelson 2000). 2606
2607
LWD recruitment is currently rated poor along almost 100 percent of the lower Cedar River, and land 2608
use practices generally preclude active recruitment. Large amounts of LWD are removed at Landsburg 2609
Dam due to liability concerns (Kerwin 2001). 2610
2611
Stream surveys conducted for the Project found the streams and rivers in the action area to be lacking 2612
in LWD and LWD recruitment opportunities. 2613
2614
4.5.1.3 Off Channel Habitat 2615
In the Lower Green River Subwatershed, alterations in the natural flow regime during HHD refill 2616
operations may adversely impact spring spawning and incubation success by disconnecting off-channel 2617
habitats. Channelization and confinement of the channel between levees prevents high flows from 2618
accessing the floodplains, reducing groundwater recharge. Narrow, deeper channels have higher water 2619
velocity and bed shear stress, thus, even small flood events may scour bed materials. At the same time, 2620
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 81
simplification of the channel, including elimination of access to off-channel areas, reduces the 2621
availability of high flow refugia used by salmonids to escape the high velocity flows and the stability 2622
of spawning gravel (Kerwin and Nelson 2000). 2623
2624
The majority of the existing mainstem Cedar River habitat has been disconnected from historic 2625
floodplains through the construction of revetments. This, in turn, results in a loss of channel habitat 2626
complexity and a reduction in the supply and stability of spawning gravels (Kerwin 2001). The 2627
amount of available fish habitat in the lower mainstem Cedar River has been reduced by approximately 2628
56 percent due primarily to water diversion and flood control activities. The loss of off-channel 2629
rearing habitat is particularly severe for juvenile Chinook salmon. Historically, this habitat would have 2630
been utilized by juvenile Chinook salmon for rearing which, in turn, would have resulted in a larger 2631
and later timing out-migrant from the Cedar River. Because of the loss of this habitat, this life history 2632
trajectory has been reduced. This loss of habitat forces juvenile Chinook salmon to migrate as very 2633
young fry into Lake Washington, a life history trajectory that may not favor their survival (Kerwin 2634
2001). 2635
2636
4.5.1.4 Refugia 2637
Refugia conditions in the Lower Green River Subwatershed and the Lower Cedar River Subarea are 2638
not properly functioning per the NMFS Matrix of Pathways and Indicators for salmonids and 2639
functioning at unacceptable risk per the USFWS Matrix of Diagnostics/Pathways and Indicators for 2640
bull trout. 2641
2642
Adequate refugia is lacking in both watersheds; LWD, pool frequency, and off-channel habitat 2643
conditions are all not properly functioning. Existing refugia is fragmented and insufficient in size to 2644
maintain viable populations (Kerwin and Nelson 2000). 2645
2646
No changes to refugia will occur in waterbodies with ESA listed species as a result of the Project. 2647
2648
4.5.1.5 Pool Quality 2649
In the Lower Green River Subwatershed, increased fine sediment delivery from upstream reaches and 2650
urbanized tributaries is filling pools and substrate interstitial spaces, thereby reducing the amount and 2651
quality of habitat available for rearing juvenile salmonids (Kerwin and Nelson 2000). 2652
2653
The majority of the existing mainstem Cedar River habitat has been disconnected from historic 2654
floodplains through the construction of revetments. This, in turn, results in a loss of channel habitat 2655
complexity and a reduction in the supply and stability of spawning gravels (Kerwin 2001). 2656
2657
4.5.1.6 Pool Frequency 2658
In the Lower Green River Subwatershed, increased fine sediment delivery from upstream reaches and 2659
urbanized tributaries is filling pools and substrate interstitial spaces, thereby reducing the amount and 2660
quality of habitat available for rearing juvenile salmonids (Kerwin and Nelson 2000). 2661
2662
The majority of the existing mainstem Cedar River habitat has been disconnected from historic 2663
floodplains through the construction of revetments. This, in turn, results in a loss of channel habitat 2664
complexity and a reduction in the supply and stability of spawning gravels (Kerwin 2001). 2665
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 82
2666
4.5.2 Terrestrial 2667
4.5.2.1 Foraging Habitat 2668
Foraging habitat for bald eagles is typically associated with water features such as rivers, lakes, and 2669
coastal shorelines where fish, waterfowl, and seabirds are preyed upon. Bald eagle foraging is 2670
opportunistic and they feed on dead or weakened prey. Their diets include fish such as salmon, 2671
pollock, cod, rockfish, carp, dogfish, sculpin, and hake. They also feed on marine birds and their 2672
offspring, and small terrestrial mammals. They prefer high structures for perching such as trees along 2673
the shoreline, but will also use other structures such as cliffs, pilings, and open ground. They are 2674
usually seen foraging in open areas with wide views (Stalmaster and Newman 1979). 2675
2676
There are few tall trees close to the highway and few foraging opportunities in the urban development 2677
corridor along I-405 and SR 167. More suitable areas exist along the shore of Lake Washington and in 2678
the less-developed areas southeast of the Project area, toward Mount Rainier. The Lake Washington 2679
shoreline, especially on Mercer Island across the water from the Project area, provides good foraging 2680
habitat. Piling in the lake, both abandoned and part of actively used structures, furnish above-water 2681
perches in many places along the shoreline. The developed area close to the highway is of lower 2682
quality, supporting few prey mammals and lacking in suitable perching viewpoints. 2683
2684
4.5.2.2 Nesting or Roosting Habitat 2685
There are no documented bald eagle nesting or roosting sites or prey over-wintering areas within the 2686
Project action area. Nesting occurs from January 1 to August 15 (USFWS 1986). Abundant food is 2687
critical during nesting because young bald eagles are less tolerant to food deprivation than adults. Bald 2688
eagle nests are frequently associated with water, such as the Puget Sound, and most often occur close 2689
to shorelines. 2690
2691
There are few tall trees close to the highway. Eagles are not likely to use the smaller, immature trees 2692
for nesting or roosting. More suitable areas exist along the shore of Lake Washington and in the less-2693
developed areas southeast of the Project area, toward Mount Rainier. 2694
2695
4.5.2.3 Prey Over-Wintering Areas 2696
There is no known bald eagle wintering habitat in the Project action area. Wintering activities for bald 2697
eagles occur from October 31 through March 31. During the winter months, bald eagles forage, 2698
construct nests, and engage in courtship activities. There may also be bald eagles from outside the 2699
region that forage along the coastline of Puget Sound in the winter. Winter is a high-stress period for 2700
bald eagles because food is scarce and adverse weather requires the birds to expend more energy to 2701
survive. The nearest eagle territory does not extend to the Project action area boundary. 2702
2703
4.5.2.4 Perch Trees 2704
Bald eagles prefer high structures for perching such as trees along the shoreline, but will also use other 2705
structures such as cliffs, pilings, and open ground. Perch sites may be used for activities including 2706
hunting, prey consumption, signaling territory occupation, and resting. Perches are most often 2707
associated with food sources near water and will have visual access to adjacent habitats (Stalmaster 2708
and Newman 1979). Bald eagles will often choose the highest tree on the edge of a stand, selecting the 2709
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 83
strongest lateral branches. Migrating eagles could fly over the site, but are unlikely to forage or perch 2710
there due to the lack of suitable perching trees and the limited prey availability. 2711
2712
The Lake Washington shoreline, especially on Mercer Island across the water from the Project area, 2713
provides good foraging habitat. Piling in the lake, both abandoned and part of actively used structures, 2714
furnish above-water perches in many places along the shoreline. The developed area close to the 2715
highway is of lower quality, supporting few prey mammals and lacking in suitable perching 2716
viewpoints. 2717
2718
4.5.2.5 Migration Corridor 2719
The Project is located in the Western Flyway, a major bird migration corridor. As a result, eagles from 2720
outside the area may be present in the action area during winter. 2721
2722
4.5.3 Summary of USFWS and NMFS Matrix of Pathways and Indicators 2723
Tables 30 and 31 provide an overview of the environmental baseline conditions at the Project action 2724
area and watershed scales based on the USFWS and NMFS Matrix of Pathways and Indicators. For 2725
additional detail on USFWS and NMFS Matrix of Pathways and Indicators in the action area, refer to 2726
Appendix G of this BA. 2727
2728
Table 30 2729
NMFS Overview of the Environmental Baseline Conditions 2730
at the Project Action Area Scale and the Watershed Scale 2731
Baseline Environmental Conditions Effects of Project Activities
Diagnostic/Pathway
Indicators
Project Action Area
Scale Watershed Scale
Project Action
Area Scale Watershed Scale
Water Quality
Temperature
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Maintain Maintain
Sediment/Turbidity
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Maintaina Maintaina
Chemical
Contamination/Nutrients
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Maintain Maintain
Habitat Access
Physical Barriers
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Maintain Maintain
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 84
Baseline Environmental Conditions Effects of Project Activities
Diagnostic/Pathway
Indicators
Project Action Area
Scale Watershed Scale
Project Action
Area Scale Watershed Scale
Habitat Elements
Substrate Embeddedness
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Maintaina Maintaina
Large Woody Debris
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Maintain Maintain
Pool Frequency
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Maintain Maintain
Pool Quality At Risk/Functioning
at Risk
At Risk/Functioning
at Risk Maintain Maintain
Off-Channel Habitat
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Maintain Maintain
Refugia
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Maintain Maintain
Channel Conditions/Dynamics
Width/Depth Ratio
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Maintain Maintain
Streambank Condition At Risk/Functioning
at Risk
At Risk/Functioning
at Risk Maintain Maintain
Floodplain Connectivity
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Maintain Maintain
Flow/Hydrology
Change in Peak/Base
Flows
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Maintain Maintain
Increase in Drainage
Network
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Maintain Maintain
Watershed Conditions
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 85
Baseline Environmental Conditions Effects of Project Activities
Diagnostic/Pathway
Indicators
Project Action Area
Scale Watershed Scale
Project Action
Area Scale Watershed Scale
Road Density and
Location
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Degrade Maintain
Disturbance History
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Maintain Maintain
Riparian Conservation
Areas
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Not Properly
Functioning/
Functioning at
Unacceptable Risk
Maintain Maintain
a Sediment levels and substrate embeddedness will be temporarily degraded during construction; however, as a result of the
Project, they will improve to levels above current conditions.
2732
2733
Table 31 2734
USFWS Overview of Environmental Baseline Conditions 2735
at the Project Action Area Scale and the Watershed Scale 2736
Baseline Environmental Conditions Effects of Project Activities
Diagnostic/
Pathway Indicators
Project Action Area
Scale Watershed Scale
Project Action
Area Scale Watershed Scale
Subpopulation Characteristics within Subpopulation Watersheds
Subpopulation Size
There are no
documented bull trout
subpopulations in the
action area
There are no
documented bull trout
subpopulations in the
action area
Maintain Maintain
Growth and Survival
There are no
documented bull trout
subpopulations in the
action area
There are no
documented bull trout
subpopulations in the
action area
Maintain Maintain
Life History Diversity
and Isolation
There are no
documented bull trout
subpopulations in the
action area
There are no
documented bull trout
subpopulations in the
action area
Maintain Maintain
Persistence and
Genetic Integrity
There are no
documented bull trout
subpopulations in the
action area
There are no
documented bull trout
subpopulations in the
action area
Maintain Maintain
Integration of
Species and Habitat
Conditions
There are no
documented bull trout
subpopulations in the
action area
There are no
documented bull trout
subpopulations in the
action area
Maintain Maintain
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 87
5. Species Information, Effects Analysis, and Effects 2737
Determination 2738
Date obtained species list from the USFWS: 2739
2740
January 8, 2007 2741
2742
Date obtained species list from the NMFS web site: 2743
2744
January 8, 2007 2745
2746
At the time of this BA, steelhead were not listed as threatened on the NMFS website. However, based 2747
on NMFS’s March 29, 2006 proposal to list the Puget Sound DPS of steelhead as threatened under the 2748
ESA (71 Federal Register 15666), steelhead are included in Table 32. 2749
2750
Table 32 details the ESA listed species and critical habitat addressed in this BA and the associated 2751
effects determinations. 2752
2753
Table 32 2754
Species and Critical Habitat Listed Under the Federal ESA Addressed in this BA 2755
and Associated Effects Determinations 2756
Species Status Agency
Effects
Determination
Critical
Habitat
Critical Habitat
Effects
Determination
Chinook salmon
(Oncorhynchus
tshawytscha)
Threatened
(Puget Sound
ESU)
NMFS
May Affect,
Likely to
Adversely Affect
Designated
May Affect,
Likely to
Adversely Affect
Steelhead trout
(Oncorhynchus mykiss)
Threatened
(Puget Sound
ESU)
NMFS
May affect,
Likely to
adversely effect
None
designated N/A
Bull trout
(Salvelinus confluentus)
Threatened
(Coastal-Puget
Sound ESU)
USFWS
May Affect,
Likely to
Adversely Affect
Designated
May Affect,
Likely to
Adversely Affect
Bald eagle
(Haliaeetus leucocephalus) Threatened USFWS No Effect None
designated N/A
2757
An ESA Analytical Table that details individual Project components and their effects on listed species 2758
can be found in Appendix H. 2759
2760
The following species, and/or designated or proposed critical habitat, do occur, or may occur within 2761
the county this Project is located as indicated by the species list(s) but are not being addressed in this 2762
BA. No suitable habitat exists within the action area for the species listed in Table 33. Examination of 2763
the Priority Habitats and Species maps from WDFW and an analysis of habitat types in the action area 2764
showed that these species do not occur in or near the action area. Additional information on the 2765
biology of these ESA-listed species can be found in Appendix I. 2766
2767
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 88
Table 33 2768
Species Listed on the Species List but Not Addressed in this BA 2769
Species Status Agency Critical Habitat
Canada lynx
(Lynx canadensis) Threatened USFWS None in Action
Area
Gray wolf
(Canis lupus) Endangered USFWS None in Action
Area
Grizzly bear
(Ursus arctos) Threatened USFWS None in Action
Area
Marbled murrelet
(Brachyramphus marmoratus) Threatened USFWS None in Action
Area
Northern spotted owl
(Strix occidentalis caurina) Threatened USFWS None in Action
Area
Marsh sandwort
(Arenaria paludicola) Endangered USFWS None in Action
Area
Golden paintbrush
(Castilleja levisecta) Threatened USFWS None in Action
Area
Fisher
(Martes pennanti) Candidate USFWS None in Action
Area
2770
2771
5.1 NMFS-listed Species 2772
5.1.1 Chinook Salmon 2773
5.1.1.1 Status 2774
Chinook salmon are listed as threatened. 2775
Source of information pertaining to documented occurrence: 2776
1. WDFW Priority Habitat Species Data for WRIAs 8 and 9 2777
2. WRIA 8 and 9 Limiting Factors Analysis 2778
2779
5.1.1.2 Biology and Distribution in the Project Area 2780
Chinook salmon are documented as occurring in the Project area in the Green and Cedar Rivers and 2781
Springbrook Creek, which they use for spawning, rearing, migration, and foraging. Chinook salmon 2782
use is not documented in Gilliam and Panther Creeks; however, Chinook salmon are presumed to 2783
forage in Gilliam Creek due to its association with the Green River, and in the lower portions of 2784
Panther Creek due to its association with Springbrook Creek. Chinook salmon are not presumed to be 2785
present in the west fork of Panther Creek due to a reed canarygrass wetland that acts as a natural fish 2786
passage barrier downstream of the Project area (WSDOT 2005b). Except for Springbrook Creek, in-2787
water work will occur on all of these waterbodies. 2788
2789
Various life stages of Chinook salmon could be found in the waterbodies located in the action area at 2790
any time of year, and are very likely to be in the area from late summer through spring. Fall-run 2791
Chinook salmon typically spawn from late summer to late fall. Their eggs hatch in 30 to 50 days, 2792
depending on water temperature. The majority of juvenile fall Chinook salmon emerge as fry in the 2793
winter and migrate to the ocean the following spring; however, a small percentage of fall Chinook 2794
salmon follow a life history stage in which they remain in fresh water for up to 1 year. According to 2795
WDFW, fish are most abundant between October 1 and June 14. Specific life history stages of 2796
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 89
Chinook that could occur in the waterbodies in the action area are further detailed in the following 2797
paragraphs. 2798
2799
Green River 2800
Life history stages of Chinook salmon that occur in the Green River in the action area are limited to fry 2801
using the Green River for rearing or foraging, and returning adults that would pass through the action 2802
area during upstream spawning migration. The Green River in the action area does not contain any 2803
known spawning habitat. 2804
2805
Cedar River 2806
Life history stages of Chinook salmon that occur in the Cedar River in the action area include adult 2807
spawner, fry, alevin, and egg stages. Chinook salmon also use the Cedar River for foraging. 2808
2809
Observations regarding the longitudinal distribution of Chinook spawning suggest that most Chinook 2810
will consistently spawn above RM 9, with few Chinook choosing to spawn below RM 5. Peak redd 2811
counts tend to occur in RMs 14 to 18. Since 1999, no unusual aggregations of Chinook redds have 2812
been observed immediately downstream of the sockeye broodstock collection facility located at 2813
RM 6.5. Redds observed above the facility constitute 81, 96, and 91 percent of the total annual redd 2814
counts for 1999, 2000, and 2001, respectively (Burton 2003). 2815
2816
Springbrook Creek 2817
Life history stages of Chinook salmon that occur in Springbrook Creek in the action area are limited to 2818
fry using Springbrook Creek for rearing or foraging, and returning adults that would pass through the 2819
action area during upstream spawning migration. Springbrook Creek in the action area does not 2820
contain any known spawning habitat. 2821
2822
Gilliam Creek 2823
Chinook salmon use is not documented in Gilliam Creek. However, due to its association with the 2824
Green River, life history stages of Chinook salmon that could occur in Gilliam Creek in the action area 2825
are likely limited to fry that would use Gilliam Creek as an “off-channel” rearing or foraging area. 2826
2827
Panther Creek 2828
Chinook salmon use is not documented in Panther Creek; however, Chinook salmon are presumed to 2829
be present in portions of Panther Creek due to its association with Springbrook Creek. Chinook 2830
salmon are not presumed to be present in the west fork of Panther Creek due to a reed canarygrass 2831
wetland that acts as a fish passage barrier. 2832
2833
5.1.1.3 Direct and Indirect Effects 2834
Direct Effects 2835
Sediment mobilization and deposition 2836
Direct effects of sediment mobilization and deposition will occur primarily from the following 2837
activities: 2838
• Excavation 2839
• Equipment movement and activity adjacent to OHWM 2840
• Any dewatering activities. 2841
2842
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 90
This would result in increased sediment delivery into the individual creeks, streams, and out into the 2843
Green and Cedar Rivers. 2844
2845
Direct effects of sediment mobilization and deposition on Puget Sound Chinook salmon can occur 2846
during construction near surface waters. Earth disturbing activities, including excavation, stockpiling, 2847
vegetation manipulation, and construction, can result in increased delivery to streams, and increased 2848
turbidity in the water column. The severity of the effect depends on numerous factors including the 2849
proximity of the action to the water, amount of ground-disturbing activity, slope, amount of vegetation 2850
removed, and weather. Sediment introduced into streams can degrade spawning and incubation 2851
habitat, and negatively affect primary and secondary productivity. This may disrupt feeding and 2852
territorial behavior through short-term exposure to turbid water. 2853
2854
The vast majority of literature reports negative consequences from anthropogenic or naturally induced 2855
sediment regime charges. Elevated TSS conditions have been reported to cause physiological stress, 2856
reduce growth, and adversely affect fish survival. Important factors for detrimental effects of TSS on 2857
fish are the season, frequency and the duration of the exposure, not just the TSS concentration and the 2858
life stage of the species (NMFS 2005c). 2859
2860
Behavioral avoidance of turbid waters may be one of the most important effects of suspended 2861
sediments (DeVore et al. 1980; Birtwell et al. 1984; Scannell 1988). Salmonids have been observed to 2862
move laterally and downstream to avoid turbid plumes (Sigler et al. 1984; Lloyd 1987; Scannell 1988; 2863
Servizi and Martens 1991). Juvenile salmonids tend to avoid streams that are chronically turbid, such 2864
as glacial streams or those disturbed by human activities, except when the fish need to traverse these 2865
streams along migration routes (Lloyd 1987). One potentially positive effect is that turbidity can 2866
provide refuge and cover from predation, through the benefits of this effect are considered to be 2867
limited (NMFS 2006). Exposure duration is a critical determinant of the occurrence and magnitude of 2868
physical or behavioral effects. Salmonids have evolved in systems that periodically experience short-2869
type pulses (days to weeks) of high suspended sediment loads, often associated with flood events, and 2870
are adapted to such high pulse exposures. Adult and larger juvenile salmonids appear to be little 2871
affected by the high concentrations of suspended sediments that occur during storm and snowmelt 2872
runoff episodes (Bjorn and Reiser 1991). However, research indicates that chronic exposure can cause 2873
physiological stress responses that can increase maintenance energy and reduce feeding and growth 2874
(Lloyd 1987; Servizi and Martens 1991). 2875
2876
Fine sediment deposition near redds can act as a physical barrier to fry emergence (Cooper 1959, 1965; 2877
Wickett 1958; McNeil and Ahnell 1964), and McHenry et al. (1994) found that fine sediment (greater 2878
than 13 percent of sediments less than 0.85 millimeter [mm]) resulted in intragravel mortality of 2879
salmonids embryos due to oxygen stress and metabolic waste build-up. Deposited sediment can cover 2880
intragravel crevices that juvenile salmonids use for shelter, in turn decreasing the carrying capacity of 2881
streams for juvenile salmon (Cordone and Kelley 1961; Bjorn et al. 1974). 2882
2883
Fine sediment can also affect food for juvenile Puget Sound Chinook salmon. Embedded gravel and 2884
cobble reduce access to microhabitats (Brusven and Prather 1974), entombing and suffocating benthic 2885
organisms. When fine sediment is deposited on gravel and cobble, benthic species diversity and 2886
densities have been documented to drop significantly (Cordone and Pennoyer 1960; Herbert et al. 2887
1961; Bullard 1965; Reed and Elliot 1972; Nuttall and Bilby 1973; Bjorn et al. 1974; Cederholm et al. 2888
1978). Additionally, particulate materials physically abrade and mechanically disrupt respiratory 2889
structures (fish gills) and respiratory epithelia of benthic macroinvertebrates (Rand and Petrocelli 2890
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 91
1985). Reduced prey availability could reduce growth and survival of juvenile Puget Sound Chinook 2891
salmon. 2892
2893
Isolating work areas from active water flow will minimize turbidity, though the act of isolating stream 2894
flow itself can increase turbidity by suspending sediment. Commonly, reintroducing the stream to a 2895
stretch that had been dewatered to conduct work will introduce some level of turbid waters 2896
downstream. Reducing turbid water discharges can be achieved by “ramping” up the flow of surface 2897
waters through the dewatered site. 2898
2899
A portion of the studies referenced above attributed adverse affects from chronic inputs of sediments. 2900
Earth disturbing activities listed above are transitory in nature, and those that occur in-water are 2901
constrained by appropriate timing windows. In addition, diversion and bypass systems will be used to 2902
reduce the potential of turbid water discharges. As such, there is a low probability of direct mortality 2903
from turbidity associated with proposed activities because it should be localized and brief, and because 2904
the work site will be isolated from fish bearing waters during the construction period. No chronic 2905
inputs of sediment are anticipated from construction-related earth disturbance or channel alterations. 2906
2907
Pile Driving 2908
Impact driving of steel pilings can produce intense sound pressure waves that can injure and kill fish. 2909
The injuries caused by such pressure waves are known as barotraumas, and include hemorrhage and 2910
rupture of internal organs, including the swimbladder and kidneys in fish, and damage to the auditory 2911
system. Death can be instantaneous, occur within minutes after exposure, or occur several days later. 2912
Fish with swimbladders (which include salmonids) are sensitive to underwater impulsive sounds 2913
(sounds with a sharp sound pressure peak occurring in a short interval of time), because of 2914
swimbladder resonance, which is believed to occur in the frequency band of most sensitive hearing 2915
(usually 200 to 800 Hertz [Hz]). As the pressure wave passes through a fish, the swimbladder is 2916
rapidly squeezed due to the high over pressure and then rapidly expanded as the low underpressure 2917
component of the wave passes through the fish. At the high sound pressure levels (SPLs) associated 2918
with impact pile driving, the swimbladder may repeatedly expand and contract, hammering the internal 2919
organs that are held in place by the vertebral column above and the abdominal muscles and skin that 2920
hold the internal organs in place below the swimbladder. This pneumatic pounding may result in the 2921
rupture of capillaries in the internal organs as indicated by observed blood in the abdominal and 2922
maceration of kidney tissues observed during necropsies, when the pressure wave passes through the 2923
fish. Another mechanism of injury and death is “rectified diffusion,” which is the formation and 2924
growth of bubbles in tissue caused by regions of high SPL. Growth of bubbles in tissue by rectified 2925
diffusion can cause inflammation and cellular damage because of increased stress and strain, and 2926
blockage or rupture of capillaries, arteries, and veins (NMFS 2005d). NMFS has established the 2927
threshold for physical harm at 180 dBpeak for Chinook salmon (NMFS 2005d). 2928
2929
No in-water pile driving will be performed as part of the Project as all potential in-water work areas 2930
will be isolated and dewatered prior to construction commencing. WSDOT will conduct all pile 2931
driving activities in the dry (i.e., dewatered conditions) during the work window of June 15 to 2932
September 30 in each year of Project construction. 2933
2934
Vegetation Removal 2935
The constructed Project will result in a 34 acre reduction of upland vegetative cover in the action area. 2936
Of the 34 acres of vegetation that will be converted to impervious surfacing, 29.2 acres consist of 2937
maintained vegetation (ornamental landscaping and areas maintain by WSDOT for safety purposes) 2938
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 92
that provides minimal habitat values to ESA listed species. The remaining vegetation to be converted 2939
is a mix of shrubs/grasses and forested land cover types. 2940
2941
In addition to the impacts to upland vegetation, riparian vegetation will also be impacted by the 2942
Project. Removing riparian vegetation can affect fish by increasing stream temperatures, reducing the 2943
potential for LWD recruitment and for contribution of organic material for macroinvertebrates, 2944
eliminating in- and over-stream cover, and decreasing bank stability. Temporary and permanent 2945
riparian impacts will occur on eight streams and rivers within the action area including Gilliam Creek, 2946
the Green River, Panther Creek, and the Cedar River. Chinook salmon are known to be present in the 2947
Green River, Springbrook Creek, and the Cedar River and are presumed to be present in Gilliam Creek 2948
and Panther Creek in the action area. Additional riparian buffer impacts stemming from construction 2949
of the Project will occur on Rolling Hills Creek, an unnamed tributary to Thunder Hills Creek, 2950
Thunder Hills Creek, and an unnamed tributary to Rolling Hills Creek. The majority of the riparian 2951
vegetation to be removed consists of invasive plant species, native grasses and shrubs, and immature 2952
trees. Many of the functions that riparian vegetation provide are already altered and will not be 2953
substantially affected as compared to existing conditions (WSDOT 2005b). The effects to fish, if any, 2954
from riparian buffer effects related to the Project will be small in magnitude and indiscernible, 2955
particularly considering the already degraded condition of the existing riparian buffer (WSDOT 2956
2005b). 2957
2958
WSDOT will prepare and implement a revegetation plan and minimize the amount of vegetation 2959
clearing to retain as many trees as practicable to minimize impacts to upland vegetation. WSDOT will 2960
also provide compensatory mitigation for all stream and buffer/riparian impacts in accordance with 2961
applicable local, state, and federal regulations in place at the time of permitting. Mitigation will be 2962
designed to offset functions lost as a result of Project impacts. 2963
2964
Stormwater 2965
The Project would add approximately 69.60 net acres of new impervious surface within the study area. 2966
2967
Stormwater runoff from roads in urban areas can convey pollutants at concentrations that are toxic to 2968
fish (Spence et al. 1996). The relative success of removing pollutants from stormwater runoff of roads 2969
is dependent upon the treatment technology utilized, and maintenance of treatment facilities. Studies 2970
have indicated a large degree of variability among different treatment applications (Schueler 1987; 2971
Hayes et al. 1996; Young et al. 1996). Pollutants associated with road runoff can affect the 2972
physiological or behavioral performance of salmonids in ways that reduce growth and survival, 2973
migratory success, and/or reproduction. The effects of roadway pollutant can be exacerbated by poor 2974
water quality conditions and other pollutants delivered through non-roadway mechanisms (such as 2975
pesticide runoff). In order to minimize effects from increase of TSS, total copper, and zinc to Chinook 2976
salmon, WSDOT will ensure that stormwater treatment facilities within the action area will achieve a 2977
no net increase in pollutant concentrations of TSS, total and dissolved copper, and total and dissolved 2978
zinc for any stormwater effluent that discharges to the Green River, Springbrook Creek, the Cedar 2979
River, and their tributaries. 2980
2981
Increases in stream peak flows resulting from increased impervious area can negatively affect fish. 2982
Peak flows and sustained high flows in streams during storm events can cause harm to, or kill, fish. 2983
Harm typically occurs when fish or other aquatic species are unable to get out of high flow areas and 2984
are swept downstream or battered against rocks or streambanks. In urbanized streams where little to 2985
no refugia habitat exists and where storm events can cause rapid rises in stream levels, peak or 2986
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 93
sustained high flows can be especially detrimental to fish. Rerouting of stormwater into new or 2987
existing stormwater systems can change baseline drainage patterns into or away from creeks, and can 2988
also result in lost opportunities for groundwater infiltration. 2989
2990
In addition to effects on fish, increases in stream peak flows can also negatively affect aquatic habitat. 2991
High flows can cause streambanks and streambeds to scour and erode resulting in increased 2992
sedimentation, changes in streambed composition, and decreased habitat complexity. Streambank 2993
scour can also result in losses of riparian buffers as streambanks erode and cause plants to fall into the 2994
water. Negative effects on stream hydrology are expected to be minimized by the following factors: 2995
WSDOT will provide flow control for runoff from new impervious area to address changes in 2996
stormwater discharge to streams except for the direct discharge proposed for the Cedar River. 2997
Stormwater flow control facilities will be designed in accordance with the WSDOT HRM (WSDOT 2998
2006a). 2999
3000
The WSDOT HRM mandates that the duration and magnitude of stormwater discharge into streams 3001
and rivers during storms will be generally equal to or less than that experienced under existing 3002
conditions for the full range of design, from 50 percent of the 2-year through to the 50-year recurrent 3003
storm events. 3004
3005
The stormwater facilities that will be constructed as part of the Project are intended to mitigate any 3006
flow effects that the new pavement will have on peak flows within the study area. Likewise, no 3007
negative effects to stream base flows are likely to occur from the increase in impervious surface, as the 3008
overall amount of impervious surface resulting from the Project will only slightly increase the total 3009
percentage of impervious surface in the watersheds where the Project is located. 3010
3011
New storm drainage systems will collect runoff from an area greater than all new impervious surfaces 3012
created by the Project. New stormwater features will improve water quality of stormwater runoff 3013
before discharging it into streams or rivers. Enhanced runoff treatment BMPs will be used for 3014
roadways with 30,000 or greater ADT as required by the HRM. Stormwater discharges to the streams 3015
and rivers of the study area would comply with water quality regulations in accordance with the 3016
WSDOT HRM. Additionally, concentrations of TSS, total copper and zinc, and dissolved copper and 3017
zinc will be reduced in each of the three drainage basins, as detailed in Section 2.1.5 of this BA. 3018
Therefore, the water quality of stormwater discharge associated with the Project is not expected to 3019
adversely affect Chinook salmon. 3020
3021
New outfalls will be constructed below the OHWM of the Green and Cedar Rivers (one in the Green 3022
River and two in the Cedar River). These new outfalls may result in increased scour and decreased 3023
available habitat in the immediate vicinity of the outfalls. The impacts from these outfalls are 3024
considered in the impact numbers for the Project. 3025
3026
Hazardous Materials 3027
Hazardous material spills could have lethal and sublethal effects on fish and micro- and 3028
macroinvertebrate prey at any stream within the action area. During construction, oil, fuel, industrial 3029
fluid, grease, paint, solvents, concrete, asphalt, tar, heavy metals, and other hazardous materials from 3030
construction equipment and stormwater runoff could accidentally enter streams within the action area. 3031
Contaminants can be suspended in the water column or settled on the bottom, and may adhere to 3032
sediment particles. As the particles are deposited, these compounds, or their degradation products, can 3033
bioaccumulate in benthic organisms at much higher concentrations than in the surrounding waters. 3034
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 94
Contaminants can be assimilated into fish tissues by absorption across the gills or through 3035
bioaccumulation as a result of consuming contaminated prey or incidental consumption of sediments 3036
(PFMC 1999). 3037
3038
BMPs will be implemented during Project construction to reduce or eliminate potential sources of 3039
hazardous material contamination. A SPCC Plan for the Project will be prepared by the Contractor, 3040
and submitted to and approved by the Project Engineer prior to commencing construction. Additional 3041
BMPs, conservation measures, and performance standards will be implemented to avoid, minimize, 3042
and control potential discharges of hazardous materials into the environment. 3043
3044
New In-water Structures/Overwater Cover 3045
Overwater cover refers to structures that span over the top of waterbodies and include bridges and fly-3046
over ramps that will be constructed as part of the Project. Shading can have both beneficial and 3047
negative effects with regard to fish habitat. Fish and aquatic species are sensitive to incremental shifts 3048
in temperatures outside of their natural range. Often, stream systems in urban settings, including many 3049
in the Project area, have elevated stream temperatures that are a potential threat to fish life. The 3050
scientific community has largely attributed these increases in water temperature to effects of 3051
impervious surfaces such as pavement, which heat stormwater runoff, and the reduction in shading 3052
provided by riparian trees (GWEB 1997). Shading from the new bridges over water may help reduce 3053
water temperatures and provide a beneficial effect to fish habitat. 3054
3055
Conversely, overwater cover also presents a challenge for aquatic prey species such as juvenile 3056
salmon. The likelihood of predation is higher in these sections of a stream and certain fish species 3057
have demonstrated an aversion to segments with over-water cover. Predator species may concentrate 3058
in these areas, making passage for prey species difficult (Battelle 2006). 3059
3060
The Project will create additional overwater cover on: the Green River, Rolling Hills Creek, an 3061
unnamed tributary to Rolling Hills Creek, and the Cedar River. The Project may remove overwater 3062
cover over Gilliam Creek through the removal of the Tukwila Parkway on-ramp to I-405 north of 61st 3063
Avenue and the existing pedestrian bridge and its supporting pier (the pier is located within the 3064
OHWM of the Cedar River) over the Cedar River, if required for mitigation during future Project 3065
stages. 3066
3067
Permanent In-Water Structures 3068
The built Project will result in permanent structures including pilings, roadways, retaining walls, bank 3069
stabilization measures, culverts, and drainage features located within the existing OHWM of several 3070
rivers and streams in the study area. Placement of permanent structures within the OHWM will reduce 3071
the amount of in-stream habitat available for aquatic dependant organisms and can also reduce the 3072
waterbodies' ability to transport and store water, sediment, nutrients, and other materials; and provide 3073
for groundwater recharge and floodwater storage. 3074
3075
Permanent pilings may be placed within the OHWM of Gilliam Creek, the Green River, Rolling Hills 3076
Creek, the unnamed tributary to Rolling Hills Creek, and Thunder Hills Creek. These pilings are 3077
necessary to construct bridges, retaining walls, and fly-over ramps associated with the Project. 3078
Permanent pilings can affect these waterbodies by causing streambed scour that increases 3079
sedimentation and changes to the streambed's sediment composition. 3080
3081
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 95
Expansion of the I-405 and SR 167 roadway within the study area will result in portions of the 3082
roadway prism or new or extended culverts being placed within the OHWM of Gilliam Creek, Panther 3083
Creek, Rolling Hills Creek, the unnamed tributary to Rolling Hills Creek, and the unnamed tributary to 3084
Thunder Hills Creek. 3085
3086
An approximately 1 mile segment of Panther Creek flows parallel to SR 167 before flowing through a 3087
fish ladder and culvert underneath SR 167 and East Valley Road. The expanded SR 167 roadway and 3088
associated fill prism will be located within Panther Creek for the entirety of the area where Panther 3089
Creek flows parallel to SR 167, resulting in an almost complete loss of the main channel of Panther 3090
Creek in this area. This entire segment of Panther Creek will need to be relocated within the Panther 3091
Creek wetland complex to compensate for lost habitat functions. The relocation of Panther Creek will 3092
occur prior to the construction of SR 167. In addition to the effects on the east side of SR 167, a 3093
portion of Panther Creek on the west side of SR 167 will be filled to accommodate widening of the 3094
SR 167. 3095
3096
Fill will be placed within the OHWM of Rolling Hills Creek, the unnamed tributary to Rolling Hills 3097
Creek, and the unnamed tributary to Thunder Hills Creek to accommodate the expanded right-of-way. 3098
Portions of all of these creeks will also be placed in expanded existing or presently non-existing, new 3099
culverts to accommodate stream flow through the expanded road prism. Retaining walls will be placed 3100
within the OHWM of Rolling Hills Creek and the unnamed tributary to Thunder Hills Creek to 3101
minimize the effects of road widening. 3102
3103
Compensatory mitigation for stream and riparian impacts will be implemented to offset Project 3104
impacts. The proposed mitigation actions have not yet been finalized, but will adhere to the 3105
requirements of the applicable local, state, and federal permits obtained for the Project. 3106
3107
Fish Barrier Removal 3108
WSDOT has identified seven existing culverts that are fish barriers where in-water work will occur. 3109
These fish passage barriers occur on Panther Creek, Rolling Hills Creek, an unnamed tributary to 3110
Rolling Hills Creek, and Thunder Hills Creek. As part of the Project, WSDOT will conduct additional 3111
review on the seven culverts to determine which culverts will be replaced with fish passable structures. 3112
3113
Per the WSDOT Memorandum of Agreement (MOA) with WDFW (WSDOT and WDFW 2002), the 3114
seven existing fish barriers in the study area will be evaluated for replacement with new fish passable 3115
structures such as fish ladders, bridges, and fish-passable culverts. Replacement of fish passage 3116
barriers can provide access to presently inaccessible fish habitat. By opening up inaccessible habitat, 3117
fish species will be provided new spawning, rearing, migrating, and refugia habitat opportunities. As a 3118
result of these new opportunities, fish populations within and outside of the study area will have the 3119
potential to increase in size. 3120
3121
Removal of fish passage barriers can result in changes to a waterbody’s substrate both up- and 3122
downstream of the barrier including changes to substrate composition and gradient. All fish passage 3123
structures will be designed to minimize negative effects that could result from removal of the barrier 3124
such as bed scour and associated loss of pool habitat. 3125
3126
5.1.1.4 Effects Determination 3127
This Project may affect, and is likely to adversely affect, the Puget Sound ESU of Chinook salmon. 3128
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 96
3129
This Project may affect Chinook for the following reasons: 3130
1. Suitable migration, spawning, and rearing habitat is present within the action area 3131
2. New permanent structures will be placed in waterbodies known to contain Chinook salmon; 3132
suitable migration and rearing habitat will be destroyed as a result of the Project 3133
3. Riparian vegetation will be permanently removed from waterbodies known or assumed to 3134
contain Chinook salmon 3135
4. Water quality will be temporarily degraded as a result of in-water work 3136
5. Construction that could disturb the in-water environment, including pile driving and 3137
dewatering, will occur in waterbodies known to contain Chinook salmon 3138
3139
This Project is likely to adversely affect Chinook because: 3140
1. Chinook salmon may be present in the vicinity of the Project during the time of year when 3141
construction activities will occur, though exposure will be limited by adhering to applicable in-3142
water work windows 3143
2. New temporary and permanent piling will be placed in the Green River, which is known to 3144
contain Chinook salmon and suitable migration and rearing habitat 3145
3. Rearing juvenile Chinook salmon are known to be present in the area of the Green River that 3146
will be affected by the Project. 3147
3148
5.1.1.5 Critical Habitat 3149
Critical habitat has been designated for the Puget Sound ESU of Chinook salmon. Within the 3150
Duwamish Subbasin, Unit 11 (HUC 17110013), lower Green River watershed, the Green River and 3151
Springbrook Creek are identified as critical habitat. Within the Lake Washington Subbasin, Unit 10 3152
(HUC 17110012), the Cedar River watershed, the Cedar River is designated as critical habitat. 3153
3154
PCEs 3155
The relevant Primary Constituent Elements (PCEs)s related to the Project area are: 3156
1. Freshwater rearing sites with water quantity and floodplain connectivity to form and maintain 3157
physical habitat conditions and support juvenile growth and mobility; water quality and forage 3158
supporting juvenile development; and natural cover such as shade, submerged and overhanging 3159
large wood, log jams and beaver dams, aquatic vegetation, large rocks and boulders, side 3160
channels, and undercut banks 3161
2. Freshwater migration corridors free of obstruction with water quantity and quality conditions 3162
and natural cover such as submerged and overhanging large wood, aquatic vegetation, large 3163
rocks and boulders, side channels, and undercut banks supporting juvenile and adult mobility 3164
and survival 3165
3166
The freshwater rearing sites and migration corridors PCEs will be impacted by the Project through 3167
temporary disturbances in water quality from construction activities associated with the Project, and 3168
permanently impacted through removal of habitat, placement of permanent in-water structures, and 3169
potentially through habitat improvements resulting from mitigation for the Project. 3170
3171
In the action area, the Green and Cedar Rivers and Springbrook Creek are largely disconnected from 3172
their floodplains due to historic channelization and diking activities. All three waterbodies are also 3173
listed on Ecology’s 303(d) list: the Green River for temperature, fecal coliform, and DO; the Cedar 3174
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 97
River for exceedances of fecal coliform and temperature; and Springbrook Creek for exceedances of 3175
fecal coliform and DO. Additionally, all three waterbodies in the action area are largely devoid of 3176
native riparian vegetation and in-water cover due to past human activities. Therefore, the specific 3177
elements that define the freshwater rearing site and migration corridor PCEs are largely non-existent 3178
within the action area. 3179
3180
The Green and Cedar Rivers will both incur impacts below the OHWM as a result of the Project. New 3181
structures will be placed below the OHWM of the Green River to accommodate the replacement or 3182
reconstruction of five bridges (the new Tukwila Parkway bridge will be free spanned). The addition of 3183
these structures will decrease the total amount of available Chinook salmon critical habitat in the 3184
Green River. One permanent pier that presently supports the existing pedestrian bridge over the Cedar 3185
River may be removed as mitigation for Project impacts. If this pier were removed, it would increase 3186
the total amount of available Chinook salmon critical habitat in the Cedar River. Additionally, 3187
compensatory mitigation for stream and riparian impacts will be implemented to offset Project 3188
impacts. All mitigation activities for impacts to the Green and Cedar Rivers will be performed directly 3189
in either the Green or Cedar Rivers (based on where the impact will occur) and will be designed to 3190
mitigate for the functions lost as a result of the Project impacts. All mitigation for impacts to the 3191
Green and Cedar Rivers will be performed in accordance with the most recent version of the local 3192
critical areas ordinances at the time of construction and will compensate for lost functions. The 3193
proposed mitigation actions have not yet been finalized but will adhere to the requirements of the 3194
applicable local, state, and federal permits obtained for the Project. 3195
3196
5.1.1.6 Chinook Salmon Critical Habitat Effects Determination 3197
This Project may affect Chinook salmon critical habitat for the following reasons: 3198
1. Critical habitat is in the Project footprint and will be impacted by Project activities 3199
3200
This Project is likely to adversely affect Chinook salmon critical habitat because of: 3201
1. Temporary increases in turbidity in the Green and Cedar Rivers from construction 3202
2. Temporary decreases in the overall amount of available critical habitat will occur until 3203
mitigation is established 3204
3. Increased obstructions in the Green River 3205
4. Construction of new overwater structures over the Green and Cedar Rivers 3206
5. Removal of existing riparian vegetation along the Green and Cedar Rivers 3207
3208
5.1.2 Puget Sound Steelhead 3209
5.1.2.1 Status 3210
Steelhead trout are listed as threatened. 3211
3212
Source of information pertaining to documented occurrence: 3213
1. WDFW Priority Habitat Species Data for WRIAs 8 and 9 3214
2. WRIA 8 and 9 Limiting Factors Analysis 3215
3. WDFW Salmonscape - Accessed 5/1/07 3216
3217
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 98
5.1.2.2 Biology and Distribution in the Action Area 3218
Winter steelhead are known to use the Green River for spawning, rearing, migration, and foraging. 3219
Spawning occurs in April and May. Winter steelhead have been documented in the Cedar River, 3220
though spawning has not been observed. Steelhead may use portions of Springbrook, Panther, and 3221
Gilliam Creeks for rearing and foraging. Resident steelhead may be present in the Green and Cedar 3222
River systems. Because steelhead are so variable in their length of freshwater and marine residence, it 3223
is difficult to predict which life stages may be present at different times of year. 3224
3225
Various life stages of steelhead could be found in the waterbodies located in the action area at any time 3226
of year, and steelhead are very likely to be in the area in late spring. Steelhead exhibit a wide variety 3227
of residence times in freshwater and saltwater, and it is difficult to predict whether or not they will 3228
occur at other times of the year. Specific life history stages of steelhead that could occur in the 3229
waterbodies in the action area are further detailed in the following paragraphs. 3230
3231
Green River 3232
Summer and winter steelhead are known to use the Green River. Resident forms may also occur. 3233
Steelhead presence is documented in the Green River, but no known spawning or rearing is 3234
documented in the action area. Because migration time is highly variable and steelhead can spawn 3235
more than once, juveniles and adults may occur at any time of year. 3236
3237
Cedar River 3238
Winter-run steelhead are known to rear in the Cedar River within the action area, but no known 3239
spawning is documented. Summer-run and resident forms are not documented, but may occur. 3240
3241
Springbrook Creek 3242
Steelhead spawning does not occur in Springbrook Creek. While no steelhead use is documented, it is 3243
possible that resident and/or anadromous steelhead use Springbrook Creek as a rearing and foraging 3244
area. 3245
3246
Gilliam Creek 3247
Steelhead use is not documented in Gilliam Creek. However, due to its association with the Green 3248
River, life history stages of steelhead that could occur in Gilliam Creek in the action area are likely 3249
limited to fry that would use Gilliam Creek as an off-channel rearing or foraging area. 3250
3251
Panther Creek 3252
Steelhead use is not documented in Panther Creek; however, it is possible that resident and/or 3253
anadromous steelhead use Panther Creek as a rearing and foraging area. Steelhead are not presumed to 3254
be present in the west fork of Panther Creek. 3255
3256
5.1.2.3 Direct and Indirect Effects 3257
The effects on steelhead are the same as for Chinook salmon. Refer to Section 5.1.1.3 for details. 3258
3259
5.1.2.4 Effects Determination 3260
The Project may affect Puget Sound steelhead for the following reasons: 3261
1. Suitable migration, spawning, and rearing habitat is present within the action area 3262
2. Suitable steelhead migration and rearing habitat will be destroyed as a result of the Project 3263
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 99
3. Riparian vegetation will be permanently removed from waterbodies known or assumed to 3264
contain steelhead 3265
4. Water quality will be temporarily degraded as a result of in-water work 3266
5. Construction that could disturb the in-water environment, including pile driving and 3267
dewatering, will occur in waterbodies known to contain steelhead 3268
6. The Panther Creek main channel will be relocated as a result of the Project 3269
3270
This Project is likely to adversely affect steelhead because: 3271
1. Steelhead may be present in the vicinity of the Project during the time of year when 3272
construction activities will occur, though exposure will be limited by adhering to applicable in-3273
water work windows 3274
2. A new permanent SR 167 auxiliary lane will encroach into the OHWM of Panther Creek, 3275
which is known to contain suitable steelhead migration and rearing habitat 3276
3277
5.1.2.5 Critical Habitat 3278
Critical habitat has not been designated or proposed for Puget Sound steelhead. 3279
3280
5.2 USFWS-Listed Species 3281
5.2.1 Bull Trout 3282
5.2.1.1 Status 3283
Bull trout are listed as threatened. 3284
3285
5.2.1.2 Biology and Distribution in the Action Area 3286
Bull trout are infrequently observed in the action area. Historically, they used the Green/Duwamish 3287
and Cedar River systems in greater numbers (Kerwin and Nelson 2000). 3288
3289
Bull trout use has been documented in Lake Washington, which is located approximately 2.5 miles 3290
from the action area. Bull trout have been documented to use the Green River up to RM 41, and are 3291
consistently reported in the lower Duwamish River (USFWS 2004). Bull trout are also known to use 3292
the lower Cedar River for foraging and as a migration corridor. 3293
3294
Bull trout use of any of the remaining waterbodies in the action area has not been documented. 3295
3296
Historically, bull trout were reported to use the Duwamish River and lower Green River in “vast” 3297
numbers (Suckley and Cooper 1860). However, bull trout are observed infrequently in this system 3298
today. In recent times, bull trout have been reported on the lower Green River as far upstream as the 3299
mouth of Newaukum Creek at approximately RM 41, and are consistently reported in the lower 3300
Duwamish River (USFWS 2004). In addition, the Lake Washington system (including the Cedar 3301
River), the lower Green River, and the marine areas of Puget Sound have been identified as containing 3302
important foraging, migration, and overwintering habitat necessary for bull trout recovery (USFWS 3303
2004). 3304
3305
It is not known whether the bull trout observed in the lower Green River Basin are foraging individuals 3306
from other core areas, or if natural reproduction may still persist somewhere within the basin. Based 3307
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 100
on observed behavior from other systems within the management unit and based on the size of 3308
individuals typically reported, there is a strong likelihood that bull trout in the lower Green River are 3309
anadromous migrants from other core areas. Reports of historic bull trout use of the lower Green River 3310
tributaries are rare, and there have been no recent observations (USFWS 2004). 3311
3312
Bull trout use of the other waterbodies in the action area is unlikely due to the highly urbanized nature 3313
of these waterbodies. Bull trout have more specific habitat requirements than most other salmonids. 3314
Habitat components greatly influence bull trout distribution, abundance, and rearing and reproductive 3315
abilities. High water temperatures and large amounts of fine sediment resulting in high embeddedness, 3316
such as is found in the streams of the action area, typically limit bull trout use of a waterbody. 3317
3318
Adult bull trout are the only life history stage likely to occur in the action area. The Lake Washington 3319
system has been identified as containing important foraging, migration, and overwintering habitat 3320
necessary for bull trout recovery, but no known bull trout spawning occurs in Lake Washington and 3321
the bull trout found there are likely from the Snohomish-Skykomish and Stillaguamish River systems 3322
(69 Fed Reg 35795). 3323
3324
Bull trout use the Cedar and Green Rivers for up and downstream migration and for foraging (WSDOT 3325
2005b). Bull trout could be present in the Green or Cedar Rivers at any time of year, though high 3326
summer temperatures in these rivers may limit use during that time of year. It is not presumed that bull 3327
trout will be present during any time of year in the remaining waterbodies in the action area. 3328
3329
5.2.1.3 Direct and Indirect Effects 3330
The effects on bull trout are the same as for Chinook salmon. Refer to Section 5.1.1.3 for details. 3331
3332
5.2.1.4 Effects Determination 3333
This Project may affect, but is likely to adversely affect bull trout. 3334
3335
This Project may affect bull trout for the following reasons: 3336
1. Suitable migration habitat is present within the action area 3337
2. New permanent structures will be placed in waterbodies known to contain bull trout; suitable 3338
migration and rearing habitat will be destroyed as a result of the Project 3339
3. Riparian vegetation will be permanently removed from waterbodies known or assumed to 3340
contain bull trout 3341
4. Water quality will be temporarily degraded as a result of in-water work 3342
5. Construction that could disturb the in-water environment, including pile driving and 3343
dewatering, will occur in waterbodies known to contain bull trout 3344
6. Prey species (salmon) may be adversely affected as a result of the Project 3345
3346
This Project is likely to adversely affect bull trout because: 3347
1. Bull trout may be present in the vicinity of the Project during the time of year when 3348
construction activities will occur, though exposure will be limited by adhering to applicable in-3349
water work windows. 3350
2. New temporary and permanent piling will be placed in the Green River, which is known to 3351
contain bull trout and suitable migration and rearing habitat 3352
3353
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 101
5.2.1.5 Critical Habitat 3354
Designated bull trout critical habitat in the action area consists of the Green River, which is primarily 3355
used for migration. Critical habitat designates areas that contain the physical and biological habitat 3356
features (PCEs) essential for the conservation and recovery of bull trout. For an area to be included as 3357
critical habitat, it has to provide one or more of the following functions for bull trout: 3358
1. Spawning, rearing, foraging, or over-wintering habitat to support essential existing local 3359
populations 3360
2. Movement corridors necessary for maintaining essential migratory life history forms 3361
3. Suitable habitat that is considered essential for recovering existing local populations that have 3362
declined or that need to be established to achieve recovery 3363
3364
Areas providing one or more of these functions and at least one of the following nine PCEs are 3365
designated as critical habitat: 3366
1. Water temperatures ranging from 36 to 59° F (2 to 15° C), with adequate thermal refugia 3367
available for temperatures at the upper end of this range. Specific temperatures within this 3368
range will vary depending on bull trout life history stage and form, geography, elevation, 3369
diurnal and seasonal variation, shade (such as that provided by riparian habitat), and local 3370
groundwater influence. 3371
2. Complex stream channels with features such as woody debris, side channels, pools, and 3372
undercut banks to provide a variety of depths, velocities, and in-stream structures. 3373
3. Substrates of sufficient amount, size, and composition to ensure success of egg and embryo 3374
overwinter survival, fry emergence, and juvenile survival. A minimal amount of fine substrate 3375
less than 0.25 inches (0.63 centimeters) in diameter and minimal substrate embeddedness are 3376
characteristic of these conditions. 3377
4. A natural hydrograph, including peak, high, low, and base flows within historic ranges or, if 3378
regulated, a hydrograph that demonstrates the ability to support bull trout populations by 3379
minimizing daily and day-to-day fluctuations and minimizing departures from the natural cycle 3380
of flow levels corresponding with seasonal variation. 3381
5. Springs, seeps, groundwater sources, and subsurface water connectivity to contribute to water 3382
quality and quantity. 3383
6. Migratory corridors with minimal physical, biological, or water quality impediments between 3384
spawning, rearing, overwintering, and foraging habitats, including intermittent or seasonal 3385
barriers induced by high water temperatures or low flows. 3386
7. An abundant food base including terrestrial organisms of riparian origin, aquatic 3387
macroinvertebrates, and forage fish. 3388
8. Few or no non-native predatory, interbreeding, or competitive species present. 3389
9. Permanent water of sufficient quantity and quality such that normal reproduction, growth, and 3390
survival are not inhibited. 3391
3392
Most of these PCEs do not exist in the action area. However, migratory corridors and permanent water 3393
of sufficient size are present in the action area, though limited in their abilities to meet the PCE 3394
standards above. 3395
3396
The Green River does not support a local bull trout population, but does provide a movement corridor 3397
necessary for maintaining essential migratory life history forms. In the action area, the Green River is 3398
largely disconnected from its floodplains due to historic channelization and diking activities. The 3399
Green River is also listed on Ecology’s 303(d) list for temperature, fecal coliform, and DO. 3400
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 102
Additionally, the Green River in the action area is largely devoid of native riparian vegetation and in-3401
water cover due to past human activities. Therefore, the specific elements that define the migratory 3402
corridors and permanent water of sufficient size PCEs are largely non-existent within the action area. 3403
3404
The Green River will incur impacts below the OHWM as a result of the Project. New structures will 3405
be placed below the OHWM of the Green River to accommodate the replacement or reconstruction of 3406
five bridges (the new Tukwila Parkway bridge will be free spanned). The addition of these structures 3407
will decrease the total amount of available bull trout critical habitat in the Green River. Compensatory 3408
mitigation for stream and riparian impacts will be implemented to offset Project impacts. All 3409
mitigation activities for impacts to the Green River will be performed directly in the Green River and 3410
will be designed to mitigate for the functions lost as a result of the Project impacts. All mitigation for 3411
impacts to the Green River will be performed in accordance with the most recent version of the local 3412
critical areas ordinances at the time of construction and will compensate for lost functions. The 3413
proposed mitigation actions have not yet been finalized but will adhere to the requirements of the 3414
applicable local, state, and federal permits obtained for the Project. 3415
3416
5.2.1.6 Bull Trout Critical Habitat Effects Determination 3417
This Project may affect bull trout critical habitat for the following reasons: 3418
1. Critical habitat in Project footprint will be impacted by Project activities 3419
3420
This Project is likely to adversely affect bull trout critical habitat because: 3421
1. The Project will increase obstructions in foraging habitats 3422
2. Temporary decreases in the overall amount of available critical habitat will occur until 3423
mitigation is established 3424
3425
5.2.2 Bald Eagle 3426
5.2.2.1 Status 3427
The bald eagle is listed as threatened. 3428
3429
5.2.2.2 Biology and Distribution 3430
The nearest eagle nest is approximately 2.1 miles from the Project area and 1.6 miles from the 1 mile 3431
action area boundary. The eagle’s territory extends no closer than 1.8 miles to the Project area. 3432
3433
Eagle occurrence in the region is well documented by WDFW. Eagles enter an area for perching, 3434
nesting, foraging, and migratory purposes. There are few tall trees close to the highway and few 3435
foraging opportunities in the urban development corridor along the highway. More suitable areas exist 3436
along the shore of Lake Washington and in the less-developed areas southeast of the Project area, 3437
toward Mount Rainier. 3438
3439
Eagles are not documented to occur within the Project area. Eagles do occur in the surrounding area 3440
along the Lake Washington shoreline and the Cascade Foothills. The Project area is within the 3441
Western Flyway, a major bird migration corridor. Eagles from outside the area may be present in 3442
winter, but prefer high perch sites with a water view. These eagles are likely to avoid the urbanized 3443
highway corridor in favor of the surrounding areas, which contain forested shoreline habitat with less 3444
urban encroachment. 3445
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 103
3446
The Project action area is highly urbanized. While some forested areas exist, less developed areas 3447
exist outside of action area that are far more suitable for use by eagles. 3448
3449
There is no known bald eagle nesting, over-wintering, or roosting habitat in the action area. The 3450
nearest eagle territory does not extend to the Project action area boundary. Migrating eagles could fly 3451
over the site, but are unlikely to forage or perch there due to the lack of suitable perching trees and the 3452
limited prey availability. 3453
3454
Eagles are unlikely to use the Project action area. In the less-developed areas surrounding the action 3455
area, nesting occurs from January 1 to August 15 (USFWS 1986). Wintering occurs from October 31 3456
to March 31. Eagles from outside the region may forage in the action area during this time. Perches 3457
are most often associated with food sources near water that have visual access to adjacent habitats 3458
(Stalmaster and Newman 1979). Perching is not likely to occur near the highway. Foraging may 3459
occur year-round, and is most likely near rivers and streams. 3460
3461
5.2.2.3 Direct and Indirect Effects 3462
The nearest eagle nest is approximately 2.1 miles from the Project area and 1.6 miles from the 1 mile 3463
action area boundary. The eagle’s territory extends no closer than 1.8 miles to the Project area, with 3464
no line of sight to construction activities. The nest is well beyond the 2,625-foot setback 3465
recommended by USFWS to avoid disturbance to nesting eagles, thus the Project is not subject to 3466
timing restrictions for the protection of nesting eagles. There is no known bald eagle nesting, over-3467
wintering, or roosting habitat in the action area. The nearest eagle territory does not extend to the 3468
Project action area boundary. Migrating eagles could fly over the site, but are unlikely to forage or 3469
perch there due to the lack of suitable perching trees and the limited prey availability. 3470
3471
5.2.2.4 Bald Eagle Effects Determination 3472
Due the lack of use of the area, no direct or indirect effects to bald eagles are anticipated as a result of 3473
the Project. 3474
3475
5.3 Indirect Effects of Induced Growth 3476
Indirect effects of transportation projects include changes in land use, such as the development of 3477
undeveloped areas when those changes are induced by the action or can reasonably be expected to 3478
result from the action. To determine potential indirect effects of induced growth, WSDOT coordinated 3479
with NMFS, USFWS, FHWA, and the Office of Community Development to develop a step-by-step 3480
approach to assessing indirect effects by posing a series of questions about the proposed Project. This 3481
step-by-step process to assess effects from the Project is outlined below. 3482
3483
Does the project create a new facility or increase the capacity of the existing system? 3484
The Project does create new facilities and increases the capacity of the existing I-405 system. 3485
3486
Is there new development contingent on the Project? 3487
The Land Use Analysis for the I-405 Projects reviewed zoning ordinances and did not identify 3488
any instances of developments being tied to the I-405 Projects by permit condition or building 3489
moratoria (WSDOT 2004). The analysis also reviewed the local Comprehensive Plans for 3490
Land Use, Transportation, and Capital Facilities goals and policies, and found that there are no 3491
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 104
developments tied to the I-405 Projects by permit conditions or moratoria (WSDOT 2004). 3492
The Renton Comprehensive Plan indicates that the City’s policies will improve transportation 3493
facilities to meet existing and future (proposed) development transportation needs, illustrating 3494
that local transportation projects are in response to need, as opposed to a catalyst to future 3495
development (WSDOT 2004). In addition, The Renton Comprehensive Plan includes policies 3496
that require transportation improvements, strategies, and actions to be in place at the time new 3497
development occurs or be financially committed and scheduled for completion within 6 years. 3498
3499
The Project will not result in planned development being approved that may otherwise have 3500
been denied. The Cities of Renton and Tukwila do not currently have permit conditions or any 3501
moratorium on development activities based on I-405 traffic levels. The I-405 Team has found 3502
no evidence that the cities of Renton and Tukwila will change land use designations for 3503
properties based on the Project. This is based on a review of the Land Use, Transportation, and 3504
Capital Facilities portions of the cities of Renton’s and Tukwila’s Comprehensive Plans. 3505
3506
The Project is not anticipated to result in focused development at any location. Development 3507
within the Renton and Tukwila areas is based on the Cities’ Comprehensive Plans, which in 3508
turn are based on Puget Sound Regional Council planning and the Growth Management Act. 3509
As such, state, regional and local land use planning already identifies the expected land use and 3510
the I-405 Projects, including the Project, are built to accommodate this planned development. 3511
3512
As no new development is contingent on the Project, there are no anticipated indirect effects to listed 3513
species from induced growth as a result of the Project. 3514
3515
5.4 Effects of Interrelated and Interdependent Actions 3516
The only interrelated action associated with the Project is the Springbrook Wetland and Habitat 3517
Mitigation Bank (Springbrook Bank). 3518
3519
A portion of the Springbrook Bank is anticipated to provide compensation for unavoidable impacts to 3520
wetlands and other aquatic resources resulting from the Project. It was developed by WSDOT and the 3521
City of Renton and will provide compensatory mitigation for unavoidable impacts caused by the 3522
Project, as it is in the service area of the Springbrook Bank. The Springbrook Bank has been permitted 3523
and consulted on separately from the Project. 3524
3525
Construction of the Springbrook Bank will provide new and enhanced wetland habitat in the vicinity of 3526
the action area. There may be temporary impacts associated with construction of the Springbrook 3527
Bank; however, it is anticipated that construction of the bank will result in an overall improvement to 3528
habitat conditions in the vicinity of the Project. 3529
3530
5.5 Cumulative Effects 3531
The cities of Renton and Tukwila have land use regulations, including critical areas and shoreline 3532
ordinances, that protect the various habitat types found in the action area. A discussion of these 3533
regulations related to Project impacts can be found in Section 2.1.7.2. In addition, state regulations are 3534
in place that protect water quality and wildlife habitat in the action area. Enforcement of these 3535
regulations is anticipated to minimize impacts to listed species as a result of any new development. 3536
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 105
Based on the existing protections provided by local and state regulations related to new development, 3537
there are no anticipated cumulative effects to federally listed species as a result of these potential 3538
actions. 3539
3540
3541
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 107
6. Summary of Project Components, Impacts, and Minimization 3542
Measures 3543
The Project has been designed to minimize impacts to the environment. Specifically, the following 3544
components were incorporated into the design: 3545
• Retaining walls were used to limit in-water impacts to Gilliam Creek, Rolling Hills Creek, an 3546
unnamed tributary to Rolling Hills Creek, Thunder Hills Creek, an unnamed tributary to 3547
Thunder Hills Creek, Panther Creek, and the Panther Creek wetlands (Wetland 24.7R) 3548
• Roadway alignments were shifted to reduce impacts to wetlands throughout the Project area 3549
• A new bridge will be constructed over the Nelson Channel to avoid impacts to this wetland 3550
• The interchange configuration constructs ramps as bridges over local/ mainline roadways to 3551
minimize the Project footprint 3552
• Bridges over the Cedar River will be free spanned. Free spanning the bridges over the Green 3553
River is not practicable, as detailed in Section 2.1.5.3. 3554
• The new Tukwila Parkway bridge over the Green River will be free spanned and the associated 3555
approaches will include retaining walls to minimize riparian buffer impacts. 3556
3557
In addition, WSDOT will implement the BMPs, minimization measures, and performance standards 3558
listed in the following sections. 3559
3560
6.1 Summary of BMPs/Minimization Measures 3561
• Work below the OHWM will be conducted during the WDFW in-water work window, June 15 3562
through September 30 in each year when construction will occur. Fish exclusion will be 3563
conducted in accordance with WSDOT’s fish removal and exclusion protocols found in 3564
Appendix D of this BA. 3565
• WSDOT will prepare and implement a revegetation plan and minimize the amount of 3566
vegetation clearing to retain as many trees as practicable to minimize impacts to upland 3567
vegetation. 3568
• All equipment to be used for construction activities shall be cleaned and inspected prior to 3569
arriving at the Project site, to ensure no potentially hazardous materials are exposed, no leaks 3570
are present and the equipment is functioning properly. Erosion control devices (i.e., silt fence) 3571
will be installed as needed to protect surface waters and other critical areas. Actual location 3572
will be specified in the field, based upon site conditions. 3573
• Site work shall be limited to daylight hours to the extent practicable and local, state, and federal 3574
permit restrictions will be followed. 3575
• The Contractor will designate at least one employee as the ESC lead. The ESC lead will be 3576
responsible for the installation and monitoring of erosion control measures and maintaining 3577
spill containment and control equipment. The ESC lead will also be responsible for ensuring 3578
compliance with all local, state, and federal erosion and sediment control requirements. 3579
• Material that may be temporarily stored for use in Project activities shall be covered with 3580
plastic or other impervious material to prevent sediments from being washed from the storage 3581
area to surface waters. 3582
• All temporary and permanent erosion and sedimentation control measures will be inspected on 3583
a regular basis, maintained and repaired to assure continued performance of their intended 3584
function. 3585
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 108
• Silt fences will be inspected immediately after each rainfall, and at least daily during prolonged 3586
rainfall. Sediment will be removed as it collects behind the silt fences and prior to their final 3587
removal. 3588
• Exposed soils will be seeded and covered with straw mulch after construction is complete. Any 3589
temporary construction impact areas will be revegetated with native plants. 3590
• All bare soil areas will be hydro-seeded and all temporarily disturbed areas revegetated with 3591
native vegetation following final grading activities. 3592
• All silt fencing and staking will be removed upon Project completion. 3593
• Construction equipment used for Project activities will be operated from existing roads or the 3594
streambank (above the OHWM). Construction equipment shall not enter the active stream 3595
channel, below the OHWM. 3596
• Clearing limits will be delineated with orange barrier fencing prior to commencing clearing 3597
activities wherever clearing is proposed in or adjacent to a stream/wetland or its buffer. 3598
• A TESC Plan will be developed and implemented for all projects requiring clearing, vegetation 3599
removal, grading, ditching, filling, embankment compaction, or excavation. The BMPs in the 3600
plans will be used to control sediments from all vegetation removal or ground disturbing 3601
activities. 3602
• The Contractor shall prepare a SPCC Plan prior to beginning construction. The SPCC Plan 3603
shall identify the appropriate spill containment materials, which will be available at the Project 3604
site at all times. 3605
• All in-water work will conform the requirements of the HPA issued for the Project. 3606
• Only clean rock will be placed below the OHWM; clean rock shall consist of various types and 3607
sizes, depending upon application, that contains no fines, soils, or other wastes or contaminants. 3608
• Where practicable, excavation activities shall be accomplished in the dry. All surface water 3609
flowing towards the excavation shall be diverted through utilization of cofferdams and/or 3610
berms. Cofferdams and berms must be constructed of sandbags, clean rock, steel sheeting, or 3611
other non-erodible material. 3612
• Coffer dams will not be installed with an impact driver. Coffer dams will be installed with a 3613
vibratory driver or another method as approved by WSDOT. 3614
• Bank shaping shall be limited to the minimum necessary. 3615
• No paving, chip sealing, or stripe painting will occur during periods of rain or wet weather. 3616
• If equipment use within the wetted perimeter is permitted, the following provisions shall apply: 3617
1. Equipment shall be thoroughly cleaned of mud, petroleum products, or other deleterious 3618
material. 3619
2. Turning and spinning within the streambed shall be avoided. 3620
3. The streambed shall be returned to pre-Project condition at Project completion. 3621
4. The amount and duration of in-stream work with machinery will be limited to the 3622
minimum amount necessary to complete the work. 3623
• There will be no visible sheen from petroleum products in the receiving water as a result of 3624
Project activities. 3625
• WSDOT policy and construction administration practice is to have a WSDOT Environmental 3626
Compliance Assurance Inspector on site during construction. The role of the inspector will 3627
ensure contract and permit requirements. 3628
• WSDOT environmental staff will provide guidance and instructions to the Environmental 3629
Compliance Assurance Inspector to ensure the inspector is aware of permit requirements. 3630
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 109
• No excavated material will be placed in the existing stream channels. Excavated material will 3631
be removed to a location that will prevent its reentry into waters of the State. 3632
• All temporary material storage piles will be protected by appropriate BMPs to prevent 3633
sediments from leaving the piles and entering surface waters. 3634
• If necessary, divert stream flow around culvert replacement sites through a temporary culvert, 3635
or a trench lined with plastic, rocks, or other suitable material to prevent erosion. 3636
• Accumulations of bird feces, road grit, sand, and loose paint chips shall be removed to the 3637
greatest extent practicable prior to disassembling the existing bridge. 3638
• Drip tarps shall be suspended below paint platforms to prevent spilled paint, buckets, brushes, 3639
etc. from entering State waters. 3640
• Pressure washing of bridge structures shall be done using appropriate screened tarping to 3641
control and contain paint particles generated by the activity. Concentrated accumulations of 3642
bird feces and nests shall not be allowed to drop into the water. This material shall be scraped 3643
from the bridge structure and collected and disposed of at an appropriate upland location. 3644
• During abrasive blasting of a steel bridge prior to painting, a containment system appropriate 3645
for the type and location of the bridge shall be in place and maintained to prevent spent blast 3646
media from reaching state waters. Spent blast media shall be collected, sampled, designated for 3647
its hazardous material content, and disposed of as appropriate for its waste designation. 3648
• Debris accumulations on the bridge, road surface, and within the bridge drains shall be 3649
collected or swept up and properly disposed of prior to fresh water flushing. Flushing will 3650
involve the use of clean water only, to prevent detergents or other cleaning agents from 3651
entering waters of the State. 3652
• The Contractor shall protect all inlets and catchments from fresh concrete, tackifier, paving, or 3653
paint stripping. 3654
• Installation of riprap and other bank stabilizing materials will occur from the banks or outside 3655
the wetted perimeter as much as possible. 3656
• Living plant material and LWD will be incorporated in the bank protection designs where 3657
appropriate. 3658
• Excess or waste materials will not be disposed of or abandoned waterward of the OHWM or 3659
allowed to enter waters of the State. 3660
• Any floating debris generated during construction will be retrieved. Debris will be disposed of 3661
upland. 3662
• Plastic piling will not be allowed by WSDOT. Untreated wood piling will only be allowed for 3663
temporary construction. No creosote-treated piling will be used. 3664
• Uncured concrete will not come in contact with surface water. 3665
• A concrete truck chute cleanout area or other equally effective BMP shall be established to 3666
properly contain wet concrete. 3667
• Before, during, and immediately after isolation and dewatering of the in-water work area, fish 3668
from the isolated area will be captured and released using trapping, seining, electrofishing, or 3669
other methods as to minimize risk of injury to fish, in accordance with the WSDOT Protocols 3670
for such activities (Appendix D). 3671
• Revegetation of construction easements and other areas will occur after the Project is 3672
completed. All disturbed riparian vegetation will be replanted. Trees will be planted when 3673
consistent with highway safety standards. Riparian vegetation will be replanted with species 3674
native to the action area. 3675
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 110
• All work will be performed according to the requirements and conditions of the HPA issued by 3676
WDFW and appropriate concurrence recommendations identified by the federal agencies 3677
during ESA consultation. All in-water work will occur during the approved in-water work 3678
window, as stipulated by the HPA and ESA consultation. 3679
• At the end of each workday, the work area within the OHWM shall contain no pits, potholes, or 3680
depressions to avoid stranding of fish. 3681
• The Project will follow the ISPG or the HEC 23 (FHWA) recommendations as much as 3682
practicable. 3683
• All replacement culverts will be designed and installed in accordance with the WDFW Culvert 3684
Manual (Bates et al. 1999) where fish passage is required. 3685
• Temporary storage of excavated materials will not occur within the 100-year floodplain 3686
between October 1 and May 1. Material used within 12 hours of deposition will not be 3687
considered temporary. 3688
• Seasonal restrictions (i.e., work windows) will be applied to the Project to avoid or minimize 3689
potential impacts to listed or proposed species based on the HPA issued by the WDFW and 3690
consultation with the USFWS and NMFS. The appropriate in-water work windows for this 3691
Project for the Green River, Gilliam Creek, Panther Creek, and the Cedar River are from June 3692
15 to September 30 each year for the protection of salmonids including Chinook salmon, bull 3693
trout, and steelhead trout. 3694
• All exposed soils will be stabilized during the first available period, and shall not be untreated 3695
for more than 7 days without receiving the erosion control specified in the TESC Plan. For 3696
western Washington, no soils shall remain unstabilized for more than 2 days from October 1 to 3697
April 30, and for more than 7 days from May 1 to September 30. 3698
• The Contractor shall not place temporary material storage piles, including rebar, precast 3699
concrete pipe, steel pipe, and other hard items, in the 100-year floodplain between October 1 3700
and May 1. Material used within 12 hours of deposition will not be considered a temporary 3701
material storage pile. 3702
• Existing piling will be either removed completely or cut a minimum of 2 feet below the 3703
substrate elevation. 3704
• All creosote-treated material, pile stubs, and associated sediments will be disposed of by the 3705
Contractor in a landfill that meets the liner and leachate standards of the Minimum Functional 3706
Standards, Chapter 173-304 WAC. The Contractor will provide receipts of disposal to the 3707
Project Engineer to ensure proper disposal. 3708
• Project staging and material storage areas shall be located a minimum of 150 feet from surface 3709
waters or in currently developed areas such as parking lots or managed fields. 3710
3711
6.2 Summary of Performance Standards 3712
• Pre- versus post-annual pollutant loading shall be analyzed using the WSDOT calculation 3713
spreadsheet to ensure that the water quality facilities results match permit requirements. 3714
• A 3-year monitoring plan of revegetated areas will be implemented to ensure 100 percent 3715
survival of vegetation by stem count at the end of 1 year and 80 percent survival by stem count 3716
at the end of the 3-year monitoring period. 3717
• WSDOT will mitigate for impacts to wetlands, streams, and rivers in accordance with local, 3718
state, and federal permit requirements. Mitigation will be designed to offset wetland, stream, 3719
and river functions lost as a result of Project impacts. 3720
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 111
• All construction activities will comply with water quality standards set forth in the 3721
Implementing Agreement (WSDOT and Ecology 1998) and the State of Washington Surface 3722
Water Quality Standards (WAC 173-201A). The current WSDOT/Ecology Water Quality 3723
Implementing Agreement allows for a mixing zone not to exceed a specified distance 3724
downstream of the Project corridor based on the characteristics of the waterbody. 3725
• Final design may result in changes to the proposed stormwater treatment system, but the 3726
Project will not increase pollutant concentrations discharged to receiving waterbodies. 3727
Additionally, the construction of any new stormwater facilities will be timed such that the 3728
Project meets or reduces the loading and concentration levels detailed in this BA for each stage 3729
of the Project. 3730
• Work below the OHWM will be conducted during the WDFW in-water work windows and any 3731
associated fish exclusion will be conducted in accordance with WSDOT’s fish removal and 3732
exclusion protocols found in Appendix D of this BA. Stream and river bypasses or dewatering 3733
will occur during the driest time of the year when fish are least likely to be present and will be 3734
performed in accordance with applicable permit conditions and WSDOT Standard 3735
Specifications. 3736
3737
6.3 Impacts Summary 3738
Permanent impacts from the Project include removal of 34 acres of vegetation (including 6.74 acres of 3739
riparian vegetation), filling of 7.50 acres of wetlands, and permanent impacts to 1.69 acres below the 3740
OHWM of, and 0.86 acres of new shading to, the streams and rivers in the action area. Appendix H is 3741
an ESA analytical table that details individual Project components and their effects on listed species. 3742
3743
Gilliam Creek, the Green River, Panther Creek, and the Cedar River are the only waterbodies in the 3744
action area that contain federally listed species and that will incur temporary impacts below the 3745
OHWM. Additional temporary impacts below the OHWM stemming from construction of the Project 3746
will occur on Rolling Hills Creek, an unnamed tributary to Rolling Hills Creek, Thunder Hills Creek, 3747
and an unnamed tributary to Thunder Hills Creek. 3748
3749
Twelve wetlands will be permanently impacted by the Project: one Category II, seven Category III and 3750
four Category IV wetlands. Wetlands 24.7R and 25.0L are associated with Panther Creek and will 3751
experience permanent impacts of 5.42 and 0.61 acres, respectively. 3752
3753
Mitigation will be provided to compensate for the loss of wetland and stream resources within the 3754
Project area as per requirements of the Corps Section 404 permit and the WDFW HPA. Wetland and 3755
floodplain mitigation for the Project will be performed at the Springbrook Bank. A portion of the 3756
stream and river mitigation for the Project will be implemented through the PCWRP. The PCWRP is 3757
included in this BA as an element of the Project. 3758
3759
In addition to the PCWRP, additional mitigation activities are anticipated for Project impacts that will 3760
occur in the Green and Cedar Rivers. Due to a lack of foreseeable funding for the future phases of the 3761
Project that would impact these rivers, specific mitigation activities for impacts to the Green and Cedar 3762
Rivers have not been identified or defined. All mitigation activities for impacts to the Green and Cedar 3763
Rivers will be performed directly in either the Green or Cedar Rivers (based on where the impact will 3764
occur) and will be designed to mitigate for the functions lost as a result of the Project impacts. All 3765
mitigation for impacts to the Green and Cedar Rivers will be performed in accordance with the most 3766
recent version of the local critical areas at the time of construction and will compensate for lost 3767
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 112
functions. When implemented, all mitigation activities for the Project will adhere to the requirements 3768
of the applicable local, state, and federal permits obtained for the Project. Mitigation will be designed 3769
to offset wetland, stream and river functions lost as a result of Project impacts. 3770
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 113
7. References 3771
Baldwin D.H., J.F. Sandahl J.S. Labenia and N. L. Scholz. 2003. Sublethal effects of copper on coho 3772
salmon: impacts on non-overlapping receptor pathways in the peripheral olfactory nervous 3773
system. Environmental Toxicology and Chemistry 22: 2266-2274. 3774
3775
Battelle Memorial Institute (Battelle). 2006. Impacts of Ferry Terminals and Ferry Operations on 3776
Juvenile Salmon Migrating along Puget Sound Shorelines. Prepared for WSDOT. 3777
3778
Bates, K; Barnard, R.; Heiner, B; Klavas, P.; Powers, P. 1999. Fish Passage Design at Road Culverts: 3779
A design manual for fish passage at road crossings. Washington Department of Fish and 3780
Wildlife, Habitat and Lands Program, Environmental Engineering Division. Olympia, WA. 3781
http://www.wa.gov/wdfw/hab/engineer/cm/culvertm.htm#int 3782
3783
Birtwell, I.K., G.F. Hartman, B. Anderson, D.J. McLeay, and J.G. Malick. 1984. A brief investigation 3784
of Arctic Grayling (Thymallus arcticus) and aquatic invertebrates in the Minto Creek drainage, 3785
Mayo, Yukon Territory: An area subjected to placer mining. Canadian Technical Report of 3786
Fisheries and Aquatic Sciences 1287. 3787
3788
Bjorn, T. C., and D. W. Reiser. 1991. Habitat requirements of salmonids in streams. American 3789
Fisheries Society, Special Publications 19:83-138. Bethesda Maryland. 3790
3791
Bjorn, T. C., M. A. Brusven, M. Molnau, F. J. Watts, R. L. Wallace, D. R. Neilson, M.F. Sandine, and 3792
L.C. Stuehrenberg. 1974. Sediment in streams and its effects on aquatic life. Technical 3793
Completion Report, Project B-025-IDA. University of Idaho, Water Resource Research 3794
Institute, Moscow. 3795
3796
Brusven, M. A., and K. V. Prather. 1974. Influence of stream sediments on distribution of 3797
macrobenthos. Journal of the Entological Society of British Columbia 71:25-32. Buckler, D. 3798
R., A. Witt, Jr., F. L. Mayer, and J. N. Huckins. 1981. Acute and chronic effects of kepone 3799
and mirex on the Fathead minnow. Trans. Am. Fish. Soc. 110:270-280. 3800
3801
Bullard, W. E., Jr. 1965. Role of watershed management in the maintenance of suitable environments 3802
for aquatic life. Pages 265-269 in C. M. Tarzwell, editor. Biological problems in water 3803
pollution: transactions of the third seminar. U.S. Department of Health, Education, and 3804
Welfare, Public Health Service, Cincinnati Ohio. 3805
3806
Burton, K. 2003. Cedar River Chinook Redd Surveys and Carcass Collection: A review of abundance 3807
estimates, spawn timing, spawning habitat, and population age structure. Seattle Public 3808
Utilities. Online available: http://www.seattle.gov/salmon/docs/workshop/abstracts/burton.pdf 3809
3810
Cedarholm, C. J., L. C. Lestelle, B. G. Edie, D. J. Martin, J. V. Tagart, and E. O. Salo. 1978. The 3811
effects of landslide siltation on the salmon and trout resources of Stequaleho Creek and the 3812
main Clearwater River, Jefferson County, Washington, 1972-1975. Final report - Part II. Fish. 3813
Res. Inst., Univ. Washington, Seattle, WA, FRI-UW-7804, 53 p. 3814
3815
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 114
Cooper, A. C. 1959. Discussion of the effects of silt on survival of salmon eggs and larvae. Pages 18-3816
22 in proceedings of the fifth symposium-Pacific Northwest on siltation-its source and effects 3817
on aquatic environment. U.S. Department of Health, Education and Welfare, Portland, Oregon. 3818
3819
Cooper, A. C. 1965. The effects of transported stream sediments on the survival of sockeye and pink 3820
salmon eggs and alevins. Bulletin 18. International Pacific Salmon Fisheries Commission, 3821
New Westminster, British Columbia, Canada. 3822
3823
Cordone, A. J., and D. W. Kelley. 1961. The influences of inorganic sediment on the aquatic life of 3824
streams. California Fish and Game 47:189-228 3825
3826
Cordone, A. J., and S. Pennoyer. 1960. Notes on silt pollution in the Truckee River Drainage. Inland 3827
Fisheries Administrative Report 60-14. State of California, California Fish and Game, 3828
Sacramento. 3829
3830
DeVore, P.W., L.T. Brooke, and W.A. Swenson. 1980. The effects of red clay turbidity and 3831
sedimentation on aquatic life in the Nemadji River system. Impact of nonpoint pollution 3832
control on western Lake Superior. S. C. Andrews, R. G. Christensen, and C. D. Wilson. 3833
Washington, D.C., U.S. Environmental Protection Agency. EPA Report 905/9-79-002-B. 3834
3835
Environmental Protection Agency (EPA). 1980. Ambient water quality criteria for copper. U.S. 3836
Environmental Protection Agency, Publication 440/5-80-036. 162 pp. EPA. 1983. Results of 3837
the Nationwide Urban Runoff Program. NTIS No. PB84-185545. 3838
3839
Federal Emergency Management (FEMA). 2001. Flood Hazard Mapping Monthly Activities 3840
Summary Reports. October 31, 2001. 3841
3842
Fuerstenberg, R.R., K. Nelson, and R. Blomquist. 1996. Ecological conditions and limitations to 3843
salmonid diversity in the Green River, Washington U.S.A. King County Surface Water 3844
Management, Bellevue, WA. 3845
Governor's Watershed Enhancement Board (GWEB). 1997. Oregon Watershed Assessment Manual. 3846
October 1997 draft. NonPoint Source Solutions. 255 Capitol St. NE, Salem, OR. 3847
Hansen, J.A., P.G. Welsh, J. Lipton and M.J. Suedkamp. 2002a. The effects of long-term cadmium 3848
exposure on the growth and survival of juvenile bull trout (Salvelinus confluentus). Aquatic 3849
Toxicology. Pp 165-174. 3850
3851
Harris, C. M. 1991. Handbook of Acoustical Measurements and Noise Control McGraw-Hill, New 3852
York 3853
3854
Hayes, B.D., Marhaba, T.F., Agnoli, N.W., and Lackey, D.M. 1996. Evaluation of Highway Runoff 3855
Pollution Control Devices. Final Report Task Order #43, Project 7620, New Jersey department 3856
of Transportation. 3857
3858
Herbert, D. W., J. S. Alabaster, M. C. Dart, and R. Lloyd. 1961. The effect of china-clay wastes on 3859
trout streams. International Journal of Air and Water Pollution 5:56-74. 3860
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 115
3861
Herrera Environmental Consultants (Herrera). 2004. Green Duwamish River Watershed Water 3862
Quality Assessment Years 2001-2002 Data Analysis. 3863
3864
Integrated Streambank Protection Guidelines (ISPG). 2002. Washington State Aquatic Habitat 3865
Guidelines Program. A joint program comprising Washington Department of Fish and 3866
Wildlife, Washington Dept. of Ecology, and Washington State Dept. of Transportation. 3867
3868
Kerwin, J. 2001. Salmon and Steelhead Habitat Limiting Factors Report for the Cedar – Sammamish 3869
Basin (Water Resource Inventory Area 8). Washington Conservation Commission. Olympia, 3870
WA 3871
3872
Kerwin, John and Nelson, Tom S. (Eds.). 2000. Habitat Limiting Factors and Reconnaissance 3873
Assessment Report, Green/Duwamish and Central Puget Sound Watersheds (WRIA 9 and 3874
Vashon Island). Washington Conservation Commission and the King County Department of 3875
Natural Resources. 3876
3877
King County Department of Public Works. 1993. Cedar River Current and Future Conditions Report. 3878
King County Department of Public Works, Surface Water Management Division, Seattle. 3879
3880
King County Department of Natural Resources (King County DNR). 2007a. King County 3881
Department of Natural Resources. 1979-2004 Trend Table. 3882
http://dnr.metrokc.gov/wlr/waterres/streamsdata/reports/trends.pdf. Accessed March 16, 2007. 3883
3884
King County DNR. 2007b. King County Department of Natural Resources. Cedar River Site X438. 3885
http://dnr.metrokc.gov/wlr/waterres/streamsdata/Chart.aspx?Locator=X438. Accessed March 3886
16, 2007. 3887
3888
Koellmann, Derek and Bryan Patterson. 2005. Anchor Environmental, L.L.C. Personal observations 3889
during I-405 Renton Nickel Improvement Project Stream Surveys, April-June, 2005. 3890
3891
LaLonde. September 2005. Personal communication between Ginette LaLonde of Jones & Stokes and 3892
Derek Koellmann of Anchor Environmental, L.L.C. 3893
3894
Lloyd, D.S. 1987. Turbidity as a water quality standard for salmonid habitats in Alaska. North 3895
American Journal of Fisheries Management 7:34-45. 3896
3897
McHenry, M. L., D. C. Morrill, and E. Currence. 1994. Spawning gravel quality, watershed 3898
characteristics and early life history of coho salmon and steelhead in five North Olympic 3899
Peninsula watersheds. Prepared by the Lower Elwha S’Kallan tribe and the Makah Tribe, Port 3900
Angeles WA. 3901
3902
McNeil, W. J., and W. H. Ahnell. 1964. Success of pink salmon spawning relative to size of 3903
spawning bed materials. Special Scientific Report-Fisheries 469. U.S. Department of the 3904
Interior, Fish and Wildlife Service, Washington, D.C. 3905
3906
National Marine Fisheries Service (NMFS). 1999. Endangered and threatened species: threatened 3907
status for three Chinook salmon ESUs in Washington and Oregon, and Endangered status for 3908
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 116
one Chinook salmon ESU in Washington. Final Rule. Federal Register 63(56):14308-14328. 3909
(National Marine Fisheries Service). March 24, 1999. 3910
3911
NMFS. 1998. Endangered and threatened species: Proposed endangered status for two Chinook 3912
salmon ESUs and proposed threatened status for five Chinook salmon ESUs; proposed 3913
redefinition, threatened status, and revision of critical habitat for one Chinook salmon ESU; 3914
proposed designation of Chinook salmon critical habitat in California, Oregon, Washington, 3915
Idaho. Federal Register 63 (45): 11482-11520. (National Marine Fisheries Service). March 9, 3916
1998. 3917
3918
NMFS. 2005c. Biological Opinion for the SR524 widening project. Lacey, Washington. 98 pp. 3919
3920
NMFS. 2005d. Biological Opinion for the Lexington Bridge Project. Lacey, Washington. 52 pp. 3921
3922
NMFS. 2006. Biological Opinion: -405 Congestion Relief and Bus Rapid Transit Projects - Renton 3923
Nickel Improvement Project. Tracking Number 2005/06240. September 20, 2006. 3924
3925
Nuttall, P. M., and G. H. Bilby. 1973. The effect of china-clay wastes on stream invertebrates. 3926
Environmental Pollution 5:77-86. 3927
3928
Petersen, J.A., and D.M. Gadomski. 1994. “Light-Mediated Predation by Northern Squawfish on 3929
Juvenile Chinook Salmon.” Journal of Fish Biology, volume 45, pages 227-242. 3930
3931
PFMC (Pacific Fishery Management Council). 1999. Identification and Description of Essential Fish 3932
Habitat, Adverse Impacts and Recommended Conservation Measures for Salmon. Amendment 3933
14 to the Pacific Coast Salmon Plan, Appendix A. PFMC. Portland, Oregon. 3934
3935
Rand, G. M. and S. R. Petrocelli, editors. 1985. Fundamentals of aquatic toxicology: methods and 3936
applications. Hemisphere Publishing Corporation, Washington D.C. 3937
3938
Reed, R. D., and S. T. Elliot. 1972. Effects of logging on Dolly Varden. Project F-9-4, Job RV- B. 3939
Alaska Department of Fish and Game, Federal Aid in Fish Restoration, Division of Sport 3940
Fisheries, Juneau, Alaska. 3941
3942
Regional Transportation Investment District (RTID) 2007. Draft Blueprint for Progress. [Online] 3943
Available: http://www.rtid.org/docs/BlueprintFactSheet01-26-07.pdf. January 26,2007. 3944
3945
Renton, City of. 2007. City of Renton Code - Title IV - Development Regulations - [Online] 3946
Available:http://www.codepublishing.com/wa/renton/ 3947
3948
Servizi, J.A., and Martens, D.W. 1991. Effects of temperature, season, and fish size on acute lethality 3949
of suspended sediments to coho salmon. Canadian Journal of Fisheries and Aquatic Sciences 3950
49:1389-1395. 3951
3952
Scannell, P.O. 1988. Effects of elevated sediment levels from placer mining on survival and behavior 3953
of immature Arctic Grayling. Alaska Cooperative Fishery Unit, University of Alaska. Unit 3954
Contribution 27. 3955
3956
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 117
Schueler, T.R. 1987. Controlling Urban Runoff: A practical manual for planning and design of urban 3957
BMPs. Metropolitan Washington Council of Governments, Washington, D.C. 3958
3959
Sigler, J.W., T.C. Bjornn, and F.H. Everest. 1984. Effects of chronic turbidity on density and growth 3960
of steelheads and coho salmon. Transactions of the American Fisheries Society 113: 142-150. 3961
1984. 3962
3963
Spence, B.C, G.A. Lomnicky, R.M. Hughes, R.P. Novitzki. 1996. An Ecosystem approach to 3964
salmonid conservation. TR-4501-96-6057. ManTech Environmental Research Services Corp., 3965
Corvallis, Oregon. (December 1996). 3966
http://www.nwr.noaa.gov/1habcon/habweb/habguide/ManTech/front.htm 3967
3968
Stalmaster, M.V. and J.R. Newman. 1979. Perch-site preferences of wintering bald eagles in 3969
northwest Washington. Journal of Wildlife Management. 43:221-224. 3970
3971
Suckley, G., and J. G. Cooper. 1860. The natural history of the Washington and Oregon territory. 3972
Bailliere Brothers, New York. 399 pp. 3973
3974
Tukwila, City of. 2007. Tukwila Code Chapter 18.45 - Environmentally Sensitive Areas - [Online] 3975
Available:http://www.ci.tukwila.wa.us/tmc/tmc.pdf) 3976
3977
Tukwila, City of. 2001. Gilliam Creek Basin Stormwater Management Plan. Consultant Report 3978
prepared for the City of Tukwila by Herrera Environmental Consultants. Tukwila Department 3979
of Public Works, Tukwila, WA. 44 p. 3980
3981
Tukwila, City of. 1991. Black River Water Quality Management Plan. 3982
3983
U.S. Army Corps of Engineers (USACE) and Port of Oakland. 1998. Oakland Harbor Navigation 3984
Improvement [-50 foot] Project Environmental Impact Statement 1998- 3985
http://www.50ftdredge.com/EIS/ EIS_5.8.html 3986
3987
U.S. Environmental Protection Agency (EPA). 1974. Information on Levels of Environmental Noise 3988
Requisite to Protect Public Health and Welfare with an Adequate Margin of Safety. Report 3989
Number 550/9-74-004. 3990
3991
U.S. Fish and Wildlife Service (USFWS). 2004. Draft Recovery Plan for the Coastal-Puget Sound 3992
Distinct Population Segment of Bull Trout (Salvelinus confluentus). Volume I (of II): Puget 3993
Sound Management Unit. Portland, Oregon. 389 + xvii pp. 3994
3995
USFWS. 1986. Recovery plan for the Pacific bald eagle. U.S. Fish and Wildlife Service, Portland, 3996
Oregon. 160 pp. 3997
3998
Washington State Department of Ecology (Ecology). 2001. Water Quality Program. Stormwater 3999
Management Manual for Western Washington. Publication number 99-12. 175p. 4000
4001
Ecology. 2006. Washington Administrative Code. Chapter 173-201A. Water quality standards for 4002
surface waters of the state of Washington. Last Update 11/20/06. 4003
4004
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 118
Ecology. 2007. Washington State Final Integrated Report 2002/2004 [303(d) and 305(b) Report]. 4005
[Online] Available http://www.ecy.wa.gov/programs/wq/303d/2002/2002-index.html. 4006
Accessed March 16, 2007. 4007
4008
Washington State Department of Fish and Wildlife (WDFW). 2005. Priority Habitats and Species 4009
maps. Olympia, Washington. 4010
4011
Washington State Department of Transportation (WSDOT). 1994. Field note sound level 4012
measurements, Friday Harbor Wingwall Replacement, December 1994. 4013
4014
WSDOT. 2002a. I-405 Corridor Program NEPA/SEPA Final Environmental Impact Statement and 4015
Final Preliminary Section 4(f) Evaluation. June 2002. 4016
4017
WSDOT. 2002b. Record of Decision for the I-405 Corridor Program NEPA/SEPA 4018
Final Environmental Impact Statement. 4019
4020
WSDOT. 2004. Land Use Analysis – A Supporting Document to Endangered Species Act Review of 4021
the I-405 Congestion Relief and Bus Rapid Transit Projects. 4022
4023
WSDOT. 2005a. Highway Runoff Manual Post-publication Updates. [Online] Available 4024
http://www.wsdot.wa.gov/environment/wqec/docs/PostPub_HRM_Table2.5_120604.PDF. 4025
4026
WSDOT. 2005b. Draft Fisheries and Aquatic Resources Discipline Report, Renton Nickel 4027
Improvement Project. July 2005. 4028
4029
WSDOT. 2005c. Draft Noise Discipline Report, Renton Nickel Improvement Project. July 2005. 4030
4031
WSDOT. 2006a. Highway Runoff Manual M31-16. Olympia, WA. WSDOT Engineering and 4032
Regional Operations Division, Environmental and Engineering Programs, Headquarters 4033
Environmental Affairs and Hydraulics. 4034
4035
WSDOT. 2006b. BA Writers Guidance for Preparing the Stormwater Section of Biological 4036
Assessments. [Online] Available: http://www.wsdot.wa.gov/NR/rdonlyres/634BEB16-F5B2-4037
4DDE-B0CB-4BCF1D8F478B/0/BA_StormwaterGuidance.pdf. November 13, 2006. 4038
4039
WSDOT. 2006c. Hydraulics Manual M23-03. Olympia, WA. WSDOT Engineering and Regional 4040
Operations Division, Environmental and Engineering Programs, Headquarters Environmental 4041
Affairs and Hydraulics. 4042
4043
WSDOT. 2006d. MGSFlood Modeling performed by WSDOT for the Cedar River, King County, 4044
Washington. 4045
4046
WSDOT. 2007. Draft Noise Discipline Report, Tukwila to Renton Improvement Project. January 4047
2007. 4048
4049
WSDOT and Ecology. 1998. Implementing agreement between the Washington State Department of 4050
Transportation and the Washington State Department of Ecology regarding the compliance 4051
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) 119
with the state of Washington surface water quality standards. February 13, 1998. Available at: 4052
http://www.wsdot.wa.gov/environmental/Programmatics/docs/impagfin.pdf 4053
4054
WSDOT and WDFW. 2002. Memorandum of Agreement Between Washington State Department of 4055
Fish and Wildlife and Washington State Department of Transportation Concerning 4056
Construction of Projects in State Waters (Chapter RCW 77.55. RCW and Chapter 220-110 4057
WAC). June, 2002. Available online at: http://www.wsdot.wa.gov/NR/rdonlyres/E16533C3-4058
11B0-41DE-9BF3-7484C3BDECA2/0/MOA_ProjectsStateWaters.pdf 4059
4060
WSF (Washington State Ferries). 2000. Technical memorandum, Ambient Noise and the Potential 4061
Impacts of Pile Driving on Bald Eagles. August 28, 2000. 4062
4063
Wickett, W. P, 1958. Review of certain environmental factors affecting the production of pink and 4064
chum salmon. Journal Fisheries Research Board of Canada 15:1103-1126. 4065
4066
Williams, W.R., R.M. Laramie, and J.J. Ames. 1975. A catalog of Washington streams and salmon 4067
utilization. Volume 1: Puget Sound Region. Washington Department of Fisheries. 4068
4069
Young, G. K., Stein, S., Cole, P., Krammer, T., Graziano, F., and Bank, F. 1996. Evaluation and 4070
Management of Highway Runoff Water Quality. Publication No. FHWA-PD-96- 032, Federal 4071
Highway Administration, Washington, D.C 4072
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) A-1
Appendix A Draft Panther Creek Watershed 4073
Rehabilitation Plan (PCWRP) 4074
4075
4076
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING 1
TEAM (MAPT) REVIEW 2
I-405 Water Resource Initiative at the Panther Creek Wetlands 3
I-405, I-5 to SR 169 Master Plan 4
PANTHER CREEK WATERSHED REHABILITATION PLAN 5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
May 2007
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING 25
TEAM (MAPT) REVIEW 26
I-405 Water Resource Initiative at the Panther Creek Wetlands 27
I-405, I-5 to SR 169 Master Plan 28
PANTHER CREEK WATERSHED REHABILITATION PLAN 29
30
31
32
33
34
Prepared for 35
WSDOT 36
37
38
39
40
Prepared by 41
I-405 Team 42
43
44
45
May 2007 46
47
48
WSDOT Acknowledgements 49
The following team members contributed to this work: 50
Allison Ray – I-405 Environmental Management Oversight 51
Alan Black – I-405 Drainage Engineering Oversight 52
Dale Anderson – Project Manager 53
Jon Gage – Assistant Project Manager and Primary Author - Concept Plan & Habitat Improvements 54
Barb Kittel – Senior Editor 55
Greg Konkel – GIS Analyst 56
Technical Assistance provided by: 57
Anthony Stirbys – Geotechnical Investigations 58
Derek Koellmann, Paul LaRiviere, Matthew Gray, Jack Bjork – Fish Passage & Fisheries 59
Larry Karpack, Andre Ball – Hydrologic Modeling/Water Surface Elevations 60
Mark Matthies & Torrey Luiting – Wetlands 61
Ralph Nelson & Michael Gisebert – Hydrology/Hydraulics Review 62
Terry Drochak - Permitting 63
Appreciation is expressed to the following City of Renton Staff for their participation: 64
Ron Straka 65
Allen Quynn 66
67
68
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
TABLE OF CONTENTS
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan i
T ABLE OF C ONTENTS 69
Glossary............................................................................................................................................................iii 70
Acronyms.........................................................................................................................................................vii 71
Introduction .......................................................................................................................................................1 72
What is the I-405, I-5 to SR 169 Master Plan? ...............................................................................................1 73
What is an I-405 Water Resource Initiative?...................................................................................................1 74
What is this specific Water Resource Initiative for the I-405, I-5 to SR 169 Master Plan?.............................2 75
What are the key points of this Concept Plan?...............................................................................................4 76
Purpose.......................................................................................................................................................4 77
Benefits and Costs of Plan Implementation................................................................................................4 78
What are the implementation/permitting considerations?...............................................................................6 79
Schedule considerations.............................................................................................................................7 80
Existing Conditions ..........................................................................................................................................9 81
What watershed is being studied?..................................................................................................................9 82
What are the limiting factors in the watershed?..............................................................................................9 83
What is the current status of wetlands?........................................................................................................11 84
Panther Creek Wetlands west of SR 167 .................................................................................................12 85
Panther Creek Wetlands east of SR 167..................................................................................................12 86
What are the constraints to stream rehabilitation within the Panther Creek Wetlands?...............................17 87
What is the current status of the streams & fish habitat in the watershed areas proposed by this concept 88
plan?..............................................................................................................................................................18 89
Springbrook Creek....................................................................................................................................18 90
Panther Creek...........................................................................................................................................20 91
East Fork – Downstream of SR 167 .........................................................................................................20 92
East Fork - upstream of SR 167 (South Wetland)....................................................................................22 93
West Fork – downstream of SR 167.........................................................................................................23 94
Rolling Hills Creek.....................................................................................................................................24 95
Thunder Hills Creek ..................................................................................................................................25 96
What is the current status of water quality in Panther and Springbrook Creeks? ........................................27 97
What is the current status of stream flow diversions in the watershed?.......................................................28 98
What is the current status of wildlife in the watershed areas proposed by this concept plan?.....................28 99
Concept Development....................................................................................................................................31 100
What are the I-405 improvements that this concept plan addresses?..........................................................31 101
What are the stream and wetland effects? ...................................................................................................32 102
What objectives are proposed to rehabilitate streams and fish habitat? ......................................................33 103
Stream Rehabilitation 1 (SR1)..................................................................................................................34 104
Stream Rehabilitation 2 (SR2)..................................................................................................................40 105
Stream Rehabilitation 3 (SR3)..................................................................................................................40 106
Stream Rehabilitation 4 (SR4)..................................................................................................................42 107
Stream Rehabilitation 5 (SR5)..................................................................................................................42 108
Stream rehabilitation summary.................................................................................................................43 109
What objectives are proposed for associated floodplain improvements?.....................................................44 110
North Wetland...........................................................................................................................................44 111
South Wetland...........................................................................................................................................44 112
Floodplain Improvements summary..........................................................................................................46 113
What objectives are proposed for surface water?.........................................................................................47 114
How does this plan fit into the context of other watershed projects?............................................................52 115
What are the benefits and costs of implementing this concept?...................................................................53 116
What is the permitting strategy for this plan?................................................................................................54 117
What are the next steps to move forward? ...................................................................................................56 118
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TABLE OF CONTENTS
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan ii
References.......................................................................................................................................................57 119
Published Documents ...................................................................................................................................57 120
Personal Communications............................................................................................................................59 121
122
123
Appendices 124
A. Preliminary Geotechnical Investigation 125
B. Fish Habitat Memoranda 126
C. Green-Duwamish G.I. Ecosystem Restoration Feasibility Study – Project Description for Lower 127
Springbrook Reach 128
D. Hydraulic and Hydrologic Analyses Memoranda 129
E. Planning-Level Cost Estimate 130
F. Memorandum on Wetlands 131
132
E XHIBITS 133
Exhibit 1. Project Vicinity Map.........................................................................................................................3 134
Exhibit 2. Benefits of the PCWRP as related to salmonid limiting factors in Panther Creek/Springbrook Creek135
.................................................................................................................................................................5 136
Exhibit 3. Panther Creek Wetlands Existing Conditions and Planned City Trails (City of Renton, 1990 and 137
1992)......................................................................................................................................................13 138
Exhibit 4. Stream Reaches Evaluated for this Project..................................................................................19 139
Exhibit 5. Stream Habitat Conditions Summary............................................................................................26 140
Exhibit 6. 2001 and 2002 Springbrook Creek and Panther Creek median base flow water quality values .27 141
Exhibit 7. Potential Stream Effects From Master Plan Footprint...................................................................32 142
Exhibit 8. Potential Wetland Effects From Master Plan Footprint.................................................................33 143
Exhibit 9. Concept Plan.................................................................................................................................35 144
Exhibit 10. Concept Plan Enlargement.........................................................................................................37 145
Exhibit 11. Summary of Proposed Stream Rehabilitation.............................................................................43 146
Exhibit 12. Typical Panther Creek Wetland Cross Section A-A....................................................................45 147
Exhibit 13. Summary of Associated Floodplain Improvements.....................................................................46 148
Exhibit 14. Predicted Average Monthly Panther Creek Stream Flows Entering the South Panther Creek 149
Wetland for Current Conditions Compared to the Recommended Flow Management Strategy...........48 150
Exhibit 15. Predicted Surface Water Elevations in the Panther Creek Wetland for Different Flood Flows for 151
Baseline (Existing) Conditions versus the Recommended Flow Management Strategy.......................49 152
Exhibit 16. Benefits of the PCWRP as related to salmonid limiting factors in Panther Creek/Springbrook 153
Creek .....................................................................................................................................................54 154
155
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GLOSSARY
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan iii
G LOSSARY 156
100-year flood event A flood having a 1-percent chance of occurring in any given year.
alluvial fan An area of major sediment deposition, formed where a stream rapidly loses its transporting ability
because of either an abrupt reduction in slope or a sudden change from a confined to unconfined
channel, leading to flow divergence.
anadromous fish A fish species that spends a part of its life cycle in the sea and returns to freshwater streams to
spawn (reproduce). Examples of anadromous species include salmon and steelhead trout.
bankfull width The width of the stream channel between the top of the streambanks where, under high flow
conditions, the water level would be even with the top of the banks, or in a floodplain river, at the
point just before water would spill over onto the floodplain.
base flood A flood having a 1-percent chance of occurring in any given year; also called the 100-year flood.
base flow Base flow refers to the volume of flow in a stream or river during dry conditions, as opposed to
conditions influenced by storm runoff. The portion of a stream’s flow that comes from the
groundwater.
best management practice Best management practices, referred to commonly as BMPs, are methods used to minimize or
avoid effects to water quality such as sediment getting into streams during construction.
Examples of BMPs include installing filter fabric fence downstream of all exposed slopes, around
existing drainage inlets, and along river, stream, and drainage channels near work areas to
prevent sediment-laden stormwater from entering streams.
box culvert A concrete box structure that drains open channels, swales, or ditches under a roadway or
embankment.
buffer A designated area along and adjacent to a stream or wetland that may be regulated to control
the negative effects of adjacent development on the aquatic resource.
compensatory floodplain
storage
The removal of material from a site in the same floodplain and at the same elevation to
compensate for the placement of any fill within the limits of the regulatory floodplain.
construction footprint The physical area impacted by project construction activities.
critical areas Critical areas include both hazard areas (such as floodplains and steep slopes) and
environmentally sensitive areas (like wetlands and streams). Critical areas also include areas
that are important for protecting groundwater. The state Growth Management Act requires
counties to protect the “functions and values” of critical areas. Examples of wetland functions
are filtering out pollutants, providing wildlife habitat, controlling floods, and recharging
groundwater.
critical habitat Under the Endangered Species Act, (1) the specific areas within the geographic area occupied
by a federally listed species on which are found physical and biological features essential to the
conservation of the species, and that may require special management considerations or
protection; and (2) specific areas outside the geographic area occupied by a listed species when
it is determined that such areas are essential for the conservation of the species.
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GLOSSARY
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan iv
culvert A concrete structure that drains open channels, swales, or ditches under a roadway or
embankment.
ecosystem Community of organisms interacting with each other, and the environment in which they live.
emergent wetlands Wetlands comprised of plants that are rooted below the water but have foliage that extends out
of the water.
erosion The wearing away of soil or rock by the action of running water, wind, ice, or geologic agents.
For this report, erosion relates primarily to stormwater runoff.
fill Fill refers to materials placed to construct structures within waters of the United States, including
streams and wetlands. Fill materials can be rock, sand, or dirt.
floodplain The total area subject to inundation by a flood, including the floodway.
flow rate The volume of water that moves past a particular point in one second. The flow rate is measured
in cubic feet per second.
fluvial geomorphology
Refers to “Geomorphology” which is the science of the shape of the earth’s surface, the
processes that mold this surface, and consequently, how the surface will change its shape over
time. More specifically, “fluvial geomorphology” is the study of landform evolution related to
stream systems. As an integrative field it includes the related disciplines of geology, hydrology
and hydraulics, sediment transport, soil mechanics, and the mechanical effects of vegetation.
hydroperiod The period of time that a wetland is covered by water.
hydric soil Soils that develop anaerobic (absence of oxygen) conditions under persistently wet conditions.
hydrology The science dealing with the properties, distribution, and circulation of water.
hydrophytic vegetation Vegetation that is able to grow and thrive under wet soil conditions.
impervious surface Surfaces through which water cannot percolate such as pavement, roofs, and compacted or
hardened surfaces.
large woody debris Coniferous or deciduous logs, limbs, or root wads 12 inches or larger in diameter and a length of
at least 6.5 feet that intrude into or bridge above a stream channel.
nutrient Essential chemicals needed by plants and animals for growth, such as phosphorus.
ordinary high water mark The line on the shore established by the change in water levels and indicated by physical
characteristics such as a clear, natural line impressed on the bank or the presence of litter and
debris. The presence and action of water generally leaves an impression on the stream bed and
banks that makes a distinct separation between the stream and the adjacent areas and indicates
the location of the ordinary high water mark.
palustrine In the USFWS classification system, freshwater areas (having less than 0.5 parts per thousand
ocean-derived salts) dominated by trees, shrubs, persistent emergents, mosses, or lichens.
These areas can be tidal (waters which alternate by rising and falling) or non-tidal. Palustrine
also includes wetlands lacking this vegetation but having the following characteristics: (1) area
less than 20 acres; (2) no active wave-formed or bedrock shoreline; (3) deepest water depth is
less than 6.6 feet at low water.
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GLOSSARY
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan v
palustrine emergent (PEM) In the USFWS classification system, a wetland characterized by erect, rooted, non-woody plants
such as cattails, rushes, and sedges.
palustrine forested (PFO) In the USFWS classification system, a wetland characterized by woody vegetation that is 20 feet
tall or taller.
palustrine scrub-shrub (PSS) In the USFWS classification system, areas dominated by woody vegetation less than 20 feet tall,
such as trees, shrubs or young trees that are stunted due to environmental conditions.
peak flow Peak flow refers to a specific period of time when the discharge of a stream or river is at its
highest point. The maximum instantaneous rate of flow during any given storm. For this report,
peak flow refers to the 100-year storm event.
refuge habitat An area of a stream that provides shelter or safety for aquatic species.
riparian corridor The land and the vegetation community directly adjacent to (or surrounding) a natural or artificial
waterway including streams, rivers, wetlands and lakes.
riparian habitat The aquatic and terrestrial habitat adjacent to streams, lakes, estuaries, or other waterways.
Riparian habitat areas are also commonly referred to as riparian buffers.
salmonid Any member of the family Salmonidae, which includes all species of salmon, trout, and char
(including bull trout).
scrub-shrub wetlands Wetlands dominated by woody vegetation less than 20 feet tall. Vegetation in scrub-shrub
wetlands includes tree shrubs, young trees, and trees or shrubs that may be stunted because of
environmental conditions. Scrub-shrub wetlands are flooded for extended periods during the
growing season.
sediment Material that originates from weathering and erosion of rocks, dirt, or unconsolidated deposits
and organic material. Sediment travels through the movement of water, particularly stormwater
runoff and is usually suspended within the water.
sedimentation Particles deposited or settling out of the water column and forming sediment on the bed of a
channel or water course.
side channel This is a secondary stream that splits off the main channel.
stormwater The portion of precipitation that does not naturally percolate into the ground or evaporate, but
flows overland, in channels, or in pipes into a defined surface water channel or a constructed
stormwater facility.
stormwater detention Storing stormwater in manmade facilities such as ponds and releasing the stormwater at a
controlled rate. This process helps control how much and how fast stormwater enters streams
and rivers. Controlling the flow of stormwater helps maintain existing base flood levels and
minimizes erosion of stream banks.
substrate Organic and mineral materials that form the bed of a body of water.
tributary A stream or other body of water that contributes its water to another stream or body of water.
turbidity A condition caused by suspended sediments or floating material that clouds the water and
makes it appear dark and muddy.
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GLOSSARY
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan vi
wetland Wetlands are formally defined by the U.S. Army Corps of Engineers , the U.S. Environmental
Protection Agency , the Washington Shoreline Management Act of 1971 (SMA) , and the Growth
Management Act (GMA) as:
“… those areas that are inundated or saturated by surface or groundwater at a frequency and
duration sufficient to support, and that under normal circumstances do support, a prevalence of
vegetation typically adapted for life in saturated soil conditions. Wetlands generally include
swamps, marshes, bogs, and similar areas.”
The SMA and the GMA definitions add:
“Wetlands do not include those artificial wetlands intentionally created from non-wetland sites,
including, but not limited to, irrigation and drainage ditches, grass-lined swales, canals, detention
facilities, wastewater treatment facilities, farm ponds, and landscape amenities, or those
wetlands created after July 1, 1990 that were unintentionally created as a result of the
construction of a road, street, or highway. Wetlands may include those artificially-created
wetlands intentionally created from non-wetland areas to mitigate the conversion of wetlands.”
wetland boundary The point on the ground at which a shift from wetlands to nonwetlands or aquatic habitat occurs.
These boundaries usually follow topographic contours.
wetland hydrology The presence of water during a portion (between 5 and 12.5 percent) of the annual growing
season.
157
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ACRONYMS
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan vii
A CRONYMS 158
BMP best management practice
BNSF Burlington Northern Santa Fe
BRPS Black River Pump Station
cfs cubic feet per second
Corps U.S. Army Corps of Engineers
DNR Washington State Department of Natural Resources
DO dissolved oxygen
EA Environmental Assessment
Ecology Washington State Department of Transportation
ESA Endangered Species Act
ESGRWP East Side Green River Watershed Project
FAA Federal Aviation Administration
GMA Growth Management Act
GP general-purpose
HOV high occupancy vehicle
HRM Highway Runoff Manual
I Interstate
KCDD1 King County Drainage District 1
KCDNR King County Department of Natural Resources
LF linear feet
LWD large woody debris
NB Northbound
nhc northwest hydraulic consultants
NMFS National Marine Fisheries Service
OHWM ordinary high water mark
PCW Panther Creek wetlands
PCWRP Panther Creek Watershed Rehabilitation Plan
PEM palustrine emergent
PFO palustrine forested
PSS palustrine scrub-shrub
ROW right-of-way
RTID Regional Transportation Improvement District
SB Southbound
SMA Shoreline Management Act
SR State Route
TSS total suspended solids
USFWS U.S. Fish and Wildlife Service
WDFW Washington State Department of Fish and Wildlife
WRIA Water Resource Inventory Area
WSDOT Washington State Department of Transportation
159
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I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan viii
160
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INTRODUCTION
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 1
I NTRODUCTION 161
What is the I-405, I-5 to SR 169 Master Plan? 162
The I-405, I-5 to SR 169 Master Plan (referred to as 163
Master Plan herein) is part of the long-term corridor 164
transportation plan for Interstate 405 (I-405). The 165
Master Plan addresses the need to improve personal 166
and freight mobility and reduce foreseeable traffic 167
congestion in the corridor, providing a transportation 168
system that is safe, reliable, and cost-effective. 169
The Master Plan is likely to be constructed in stages 170
as funding becomes available. Each stage includes 171
highway improvements that affect streams and 172
wetlands and increase the amount of impervious 173
highway surface within the existing watershed 174
landscape. 175
What is an I-405 Water Resource Initiative? 176
An I-405 Water Resource Initiative looks beyond 177
conventional approaches to stream mitigation and 178
stormwater management. 179
In regards to stream mitigation, conventional 180
approaches typically provide mitigation in the 181
immediate area of the effects and may not consider 182
the downstream or watershed context of the 183
mitigation. Mitigation in the immediate vicinity of the 184
effects may result in habitat improvements that have 185
little, if any connectivity to downstream or upstream 186
habitat in urbanized watersheds. 187
In regards to stormwater management, the 188
Washington State Department of Transportation 189
(WSDOT) has published a Highway Runoff Manual 190
(HRM) that presents stormwater management 191
approaches. The HRM includes “conventional” 192
approaches that typically use large concrete vaults or 193
roadside ponds and swales to provide stormwater 194
detention and treatment within the highway right-of-195
way (ROW). The conventional approach for highway 196
stormwater management represents a significant cost; 197
the cost is estimated to be in excess of $1 billion for 198
the I-405 Corridor. 199
The I-405 Water Resource Initiative focuses on stream 200
mitigation and stormwater management and provides 201
for: 202
What is a watershed?
A watershed is the region of land that drains
into a specified body of water, such as a river,
lake, sea, or ocean. Rain that falls anywhere
within a given body of water's watershed will
eventually drain into that body of water.
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I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 2
1. Potential efficiencies/economies of scale by 203
combining with local agency projects and/or local 204
jurisdictions; 205
2. Environmental improvements outside of the 206
immediate highway ROW; 207
3. Possibilities to integrate contributions to other 208
social goals without compromising efficiency in 209
meeting transportation goals; and 210
4. The greatest environmental benefit while spending 211
the least amount of transportation funding. 212
What is this specific Water Resource Initiative for the I-405, I-5 to 213
SR 169 Master Plan? 214
The intent of the Panther Creek Watershed 215
Rehabilitation Plan (PCWRP) is to take a look at the 216
combined effects on streams and wetlands of all I-405 217
Master Plan improvements and conduct a watershed 218
level assessment to determine appropriate stream 219
mitigation actions that can provide the most benefit to 220
the overall watershed. 221
WSDOT intends to provide wetland mitigation in this 222
portion of the I-405 Corridor by debiting credits from 223
the Springbrook Creek Wetland and Habitat Mitigation 224
Bank. 225
This PCWRP water resource initiative provides a 226
watershed stream mitigation plan for the Master Plan 227
that can be staged to match the impacts of the staged 228
highway projects. The stream mitigation is intended to 229
mitigate impacts in the Panther Creek and lower 230
Springbrook Creek sub basins. 231
Highway drainage is an important factor affecting 232
streams in the I-405 Corridor. This plan also 233
evaluates highway drainage and how it could be cost-234
effectively managed to compliment the stream 235
mitigation work. Exhibit 1 shows the watershed 236
rehabilitation plan locations. 237
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I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 3
Interurban TrailCedar River Interpretive Trail
Green River TrailBlack River
Riparian Forest
Fort
Dent
Park
Cedar
River
Park
Liberty
Park
SW 41st St
S W 3 4 t h S t
S W 2 7 t h S t
SW 16th St
Southcenter ParkwayW Valley HwyI
n
t
e
r
u
r
ban Ave SMa
p
l
e
V
alley H
w
yRainier Ave SS
W Suns e t B lvdS W 7 t h S t
S W G r a d y W a y
Lind Ave SWTUKWILA
RENTON
I-405
Northern
Project Limit
at SR 169
I-405
Southern
Project Limit
at I-5
SR 167
Southern
Project Limit
at SW 41st St
S
pri
n
g
br
ook CreekBenson Rd SSW 23rd St Talbot Rd SBenson Dr SCedar River
Thunder
Hills
C
re
e
k
Rolling
Hill
s Cr
eekPanther CreekGreen RiverPanther
Creek
Wetlands
Panther
Lake
Carr
Rd
5 405
0 0.25 0.5
Miles
Arterial Road
Freeway
Wetland
Panther Creek
Watershed Rehabilitation
Project Areas
Springbrook Creek
Subbasin
Panther Creek
Subbasin
Municipality
Lake
Stream or Drainage
Master Plan
Project Limit
238
Exhibit 1. Project Vicinity Map 239
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I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 4
What are the key points of this Concept Plan? 240
Purpose 241
The purpose of this concept plan is to identify a 242
watershed-level mitigation plan that can be 243
implemented in tandem with highway construction 244
stages by WSDOT and/or the City of Renton. 245
The Concept Plan serves as a communication tool to 246
gain support from and involve the City of Renton, 247
resource agencies, tribes, and citizens. 248
The plan identifies goals, objectives, benefits, and 249
planning-level costs. The concept plan evaluates 250
feasibility and defines design needs and challenges. 251
This document will provide a basis of design for 252
individual mitigation projects. 253
Benefits and Costs of Plan Implementation 254
The benefits of implementing this conceptual plan are 255
to provide: 256
• Stream mitigation for the I-405, I-5 to SR 169 257
Master Plan that addresses limiting factors at a 258
“watershed level.” 259
• Fish habitat improvements via stream flow 260
management to: (1) provide more reliable 261
stream base flows, (2) create stream flow 262
changes that are compatible with wetland 263
floodplain enhancement, and (3) manage 264
stream flows to be compatible with 265
downstream flood control needs. 266
• A direct discharge of treated highway 267
stormwater into the Panther Creek wetland 268
complex to provide additional project benefits. 269
A key benefit is to address the City of Renton 270
Airport Operator’s air traffic safety concern for 271
building new open-water detention facilities 272
within the I-405/SR 167 Interchange. These 273
facilities would be within a restricted area for 274
aircraft flight paths. Air traffic safety is a key 275
concern due to high costs and fatality issues 276
associated with bird strikes. The direct 277
discharge approach is also compatible with the 278
habitat mitigation proposal and more cost-279
effective than conventional stormwater 280
management. 281
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I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 5
As part of the watershed-level assessment, we 282
defined key factors that limit the production of fish, 283
specifically salmonids. Implementation of the PCWRP 284
will provide stream habitat improvements that address 285
limiting factors for salmonid production in Panther 286
Creek and a portion of Springbrook Creek. Exhibit 2 287
provides a summary of how the PCWRP addresses 288
limiting factors for salmonid production. 289
290
Exhibit 2. Benefits of the PCWRP as related to salmonid limiting factors in Panther
Creek/Springbrook Creek
Salmonid Limiting Factors
Lack of Salmonid
Refuge
Degraded Water Quality Lack of Functioning Riparian
Habitat
Fish Barriers
Establishes 0.50
acre of off-channel
rearing habitat in
Panther Creek
wetland
Cascades to be provided in
new channel design (at
alluvial fan) to provide water
aeration and improve
dissolved oxygen
concentrations in Panther
and Springbrook Creeks.
Riparian shade tree plantings
to lower summer water
temperatures
7,750 linear feet (162,000
square feet) of in-channel
improvements, including 5,350
linear feet in Panther Creek
and 2,400 linear feet in
Springbrook Creek
36.9 acres of associated
floodplain improvements to
stream buffer/wetlands
including 12.8 acres of stream
buffer restoration to left bank of
east fork Panther Creek to
provide required buffer width
Removes 3
barriers (620 LF)
to fish passage
within Panther
Creek and
connects up to 3
miles of Panther
Creek riparian
habitat for fish use
Benefits of the
Panther Creek
Watershed
Rehabilitation Plan
Enhanced water quality
treatment of WSDOT
stormwater discharged to the
Panther Creek wetland
complex
291
292
The planning level cost to implement the watershed-293
level stream mitigation plan is approximately $13.9 294
million (See Break Out). 295
The planning level cost (today’s dollar) for highway 296
improvements in this area is $1.03 billion. The 297
stormwater management (quantity and quality) portion 298
of these highway costs, using conventional practices, 299
is $46 million. The stormwater management cost 300
providing a direct discharge of treated stormwater, as 301
recommended in this PCWRP, is $29 million. 302
303
How do project costs break out?
Stream Rehabilitation $5,075,000
Floodplain Improvements $2,413,000
Fish Passage Improvements $2,115,000
Springbrook Trail $906,000
Subtotal $10,509,000
Sales Tax (8.80%) $925,000
Contingency (10%) $1,051,000
PSE & Permitting (11%) $1,373,000
Grand Total $13,858,000
Costs are today’s dollar and are approximate, based on
conceptual design.
ROW costs are not included. It is assumed the City of
Renton will provide their Panther Creek wetland
property for the project.
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I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 6
What are the implementation/permitting considerations? 304
305
• The draft PCWRP has been reviewed by the 306
City of Renton and an endorsement of the 307
Concept obtained by WSDOT. The draft 308
PCWRP will be reviewed by the Multi-agency 309
Permitting Team (MAP Team), and the 310
appropriate Tribes. Early coordination with the 311
agencies and the Tribes is critical to determine 312
their support for a watershed-level Plan that 313
could be permitted in stages as highway 314
construction stages are built. 315
• A final AGREEMENT between the City of 316
Renton and WSDOT for concept 317
implementation will need to be reached. 318
WSDOT ownership of the Concept sites is 319
limited to WSDOT right-of-way. The City of 320
Renton owns or has easements for areas 321
located within the Panther Creek wetlands. 322
• Approval for the proposed stormwater 323
management approach is needed from the 324
MAP Team. 325
• Construction stages will be identified as 326
additional funding is obtained. Stream 327
mitigation, based on the PCWRP, will be 328
identified, as practicable, for each construction 329
stage. 330
• The current stream rehabilitation area 331
estimates in this plan are preliminary and 332
conceptual. It is important to note that this 333
plan is not intended to be a stream mitigation 334
plan for permitting purposes. This is a concept 335
plan and first step toward thoughtful planning 336
for the implementation of stream mitigation 337
projects for this section of the I-405 Corridor. 338
• Stream mitigation plan reports and final 339
designs (plans, specifications and estimates) 340
are still required for the opportunities identified 341
herein for permitting requirements. 342
• Local, state, and federal permits as identified in 343
this plan will need to be obtained for each 344
construction stage. 345
• Coordination with King County Drainage 346
District No. 1 would be required for work on 347
Lower Springbrook Creek. 348
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I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 7
• Easements may be required from private 349
property owners and have not been accounted 350
for in the planning level cost estimate. 351
• WSDOT intends to provide wetland mitigation 352
in this portion of the I-405 Corridor by debiting 353
credits from the Springbrook Creek Wetland 354
and Habitat Mitigation Bank. 355
Schedule considerations 356
• WSDOT is currently preparing the 357
Environmental Assessment (EA) for the 358
Tukwila to Renton Improvement Project 359
(Tukwila to Renton). Stream mitigation for the 360
highway improvement effects on Panther 361
Creek and other tributaries to Springbrook 362
Creek will be addressed in the EA. If 363
approved, the PCWRP will be used to identify 364
stream mitigation for Tukwila to Renton effects 365
in the Panther and Springbrook sub basins. 366
Timely approval of the PCWRP by the spring 367
of 2007 will be necessary for completion of the 368
Tukwila to Renton EA, which is planned for 369
release in the fall of 2007. 370
• The first stage of Tukwila to Renton roadway 371
construction will be the I-405, I-5 to SR 169 372
Stage 2 widening and SR 515 Interchange. 373
This stage is planned for construction in late 374
2008. 375
• The HOV flyover ramps are part of the 376
Regional Transportation Improvement District 377
(RTID) funding which is pending public vote, 378
anticipated in the fall of 2007. The remainder 379
of the Tukwila to Renton highway 380
improvements and other Master Plan 381
improvements are unfunded at this time and no 382
funding timeline is set. The stream mitigation 383
for construction of the HOV flyover ramps 384
could be the first phase of implementation for 385
the PCWRP. 386
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INTRODUCTION
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 8
387
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EXISTING CONDITIONS
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 9
E XISTING C ONDITIONS 388
What watershed is being studied? 389
Panther Creek and Springbrook Creek are sub basins 390
located within the Green/Duwamish and Central Puget 391
Sound Watershed (Water Resource Inventory Area 392
[WRIA] 9). Panther Creek flows 3.4 miles from its 393
headwaters at Panther Lake to its confluence with 394
Springbrook Creek. The Panther Creek wetlands 395
(PCW) are approximately one-half mile upstream of 396
the confluence with Springbrook Creek. The creek 397
enters the wetlands east of SR 167 at the south end 398
and flows through a roadside wetland ditch and under 399
SR 167, at the SW 23rd Street culvert before its 400
confluence with Springbrook Creek. Springbrook 401
Creek drains to the Black River Pump Station (BRPS) 402
and eventually to the Green/Duwamish River. Exhibit 403
3 shows the existing conditions within the PCW to the 404
confluence with Springbrook Creek. 405
These sub basins are located within the Green River 406
Valley which has been greatly altered over the last 407
century. Historically, the extensive forested swamp 408
that covered much of the valley was cleared, diked, 409
drained, and converted to wet soil agricultural crops. 410
Rapid urbanization in the Green River Valley since the 411
mid 1960s has displaced agriculture with urban fill for 412
development.1 413
What are the limiting factors in the watershed? 414
The Panther Creek Watershed Rehabilitation Plan is 415
considered a watershed-level stream mitigation effort 416
because it considers habitat improvements throughout 417
much of the Panther Creek sub basin and in the lower 418
Springbrook Creek sub basin. 419
An important requirement of watershed-level 420
mitigation effectiveness is to understand the factors 421
limiting salmonid production within the watershed. 422
Past scientific literature was reviewed to determine 423
limiting factors for salmonid production in the 424
watershed. A key document found during this search 425
was Harza (1995), which contains a limiting factors 426
analysis for the Springbrook Creek sub basin. 427
1 P-9/Panther Creek Project Wetlands Inventory. The Coot Company. June 29, 1989.
What is a Water Resource Inventory Area
(WRIA)?
Washington State is divided into 62 WRIAs
for water and aquatic-resource management
issues. A WRIA may include more than one
watershed. However, the terms "WRIA" and
"watershed" are frequently used
interchangeably.
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I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 10
Panther Creek is a tributary to the Springbrook Creek 428
subbasin. Although the Harza report did not include 429
Panther Creek in its report scope, the analysis is 430
relevant due to the similar nature of Panther Creek to 431
other tributaries of Springbrook Creek, including 432
Garrison and Mill Creeks. In 2000, King County 433
provided a limiting factors analysis for the Springbrook 434
Creek subbasin that also references Harza (1995). 435
Harza’s work served as the basis for the 2000 report 436
to define limiting factors. The most recent effort, King 437
County, 2005, is a summary of the earlier King County 438
work. 439
The following is direct quote from King County (2000) 440
that summarizes the limiting factors analysis for the 441
Springbrook Creek subbasin: 442
• Historically, it is believed that these creeks 443
were important areas of refugia to anadromous 444
salmonids that reared year round in the Green 445
River basin. 446
• Water quality is degraded throughout much of 447
this subbasin. 448
• There is no functioning riparian habitat 449
throughout the lower reaches of Mill and 450
Springbrook Creeks. This absence of this 451
habitat contributes to the lack of stream 452
channel diversity, complexity, and ultimately 453
successful salmonid rearing capabilities. 454
• The Black River Pump Station is a partial fish 455
passage barrier and does not meet current fish 456
screening criteria. Adult salmonids that 457
migrate upstream of this structure cannot 458
migrate back into the mainstem Green River 459
because of facility design. 460
• There are several known barriers to adult 461
salmonid passage in Springbrook, Mill, and 462
Garrison Creeks. Some of these barriers are 463
seasonal and/or dependent on annual 464
precipitation patterns. 465
• Degraded water quality throughout the lower 466
reaches of Springbrook and Mill Creeks 467
adversely impact adult Chinook and coho 468
reproductive success along with cutthroat and 469
steelhead juvenile survival. 470
King County (2005) includes the Springbrook Creek 471
subbasin as a subset of the larger Lower Green River 472
subwatershed. For this larger area, the key salmon 473
habitat needs will: 474
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I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 11
• Protect and restore side channels, off-channel 475
wetlands, tributary mouths, and pools that 476
provide shelter and habitat complexity for 477
young salmon; 478
• Protect and restore natural sediment 479
movement by reconnecting sediment sources 480
to the river; 481
• Preserve groundwater inflow from the historical 482
White River channel; 483
• Modify the Black River Pump Station to 484
improve fish passage. 485
486
The above discussion of limiting factors for salmonid 487
production in the Springbrook and Lower Green River 488
subwatershed is applicable to the Panther Creek, as a 489
tributary to Springbrook Creek. Hydrologic analyses 490
conducted for this planning effort revealed low stream 491
flows in Panther Creek as another important limiting 492
factor (see Appendix C – nhc Memorandum, February 493
2006). Modeling results showed stream flows were 494
essentially 0 cubic feet per second (cfs) in the east 495
fork of Panther Creek in May through August, due to 496
the dispersed flows across the alluvial fan that has 497
formed where Panther Creek flows onto the valley 498
floor. This information is considered in the stream flow 499
management planning for concept development in the 500
next chapter. 501
What is the current status of wetlands? 502
Washington State Department of Transportation 503
(WSDOT) performed wetland reconnaissance on the 504
approximately 65-acre PCW complex. 505
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EXISTING CONDITIONS
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 12
Panther Creek Wetlands west of SR 167 506
The 6.5 acre wetland west of SR 167 is a scrub-shrub 507
wetland confined to a long, narrow depression parallel to 508
SR 167. Rated as a Category III wetland, willow, 509
Himalayan blackberry, and reed canarygrass dominate 510
the wetland. The west fork of Panther Creek flows 511
through a culvert under SR 167 and provides hydrology 512
to this wetland.2 513
Panther Creek Wetlands east of SR 167 514
The 58.5-acre wetland to the east of SR 167 is a 515
depressional wetland that is categorized as a Category 516
II under the state rating system and a Category I under 517
the City of Renton rating system.2 Historically, the 518
wetland was likely a more riverine-type associated with 519
the floodplain of Springbrook Creek and the historic 520
floodplain of the Green/Duwamish River. The creek 521
and river are now separated from the wetland by 522
levees and urbanized/industrialized floodplain 523
development. The wetland relies on seasonally 524
elevated groundwater levels, perennial flows from 525
Panther Creek east fork, and hillside drainages and 526
seeps from the Talbot Hill to the east for its hydrology.3 527
The PCW extend east from the toe of the SR 167 road 528
fill to the toe of the forested slope (Talbot Hill). An 529
Olympic gas pipeline corridor runs east-west through 530
the complex at SW 23rd Street and parallel to SR 167 531
in vicinity of SW 19th Street (Exhibit 3). The pipeline 532
corridor’s berm physically divides the wetland into two 533
areas: north and south. SR 167 limits the outflow of 534
water from the Panther Creek wetland to three 535
culverts beneath SR 167: north (SW 19th Street), 536
central (SW 23rd Street), and south (SW 34th Street). 537
538
2 I-405, Renton Nickel Improvement Project, I-5 to SR 169. Wetland Discipline Report. WSDOT. December 2005.
3 WSDOT Panther Creek Wetlands Assessment. Jones & Stokes. October 19, 2005.
What do the wetland categories mean?
Wetland categories described in the
Washington State Wetland Rating System for
Western Washington State – Revised (Hruby
2004) rate wetlands based on uniqueness,
type, and functions. These categories are
used to determine the level of mitigation
required when projects affect them. The two
categories that apply for the wetlands
covered by this plan are:
Category II wetlands provide high levels
of some functions and are difficult,
though not impossible to replace.
Category III wetlands provide moderate
levels of functions. They have been
disturbed and are often less diverse or
more isolated from other natural
resources in the landscape than
Category II wetlands.
An Olympic gas pipeline corridor divides
the Panther Creek wetlands east of SR 167
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW EXISTING CONDITIONS I-405 Water Resource Initiative at Panther Creek Wetlands Panther Creek Watershed Rehabilitation Conceptual Plan 13 PEM (Narrowleaf Cattail)Wetland 1(PF01/PEM)Wetland 2(PF01)Wetland 4(PF01)CottonwoodUplandLobePF01/PSS1Willow, Ash, Cottonwood, Dogwood, SpireaPSS1 (Willow Thicket)PSS1/PF01PEM(Cattail)UplandForestLobePSSPSSPSSPEMPSSPEM(Cattail, Canarygrass)PEM(Common Cattail)PSS1PEM(Canary-grass) PSS1(Willow Thickets)PF01(Willow,Cottonwood,ForestedWetland)Wetland 2(PF01)Wetland 3(PF01)SW 41st StPanther Creek East ForkTalbot Road SouthSW 23rd StSpringbrook CreekPanther Creek East ForkPanther CreekPanther Creek West ForkAlluvial FanNorth WetlandSouth WetlandSpringbrook Trail (I)Cascade Trail (H)Springbrook WetlandsTrail (T)Panther Creek Trail (S)W G r a d y W aLind Ave SWEast Valley RdSW 27th StSW 34th StSW 16th StSW 19th StRaymond Ave SWSW 29th StS W 1 3 t h S tSW 21st StMaple Ave SWWetland Vegetation Communities:PEM (canarygrass): palustrine emergent, monocultureof reed canarygrass.PEM (cattail): palustrine emergent, patches/monocultureof common cattail.PEM (cattail/reed canarygrass): palustrine emergent -reed canarygrass matrix with patches/areas of cattail.PSS1: palustrine scrub-shrub broad-leaved deciduousthickets of shrubby willow, with various understory species.PFO1: palustrine forested broadleaf deciduous wetlanddominated by Pacific willow trees with Oregon ash andblack cottonwood trees and dense shrub layer of shrubwillows and various other shrubs and herbs.Extent of wetland vegetation communities are approximateand based on field investigations conducted October 6th and10th, 2005 by WSDOT.0 200 400FeetLegendExisting Contour (2 FT contour interval)Utilities - Water, SewerUtilities - Gas, Oil, TelecommunicationsFAA Boundary (10,000 Feet)Streams (Open Channel)Streams (Piped)City Owned Properties/EasementsPanther Creek Wetlands (approx.)Misc. Wetlands (approx.)Planned Trails - City of Renton(1990, 1992) 539 Exhibit 3. Panther Creek Wetlands Existing Conditions and Planned City Trails (City of Renton, 1990 and 1992) 540
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW EXISTING CONDITIONS I-405 Water Resource Initiative at Panther Creek Wetlands Panther Creek Watershed Rehabilitation Conceptual Plan 14 541
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I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 15
542
The hydrologic functions the PCW perform include flood 543
flow alteration, sediment removal, nutrient and toxicant 544
removal from stormwater runoff, and erosion control and 545
shoreline stabilization. The biological functions the PCW 546
performs are production of organic matter and its export, 547
general habitat suitability, habitat for aquatic 548
invertebrates, habitat for amphibians, habitat for wetland 549
associated mammals, habitat for wetland associated 550
birds, general fish habitat. The social value for the PCW 551
is unique heritage and richness because it has been 552
identified by the City of Renton as having local 553
significance.4 554
North Wetland 555
The North Wetland covers approximately 13 acres and 556
is divided from the south wetland at SW 23rd Street. 557
This forested and scrub-shrub wetland comprises less 558
than one third of the total PCW. This portion has 559
seasonally elevated groundwater levels and likely 560
receives some overbank surface flows from Rolling 561
Hills Creek, Thunder Hills Creek, and seeps from 562
Talbot Hill. Saturated soils and areas of standing 563
water appear to be present throughout most of the 564
year. The forested and scrub-shrub communities in 565
this wetland are high quality. These wetland 566
communities are experiencing water levels that may 567
be very near their upper limits of tolerance for 568
sustaining the types of wetland vegetation currently 569
found here. This is based upon the degree of soil 570
saturation observed during October 2005 site visits 571
and our general knowledge of the physiological 572
tolerances to inundation of the plant species observed 573
on the site.5 574
The North Wetland is a mature, forested wetland 575
community dominated by dense vegetation. Species 576
include Pacific willow, Oregon ash, black cottonwood, 577
red-osier dogwood, Douglas spirea, Scouler’s/Sitka 578
willow. The eastern buffer is dominated by native 579
upland tree and shrub species. There presently is no 580
western buffer because of SR 167. 581
4 I-405, Renton Nickel Improvement Project, I-5 to SR 169. Wetland Discipline Report. WSDOT. December 2005.
5 WSDOT Panther Creek Wetlands Assessment. Jones & Stokes. October 19, 2005.
The North Wetland has dense mature
vegetation
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
EXISTING CONDITIONS
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 16
South Wetland 582
At approximately 45 acres, the South Wetland 583
comprises more than two thirds of the PCW. 584
Seasonally elevated groundwater levels, direct flow 585
from Panther Creek, and seeps and drainages from 586
Talbot Hill provide hydrology to this wetland. Two 587
primary culverts cross under SR 167 in the South 588
Wetland. The largest culvert, 72 inches in diameter, is 589
at SW 23rd Street. Saturated soils and areas of 590
standing water appear to be present throughout most 591
of the year. 592
The South Wetland has a range of wetland 593
communities. Approximately 1,200 feet south from the 594
Olympic pipeline berm is a 10-acre scrub-shrub 595
community characterized by Pacific willow and 596
Scouler’s/Sitka willow with Nootka rose and Douglas 597
spirea in small patches. Yellow-flag iris dominates the 598
understory. 599
This community abruptly changes to a 27-acre 600
emergent wetland community from SW 27th Street 601
approximately 3,400 feet southward. It is dominated 602
by reed canarygrass, common cattail, and small 603
thickets of willow/rose/spirea interspersed along the 604
eastern toe of the slope. At this point, South Wetland 605
(Exhibit 3) meets the alluvial fan for Panther Creek. 606
From here, the wetland transitions to an 8-acre 607
forested wetland community. It is dominated by 608
Pacific willow, red alder, black cottonwood trees, with 609
an understory of reed canarygrass, yellow-flag iris, 610
and some scattered native herbaceous and shrub 611
species. 612
The scrub-shrub wetland has an excellent density and 613
diversity of native scrub-shrub wetland community 614
type. The forested wetland in the extreme south end 615
has varying degrees of habitat diversity. However, the 616
large emergent wetland community, which comprises 617
almost 60 percent of the South Wetland, has low 618
habitat diversity and is dominated by monocultures of 619
reed canarygrass and common cattail.6 620
6 WSDOT Panther Creek Wetlands Assessment. Jones & Stokes. October 19, 2005.
Reed canarygrass dominates the emergent
vegetation community in the South
Wetland
What are invasive plant species and why
are they a problem?
Invasive plant species are those that do not
naturally grow in a particular area, but thrive
once introduced. These plants are adaptable
and aggressive, and they have a high
reproductive capacity. They can outcompete
native plants and take over plant
communities, disrupting the natural functions.
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EXISTING CONDITIONS
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 17
What are the constraints to stream rehabilitation within the Panther 621
Creek Wetlands? 622
The majority of PCW outside of the WSDOT right-of-623
way (ROW) are located on property owned by the City 624
of Renton as shown in Exhibit 3. The City has 625
drainage easements for the remaining parcels up to 626
elevation 20 (datum NAVD 88). Drainage easements 627
don’t preclude the rehabilitation activities proposed by 628
this plan. Further investigation is required to verify 629
that none of the parcels currently have recorded 630
easement restrictions. 631
Underground and overhead utilities bisect the 632
wetlands (east-west) at three locations. Beginning at 633
the project’s north end, the following utility crossings 634
occur: 635
• City water main at SW 19th Street 636
• Olympic Pipeline utility berm at SW 23rd Street 637
• King County Sewer line at approximately SW 638
39th Street 639
The King County sanitary sewer line is 18 inches in 640
diameter. Further investigation is required to confirm 641
location and depth of this line from Metro as-built plans. 642
The City of Renton (City of Renton 1990, 1992) has 643
planned trails in the vicinity (Exhibit 3), including: 644
major trails – Springbrook Trail (I) and the Cascade 645
Trail (H); and minor trails – Springbrook Wetlands Trail 646
(T) and the Panther Creek Trail. The City has asked 647
WSDOT to include the Springbrook Trail (I) as part of 648
this project and has also asked that this project not 649
preclude future construction of the other trails. 650
Federal Aviation Administration (FAA) guidelines 651
restrict open water areas within a 10,000-foot 652
boundary of the Renton Municipal Airfield because of 653
safety concerning aircraft encountering birds. This 654
restriction applies to those areas northward of the FAA 655
boundary shown in Exhibit 3. The boundary bisects 656
the wetlands approximately 400 feet south of SW 23rd 657
Street. 658
Slope stability analysis was conducted by WSDOT for the 659
PCW. Initial hydrologic analysis performed for this project 660
considered raising water levels 2 feet within the wetland. 661
This scenario is no longer being considered, however, the 662
geotechnical analysis for it is presented at the City of 663
Renton’s request. The Preliminary Geotechnical 664
Investigation – Panther Creek Watershed Restoration 665
Project, November 3, 2005 (Appendix A), indicates that 666
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I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 18
the slopes would be stable even if the groundwater level is 667
raised another 2 feet in the wetland. 668
What is the current status of the streams & fish habitat in the 669
watershed areas proposed by this concept plan? 670
Waterbodies located in the watershed project area 671
include Springbrook Creek, Panther Creek and its 672
associated wetland system, Rolling Hills Creek, and 673
Thunder Hills Creek. All of these streams ultimately 674
flow into the Green/Duwamish River. Exhibit 4 675
identifies the stream reaches evaluated for the 676
PCWRP. 677
Exhibit 5 summarizes the habitat conditions for the 678
stream reaches shown in Exhibit 4. The following 679
sections describe each stream. 680
Springbrook Creek 681
Springbrook Creek is the only known waterbody within 682
the watershed project area to contain Chinook salmon, 683
a species listed as threatened under the Endangered 684
Species Act (ESA). Other species listed as threatened 685
or endangered under ESA, such as bull trout and Dolly 686
Varden, are not known to occur within the watershed 687
project area. Chinook salmon critical habitat within the 688
watershed project area includes Springbrook Creek. 689
Physical conditions 690
Springbrook Creek is a receiving waterbody for 691
Panther, Rolling Hills, and Thunder Hills creeks. 692
Riparian habitat within Springbrook Creek does not 693
meet the National Marine Fisheries Service (NMFS) 694
criteria for properly functioning habitat and is 695
considered a limiting factor to natural salmonid 696
production.7 Springbrook Creek is known to be used 697
by coho salmon, Chinook salmon, cutthroat trout, and 698
steelhead trout for spawning and rearing,8 however 699
fish count information is still missing from the WRIA 9. 700
7 Salmon and Steelhead Habitat Limiting Factors Report for the Cedar – Sammamish Basin (Water Resource Inventory
Area 8), Washington Conservation Commission. Kerwin. 2001.
8 Inland fishes of Washington. Wydosky and Whitney. 1979.
What is the Endangered Species Act?
Congress passed this act in 1973 to govern
how animal and plant species whose
populations are dangerously in decline or
close to extinction will be protected and
recovered.
Springbrook Creek at confluence with
Panther Creek
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW EXISTING CONDITIONS I-405 Water Resource Initiative at Panther Creek Wetlands Panther Creek Watershed Rehabilitation Conceptual Plan 19 Gilliam CreekGilliamCreekTributaryW V AL L EY H W Y
Green RiverOAKESDALE AVE SWSpringbrook CreekPanther CreekWest ForkRolling Hills CreekP a n t h e r C r e e k
E a s t F o r k Panther CreekSE 176TH STSE CARR RDB E N S O N R D S
SW GRADY WAYRAINIER AVE ST h u n d e r H ills
C re e k
R o l l in g H i ll s C r e e k
SpringbrookCreekPanther CreekRolling HillsCreekRollingHills CreekThunder Hills Creek00.250.125MilesStreams (Piped)Stream Survey ExtentsLegendStreams (Open Channel) 701 Exhibit 4. Stream Reaches Evaluated for this Project 702 703
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I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 20
Fish passage 704
The BRPS is located upstream of the confluence 705
between Springbrook Creek and the Green/Duwamish 706
River. The BRPS controls outflows from Springbrook 707
Creek into the Black River, prevents flows on the 708
Green River from backing up into Springbrook Creek 709
during storm events, and provides a means of 710
releasing flood flows from the Springbrook Creek 711
system when the Green River has high flows as a 712
result of storms. The BRPS has been identified by the 713
Salmon Enhancement Plan9 and others as being in 714
need of fish passage improvements. A total of 262 715
upstream migrating adult salmonids were counted after 716
passing the BRPS during the 1994-1995 run. Of 717
these, 14 were Chinook salmon and 229 were coho 718
salmon. Overwintering salmonids observed during this 719
run included 84 juvenile coho salmon, 198 rainbow 720
trout and 4 cutthroat (Harza 1995). King County is 721
presently considering a proposal for fish passage 722
improvements to the BRPS which would in turn 723
improve fish passage to lower Springbrook Creek. 724
Panther Creek 725
East Fork – Downstream of SR 167 726
Physical conditions 727
Four culverts occur along the east fork of Panther Creek 728
from SR 167 to the confluence with Springbrook Creek. 729
The first culvert moving downstream, the SR 167 cross 730
culvert, is a combination fish ladder and conveyance 731
structure between the PCW and the west side of SR 167. 732
The cross culvert is about 210 feet long, and is a 72-733
inch-diameter pipe. 734
From the SR 167 cross culvert, Panther Creek flows 735
through another 72-inch-diameter pipe (approximately 70 736
feet long) under East Valley Road. This culvert outfalls 737
to an open channel system along SW 23rd Street. The 738
channel is primarily straight with few pools and limited in-739
stream structures. A significant portion of the right bank 740
of this segment of Panther Creek borders an access road 741
that limits both riparian buffer establishment and a 742
connection with the creek’s floodplain. Significant 743
portions of the left bank border are forested wetlands. 744
9 King County. 2005.
What are fish passage barriers?
Fish passage barriers prevent or limit the
ability of fish to move upstream past the
barrier. The fish passage standards
established by the Washington Department of
Fish and Wildlife in 2003 describe fish
barriers as “complete”, “temporal”, or “partial”.
Culvert outfall (underwater) under East
Valley Road to SW 23rd Street open
channel
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I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 21
Panther Creek crosses under Lind Avenue in twin arch 745
culverts that outfall to a pool. From here, Panther Creek 746
crosses under high pressure petroleum pipelines in a set 747
of culverts, a box culvert and a pipe. Installed in 1998, 748
these two culverts are 84 feet in length and are owned by 749
the Olympic Pipeline Company. From these two 750
culverts, the creek flows in an open channel with 751
significant portions of the left bank bordered by forested 752
wetlands until the creek reaches its confluence with 753
Springbrook Creek. 754
Fish passage 755
This portion of Panther Creek likely supports the same 756
species of fish as are found in Springbrook Creek. 757
The fish ladder was evaluated for only one flow (34 758
cubic feet per second (cfs)). This flow is estimated as 759
a 2-year peak storm flow. At this flow, it failed to meet 760
the suggested fish passage criteria for 3 feet of 761
freeboard, fishway bends, and depth over the weirs. 762
This structure may be a partial barrier to fish 763
passage.10 However, LaRiviere11 stated that “the fish 764
ladder appears to function as intended regarding 765
juvenile and adult fish passage; it conveys flow year 766
round, there are no drop barriers, and velocity barriers 767
are only temporal.” The 210-foot cross culvert under 768
SR 167 appears to meet Washington State 769
Department of Fish and Wildlife (WDFW) fish passage 770
requirements. 771
Compared to the WDFW fish passage criteria for high 772
flows, velocities in the East Valley Road culvert at SW 773
23rd Street are lower than the maximum allowable and 774
flow depths are greater than the minimum allowable. 775
Due to the downstream backwater, flow depths will be 776
adequate in low flow conditions. Consequently, it 777
appears that the culvert is not a barrier to fish passage 778
for a wide range of flows and no modifications are 779
needed at this time.12 780
Flow depth is adequate under low flow conditions 781
because the Olympic Pipeline culverts are submerged. 782
The velocities and depths are acceptable according to 783
the WDFW fish passage criteria for high flows. 784
However, LaRiviere10 stated that underwater culverts 785
can be partial barriers to both upstream and 786
downstream movement of fish because of the 787
10 Fish Passage at Evaluation at Central Panther Creek Outlet. WSDOT. 2006.
11 Panther Creek Fish Passage Memorandum. LaRiviere. 2006.
12 Fish Passage at Selected Panther Creek Culverts. RW Beck. 2006.
This fish ladder on Panther Creek east fork
is a partial fish passage barrier
The lower Lind Avenue culverts on Panther
Creek
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
EXISTING CONDITIONS
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 22
submergence. Relocation of the Olympic pipelines 788
would improve fish passage. However, relocation 789
would be costly, and is a low priority to improve fish 790
passage in Panther Creek.12 791
Subject to further analysis, there are no known 792
complete barriers that would preclude fish passage 793
between the confluence with Springbrook Creek and 794
the Panther Creek wetland complex.11 795
East Fork - upstream of SR 167 (South 796
Wetland) 797
Physical conditions 798
Panther Creek flows from Talbot Hill forming an 799
alluvial fan on the valley bottom in the PCW. At the 800
upstream end of the alluvial fan, Panther Creek splits 801
into two forks, hereafter referred to as the east and 802
west fork. Typical of alluvial geomorphology, Panther 803
Creek flows through this area are dynamic. WSDOT 804
reconnaissance between October 2005 and March 805
2006 observed the majority of flow shift from the east 806
fork to the west fork. Also, the alluvial fan is 807
characterized by numerous side channels, braids and 808
rivulets that change course with flood events. At the 809
confluence with the wetland, the east fork of Panther 810
Creek flows northerly through the wetland in a 811
roadside ditch along the east side of SR 167 for 812
approximately one mile before it outlets at the culvert 813
under SR 167. This portion of Panther Creek likely 814
supports the same species of fish as are found in 815
Springbrook Creek. 816
Little salmonid spawning habitat exists in Panther 817
Creek throughout most of the wetland area; however, 818
suitable spawning habitat is available upstream of the 819
alluvial fan. 820
Stream habitat in this reach is poor for the riparian 821
zone width because of proximity to the road fill on the 822
left bank as shown on Exhibit 5. 823
Fish passage 824
Panther Creek upstream of SR 167 is considered 825
accessible by fish and other aquatic species from 826
culverts under SR 167 (e.g., SW 23rd Street). Despite 827
the absence of a distinct stream channel through the 828
wetland between the fish ladder and the alluvial fan 829
area, there are no known barriers to fish passage 830
Panther Creek mainstem fork; east fork is
to left and west fork to right of photo
Panther Creek east fork upstream of
SR 167 in South Wetland
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
EXISTING CONDITIONS
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 23
within the PCW.13 Currently, fish passage in this area 831
is likely limited to flood events. 832
West Fork – downstream of SR 167 833
Physical conditions 834
The west fork of Panther Creek flows underneath 835
SR 167 in two culverts (one is the main crossing and 836
one is overflow crossing). The creek outlets on the 837
west side of SR 167 into a roadside ditch dominated 838
by reed canarygrass. It then turns westerly between 839
two businesses and flows through a managed, turf-840
lined biofiltration swale before entering a City 841
stormwater system under East Valley Road. The 842
remaining 4,000 linear feet (LF) run primarily in a pipe 843
to the confluence with Springbrook Creek. What little 844
open channel does exist has no native riparian canopy 845
and completely lacks in-stream structures. 846
Fish passage 847
Due to the extent of piped channel combined with 848
extensive commercial development, the west fork of 849
Panther Creek is likely a complete barrier to upstream 850
fish passage. 851
Additional upstream barriers to fish passage in the 852
Panther Creek system 853
Upstream of the Panther Creek wetland complex, 854
WSDOT performed field reconnaissance to determine 855
whether other fish passage barriers existed in higher 856
portions of the watershed and at selected Panther 857
Creek culverts. Areas of concern were based on a 858
1989 Watershed Company Report that identified 859
several locations of concern for fish habitat and 860
passage. The field reconnaissance, described in RW 861
Beck (2006), identified three likely upstream barriers to 862
fish passage: 863
• Talbot Road culvert 864
• Carr Road culvert 865
• An earthen dam upstream of Carr Road 866
13 Fish Habitat Memorandum. Prepared by Derek Koellmann, Anchor Environmental. 2006.
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EXISTING CONDITIONS
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 24
Panther Creek crosses under Talbot Road in a 120-foot-867
long, 36-inch-diameter culvert. The pipe inverts have 868
been scoured away for about 3 feet on both the upstream 869
and downstream ends. The pipe goes through a large 870
roadway embankment and is 27 feet below the road 871
surface. The drop from the culvert’s downstream outlet 872
to the stream is approximately 4.2 feet. This drop from 873
the culvert outlet to the stream acts as a barrier to 874
upstream fish passage as do the high velocities and low 875
flow depths in the pipe. 14 876
Panther Creek crosses under Carr Road in a 150-foot-877
long, 6-foot-diameter culvert. The overall gradient is 878
4.5 percent and the culvert goes through a road 879
embankment and is approximately 30 feet below Carr 880
Road. The culvert outlet has a drop of about 3 feet 881
into an irregular series of cascades that drop into the 882
stream channel. From the culvert through the 883
cascades, the creek drops 7 feet over a distance of 25 884
feet. This creates difficult conditions for upstream 885
passage for most life stages of fish. This outlet is 886
considered a barrier to upstream fish passage.14 887
Approximately 120 feet upstream of the Carr Road 888
culvert, Panther Creek flows over an 11-foot-high 889
earthen and concrete dam. The dam has a trapezoidal-890
shaped concrete spillway that is failing. The dam and 891
spillway are barriers to upstream fish passage.14 892
There are no other documented barriers to fish passage 893
between here and Panther Lake. The ravine upstream 894
of SE 192nd Street is in good condition with a forested 895
riparian canopy, instream logs, pools and spawning 896
gravel in some places. 15 897
Rolling Hills Creek 898
Physical conditions 899
Rolling Hills Creek flows from the Rolling Hills 900
subbasin located south of I-405 as shown in Exhibit 4. 901
Resident fish species likely to occur in the reaches of 902
Rolling Hills Creek and its unnamed tributary within the 903
project area include sculpin and three-spine 904
stickleback.16 905
Approximately 1,000 feet south of the project area, 906
Rolling Hills Creek flows through a series of culverts 907
14 Fish Passage at Selected Panther Creek Culverts. RW Beck. 2006.
15 Panther Creek Salmonid Fish Habitat Restoration. The Watershed Company. 1989.
16 Inland fishes of Washington. Wydosky and Whitney. 1979.
Concrete earthen dam fish barrier, 120 feet
upstream of Carr Road culvert
Talbot Road culvert fish barrier at
downstream end
Carr Road Culvert fish barrier at
downstream end
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
EXISTING CONDITIONS
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 25
under several commercial parking lots to where it 908
ultimately daylights on the north side of I-405 into an 909
open channel between the Renton Cinema 8 parking 910
lot and I-405. The creek then flows westerly under the 911
I-405/SR 167 interchange, outlets into an open 912
channel along the south side of the interchange, and 913
then into another culvert system beginning at SR 167 914
and continuing to its confluence with Springbrook 915
Creek. 916
Stream habitat in this reach is poor for every habitat 917
parameter observed except for canopy cover and pool 918
habitat, see Exhibit 5. 919
Fish passage 920
No anadromous fish species are reported to occur in 921
Rolling Hills Creek or its unnamed tributary.17 This is 922
likely due to two downstream fish passage barriers. 923
The Rolling Hills Creek culvert under the I-405/SR 167 924
interchange is a partial fish passage barrier. The SW 925
19th Street culvert system between SR 167 and 926
Springbrook Creek has significant length to be 927
considered a complete fish passage barrier.18 928
Thunder Hills Creek 929
Physical conditions 930
The headwaters of Thunder Hills Creek are located to 931
the southeast of I-405. Resident fish species likely to 932
occur in the upper reaches of Thunder Hills Creek 933
include cutthroat trout, sculpin, and three-spine 934
stickleback.17 935
Upstream of I-405, Thunder Hills Creek flows in an 936
incised channel to where it crosses under I-405 937
(Exhibit 4). After flowing under I-405, it daylights into a 938
concrete outfall located directly behind Sam’s Club. 939
After daylighting at the outfall, Thunder Hills Creek 940
combines with water flowing from a historic, now 941
abandoned coal mine. From the confluence of these 942
two flows, Thunder Hills Creek and the coal mine 943
runoff enter a three-sided concrete flume. The flume 944
flows along the southeast edge of Sam’s Club parking 945
lot and outlets into an open stream channel associated 946
with a wetland complex immediately east of Talbot 947
17 Distribution of Salmon and Trout Water Resource Inventory Area (WRIA) 8 Lake Washington/Cedar/Sammamish
Watershed. KCDNR. 2001.
18 Panther Creek Watershed Restoration Project Existing Conditions Synopsis. Anchor Environmental. February 28,
2006.
Thunder Hills Creek in concrete flume on
north side of I-405
What are Anadromous vs. Resident Fish?
Anadromous fish are born in freshwater
streams, rivers, or lakes, spend their adult
phase in the ocean, and return to their
original waters to spawn.
Resident fish spend their entire lives in
freshwater systems and do not migrate into
saltwater environments.
Rolling Hills Creek on north side of I-405
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EXISTING CONDITIONS
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 26
Road South and north of I-405. The creek then flows 948
west under Talbot Road and into a series of culverts 949
before it daylights and converges with Rolling Hills 950
Creek between the Renton Cinema 8 parking lot and 951
I-405. 952
Fish passage 953
Thunder Hills Creek shares the same barriers to fish 954
passage that are described for Rolling Hills Creek. 955
956
Exhibit 5. Stream Habitat Conditions Summary
Panther Creek East Fork
Habitat
Parameter
Springbrook
Creek
Downstream of
SR 167
Upstream of SR 167
(South wetland)
Panther
Creek West
Fork
Rolling Hills
Creek
Thunder
Hills Creek
DNR Stream
Type S F F F F F
Streambank
Stability Marginal Suboptimal Suboptimal Suboptimal Poor Optimal
Streambank
Vegetative
Protection
Marginal Poor Marginal Poor Poor Poor
Riparian Zone
Width Marginal Poor Poor Poor Poor Marginal
Substrate
Embeddedness Poor Poor1 Poor Poor Poor Suboptimal3
Canopy Cover Suboptimal Marginal Suboptimal Poor Marginal Suboptimal
LWD
Frequency Poor Poor1 Poor Poor Poor Marginal
Pool Quality Suboptimal Marginal N/A2 Marginal Suboptimal Marginal
Channel
Alteration Marginal Poor Marginal Poor Poor Poor
DEFINITIONS
Optimal streams have stable banks, good canopy cover, a wide riparian zone, large woody debris (LWD) and a normal channel pattern, etc.
Suboptimal streams have moderately stable banks, average canopy cover, riparian zone and LWD and a normal channel pattern, etc.
Marginal streams have moderately unstable stable banks, below average canopy cover, an impacted riparian zone, LWD and a disrupted channel pattern, etc.
Poor streams have unstable banks, little canopy cover, an absence of LWD and severe channel alteration (e.g., rip rap).
(For a full definition of these ratings, See Appendix B, Fish Habitat Memorandum, Anchor Environmental, 2006.)
1. Due to the nature of the stream channel within the Panther Creek Wetland Complex, certain habitat parameters, such as substrate embeddedness and LWD,
are not readily applicable to the nature of the stream system and may be properly functioning based on the natural interaction between Panther Creek and its
associated wetland in this area.
2. No pools were found in the study reach.
3. A large portion of Thunder Hills Creek is contained in a concrete flume, and as such, the majority of the streambed is composed of concrete.
S = shorelines of the state; F = not classified as Type S, but are natural waters that have fish, wildlife, or human use.
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EXISTING CONDITIONS
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 27
What is the current status of water quality in Panther and 957
Springbrook Creeks? 958
During 2001 and 2002 Springbrook Creek and 959
Panther Creek were sampled as part of the Green-960
Duwamish Watershed Water Quality Assessment. 961
Springbrook Creek was sampled in vicinity of its 962
mouth and downstream of I-405. Panther Creek East 963
Fork was sampled east of SR 167 in the Panther 964
Creek Wetland. The median base flow water quality 965
values for temperature, dissolved oxygen and 966
dissolved copper from this sampling are shown in 967
Exhibit 6. 968
Chronic water quality problems in the Springbrook 969
basin include exceptionally low concentrations of 970
Dissolved Oxygen (DO), high turbidity, high levels of 971
fecal coliform bacteria, Total Suspended Solids (TSS), 972
and ammonia.19 973
974
Exhibit 6. 2001 and 2002 Springbrook Creek and Panther Creek median
base flow water quality values 20
Water Quality Parameter
Location
Temperature
(degrees C)
Dissolved Oxygen
(mg/L) Dissolved Copper (mg/L)
Springbrook Creek 11.5 4.7 0.0011
Panther Creek 10.5 12.3 0.0012
975
State water standards for temperature define a 976
maximum 16.0° C in core salmonid rearing waters and 977
17.5° C in noncore salmonid rearing waters (as 978
determined on a seven-day average daily maximum). 979
State water standards require dissolved oxygen 980
concentrations exceed 9.5 mg/L in freshwaters 981
designated for core salmonid rearing and 8.0 mg/L in 982
freshwaters designated for noncore rearing. 983
Springbrook Creek is on the state’s 1998 303(d) list as 984
impaired for temperature, DO and copper. King 985
County21 identified high temperature and low DO 986
19 Kerwin. 2001.
20 King County and Herrera. 2004.
21 King County. 2000.
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
EXISTING CONDITIONS
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 28
concentrations as a probable cause for the decline of 987
salmonids in Springbrook Creek. 988
What is the current status of stream flow diversions in the watershed? 989
Streams affected by diversions 990
Stream flows within this watershed have been altered 991
by diversions (City of Renton 1997), an important point 992
when considering a watershed rehabilitation plan. 993
Rolling Hills Creek, east of SR 167, has a flow split 994
(diversion) that can direct water into the north Panther 995
Creek wetland during flood conditions. 996
Panther Creek Stream flows can be split at the alluvial 997
fan that has formed where Panther Creek flows onto 998
the valley floor. For example, in recent years, more 999
stream flow has been diverted into the west fork of 1000
Panther Creek (SW 34th Street system) and less into 1001
the east fork. More recently field observations 1002
confirmed that sedimentation in the alluvial fan has 1003
directed the majority of Panther Creek flows into the 1004
south Panther Creek wetland. A fish ladder was 1005
installed on the east fork of Panther Creek upstream 1006
of the SR 167 crossing. As part of this work, several 1007
SR 167 cross culverts were blocked in an effort to 1008
concentrate stream flow towards the fish ladder. 1009
Management of the stream flows at these locations is 1010
an important factor in development of the rehabilitation 1011
concept in the next chapter. 1012
What is the current status of wildlife in the watershed areas proposed 1013
by this concept plan? 1014
The wetlands and riparian corridors of the PCW have 1015
high quality habitat and support a higher abundance 1016
and diversity of wildlife compared to that provided by 1017
roadside and urban matrix habitats. The wetlands 1018
have several functions and values that are important 1019
to wildlife species such as providing shelter and 1020
foraging habitat for migratory and resident birds such 1021
as great blue heron, mallard duck, red-tailed hawk, 1022
and red-winged blackbird and small animals such as 1023
raccoons. 1024
Wildlife use of the wetlands is mainly limited to riparian 1025
bird species. Animals that rely on shallow marsh 1026
areas are restricted in number and variety, largely due 1027
to the lack of persistent, open water and low habitat 1028
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EXISTING CONDITIONS
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 29
diversity within the extensive stands of cattails and 1029
reed canarygrass.22 1030
Riparian corridors in this project area contain elements 1031
of both aquatic and terrestrial ecosystems. The riparian 1032
corridors typically support aquatic habitats and functions 1033
within the watercourse that they are associated. 1034
Streams and their associated riparian corridors 1035
frequently provide refuge and foraging opportunities and 1036
may provide an essential migratory route that links 1037
otherwise isolated wildlife populations.23 1038
No known terrestrial federally listed species or federal 1039
species of concern occur within the PCW as discussed 1040
in the Tukwila to Renton Improvement Project (I-5 to SR 1041
169 – Phase 2) Upland Vegetation and Wildlife 1042
Discipline Report. No bald eagles occur within the 1043
PCW. For additional information on regulated species 1044
please refer to the Tukwila to Renton Improvement 1045
Project (I-5 to SR 169 – Phase 2) Biological 1046
Assessment. 1047
1048
22 P-9/Panther Creek Project Wetlands Inventory. June 29, 1989. The Coot Company.
23 Renton Nickel Improvement Project Upland Vegetation And Wildlife Discipline Report. WSDOT. 2005.
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
EXISTING CONDITIONS
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 30
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
CONCEPT DEVELOPMENT
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 31
C ONCEPT D EVELOPMENT 1049
What are the I-405 improvements that this concept plan addresses? 1050
The PCWRP provides watershed-level stream 1051
mitigation for the effects to streams from the I-405, I-5 1052
to SR 169 Master Plan in the Panther Creek and lower 1053
Springbrook Creek watersheds. The I-405/SR 167 1054
interchange reconfiguration and SR 167 realignment 1055
were reviewed to understand the effects (see before 1056
and after figures, left). The proposed highway 1057
configuration minimizes these effects by using 1058
“stacked” freeway ramps within the interchange to 1059
reduce the roadway footprint. 1060
WSDOT is currently preparing the Environmental 1061
Assessment (EA) for the Tukwila to Renton 1062
Improvement Project (Tukwila to Renton EA). As a 1063
result of the Tukwila to Renton EA, I-405 Team 1064
engineers have estimated the effects to streams and 1065
wetlands from the Tukwila to Renton roadway 1066
footprint. Because the PCWRP is based on the 1067
Master Plan footprint (which does not have the same 1068
design detail as Tukwila to Renton), the I-405 Team 1069
needed to understand the difference between the 1070
Tukwila to Renton and Master Plan footprints. 1071
The main differences between footprints for the I-405 1072
Master Plan and Tukwila to Renton Project are the 1073
alignment of southbound (SB) SR 167 and the ramp 1074
connections between south and west segments of the 1075
interchange. 1076
In the Tukwila to Renton footprint, the SB SR 167 is 1077
reconstructed on a new alignment from about SW 27th 1078
Street to I-405. In the Master Plan, SB SR 167 is 1079
reconstructed on a new alignment from the SW 41st 1080
Street off-ramp to just north of SW 27th Street and 1081
high occupancy vehicle (HOV) direct access ramps to 1082
SW 27th Street are constructed. 1083
Additional improvements to the I-405/ SR 167 1084
interchange included in the Master Plan but not in the 1085
Tukwila to Renton footprint include HOV direct 1086
connector ramps between the south and west legs of 1087
the interchange (northbound (NB) SR 167 to SB I-405 1088
and NB I-405 to SB SR 167), general-purpose 1089
(GP) direct connector ramp from NB SR 167 to SB I-1090
405, and HOV direct access ramps between I-405 and 1091
Rainier Ave (SR 167). 1092
I-405 /SR 167 Interchange “Existing”
I-405 /SR 167 Interchange “Tukwila to
Renton Project”
I-405 /SR 167 Interchange “Master Plan”
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
CONCEPT DEVELOPMENT
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 32
The I-405 Master Plan will have a larger footprint than 1093
the Tukwila to Renton project in and around the SR 1094
167 and I-405/ SR 167 Interchange area because of 1095
these additional improvements. Along SR 167, the 1096
additional realigning of SB SR 167 increases the 1097
footprint along the west side of SR 167 from the 1098
SW 41st Street off-ramp to just north of SW 27th 1099
Street. The new GP ramp from NB SR 167 to SB I-1100
405 increases the footprint along the east side of SR 1101
167 from about SW 27th Street to the north. The 1102
majority of this ramp is anticipated to be constructed 1103
as “above ground structure” to minimize the impacts 1104
on the Panther Creek Wetlands. The footprint of the 1105
west segment (leg) of the interchange will not increase 1106
as the additional ramps are constructed in median 1107
areas of the Tukwila to Renton project. 1108
What are the stream and wetland effects? 1109
The Master Plan will permanently affect approximately 1110
64,731 square feet of stream channel (below ordinary 1111
high water mark (OHWM)), approximately 5.48 acres 1112
of wetland and require replacement of the fish ladder 1113
structure at SW 23rd Street. 1114
Exhibits 7 and 8 summarize the potential permanent 1115
stream and wetland effects from the Master Plan 1116
Footprint (Exhibit 10) in the Panther/Springbrook 1117
Creek watersheds. 1118
Exhibit 7. Potential Stream Effects From Master Plan Footprint
Permanent Effects1
Location of
Stream Effect DNR Type Below OHWM (SF) Stream Buffer (AC)
Rolling Hills Creek (09.SC-28) F 4,738 0.66
Unnamed Tributary to Rolling Hills Creek (09.RH-2.6) F 699 0.28
Thunder Hills Creek (09.RH-3.0) F 2,463 0.86
Unnamed Tributary to Thunder Hills Creek (Stream
Tributary) F 76 0.10
East Fork Panther Creek (09.SC-25.7) F 44,654 0.272
West Fork Panther Creek (09.SC-24.7) F 12,101 0.68
Total Effects 64,731 2.85
1. Permanent stream effects are approximate and based upon the Tukwila to Renton Ecosystems Discipline Report and potential Master
Plan effects for these locations.
2. To avoid double counting for impacts to stream and wetland buffers, additional effects to stream buffers are included in the Panther
Creek Wetland Buffer effects found in Exhibit 8.
SF = square feet; AC = Acres; DNR Stream type: F = not classified as shorelines of the state, but are natural waters that have fish, wildlife, or
human use
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
CONCEPT DEVELOPMENT
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 33
1119
Exhibit 8. Potential Wetland Effects From Master Plan Footprint
Permanent Effects1
Location of Wetland Effect Category2 Wetland (AC) Wetland Buffer (AC)
Panther Creek Wetland
(24.7R) II 4.87 4.32
Wetland East of SR 167
(25.0L) III 0.61 3.27
Total Effects 5.48 7.59
1. Permanent stream effects are approximate and based upon the Tukwila to Renton Ecosystems Discipline Report and potential
Master Plan effects for these locations.
2. Washington State Wetland Rating System for Western Washington – Revised (Hruby 2004 )
AC = acres
1120
What objectives are proposed to rehabilitate streams and fish habitat? 1121
The PCWRP proposes the following objectives for 1122
rehabilitating streams and fish habitat that address the 1123
watershed limiting factors and capitalize on site 1124
specific opportunities: 1125
• Remove/improve barriers to fish passage at 1126
three locations including the SW 23rd Street 1127
fish ladder, Talbot Road, and Carr Road to 1128
improve watershed connectivity. This will open 1129
up to 3 miles of fish habitat for resident and 1130
juvenile salmonid species between the SW 1131
23rd Street fish ladder and Panther Lake. 1132
• Provide salmonid refuge for juvenile Chinook 1133
and coho from Springbrook Creek to use the 1134
Panther Creek Wetlands for overwinter rearing 1135
in off-channel wetlands and Panther Creek. 1136
Juvenile coho will also utilize the same 1137
overwinter habitat for rearing and feeding. 1138
Adults that try to access and use upper 1139
Panther Creek for spawning would also 1140
benefit.24 1141
• Provide functioning riparian habitat with in-1142
channel habitat structure (LWD). Increase 1143
native plant diversity and remove and/or 1144
control invasive species. 1145
24 Panther Creek Fish Passage Memorandum. LaRiviere. 2006.
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CONCEPT DEVELOPMENT
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Panther Creek Watershed Rehabilitation Conceptual Plan 34
• Improve degraded water quality by steepening 1146
channel’s longitudinal gradient near the alluvial 1147
fan (topography permitting) to aerate flows for 1148
increased dissolved oxygen. Riparian shade 1149
plantings near channel to lower summer water 1150
temperatures. 1151
To achieve the above objectives, these actions will be 1152
implemented as shown in Exhibits 9 and 10: 1153
Stream Rehabilitation 1 (SR1) 1154
The PCWRP proposes several off-site and out-of-kind 1155
mitigation opportunities for effects to Rolling and 1156
Thunder Hills Creeks. This is consistent with the 1157
watershed level approach and based on the following 1158
three factors: 1159
• The affected stream reaches in Rolling and 1160
Thunder Hills Creeks have poor, fragmented 1161
habitat. 1162
• Rolling Hills Creek is piped for more than 2,000 1163
LF between SR 167 and Springbrook Creek 1164
(SW 19th Street). 1165
• Prioritization of Master Plan mitigation dollars 1166
to address watershed limiting factors. 1167
I-405 road widening will affect Rolling Hills Creek and 1168
Thunder Hills Creek. Rolling Hills Creek will be 1169
affected in the vicinity of the SR 515 and SR 167 1170
Interchanges in the locations described in Exhibit 7. 1171
The affected reaches will be piped as a result of ROW 1172
limitations and fills and retaining walls necessary for 1173
road widening (Exhibit 9). WSDOT proposes off-site 1174
and out-of-kind mitigation for these effects with stream 1175
rehabilitation on Lower Springbrook Creek. This 1176
location has been identified by the City of Renton, 1177
U.S. Army Corps of Engineers (Corps) and the King 1178
County 2005 Green/Duwamish and Central Puget 1179
Sound Watershed Salmon Habitat Plan.25 1180
1181
25 Green/Duwamish and Central Puget Sound Watershed Salmon Habitat Plan. Washington State Department of Fish
and Wildlife. August 2005.
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW CONCEPT DEVELOPMENT I-405 Water Resource Initiative at Panther Creek Wetlands Panther Creek Watershed Rehabilitation Conceptual Plan 35 SpringbrookCreekEast ForkPanther CreekPanther CreekSW 23rd StTalbot Road SouthTalbot Road SouthSpringbrook CreekBlack River Pump StationFish Passage ModificationsGreen RiverRENTONRolling Hill CreekThunderHills CreekPantherLakeSR3FI2SR4Springbrook CreekWetland and HabitatMitigation BankRenton Nickel Stream Mitigationon Springbrook CreekSW 41st StFI1SR2SE Carr RdWest ForkPanther CreekPantherSR5167181Thunder Hills CreekEast ForkCreekTSR1S W 1 2 t h S t
S W G r a d y W a yLind Ave SWEast Valley RdSW 27th StSW 34th StSW 16th StSW 19th StSW 39th StRaymond Ave SWSW 29th StSW 21st StMaple Ave SWENLARGEMENT PLAN (EXHIBIT 10)0500FeetLegendOther Watershed RehabilitationEfforts Not Part of This PlanMaster Plan FootprintEnhance 25 acres of stream buffer/PEM wetlandsdominated by reed canarygrass and create off-channelwetland fish habitat.Enhance 7.5 acres of stream buffer/PF01 wetland.Plant native understory and conifers. Control/removereed canarygrass.Rehabilitate 2,400 LF of lower Springbrook Creekstream bank (approved by WRIA9).Construct Springbrook Trail (2,400 LF).Replace SW 23rd Street fish ladder to improve fishpassage.Relocate 5,350 LF of Panther Creek and provideoff-channel wetland fish habitat. Deepen channelcross section.Replace Talbot Road South culvert to eliminate fishpassage barrier.Carr Road culvert modifications and earthen/concretedam removal to eliminate barriers to fish passage.SR2SR3SR4SR5FI1FI2SR1TStream RehabilitationAssociated Floodplain ImprovementsStream (Open Channel)Stream (Piped)Stream Relocation for SR 167 HOV LaneProposed Trail 1182 Exhibit 9. Concept Plan 1183
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW CONCEPT DEVELOPMENT I-405 Water Resource Initiative at Panther Creek Wetlands Panther Creek Watershed Rehabilitation Conceptual Plan 36 1184 1185
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW CONCEPT DEVELOPMENT I-405 Water Resource Initiative at Panther Creek Wetlands Panther Creek Watershed Rehabilitation Conceptual Plan 37 Talbot Road SouthTalbot Road SouthSW 41st St FI1 SW 23rd StPanther CreekSpringbrook CreekEast Fork Panther CreekWest Fork Panther CreekEast ForkSpringbrook CreekAAAASpringbook CreekWetland and HabitatMitigation Bank167SR5Rolling Hill CreekRolling Hill CreekPermanentDiversionPanther CreekTSR1S W 1 2 t h S t S W G r a d y W a yLind Ave SWEast Valley RdSW 27th StSW 34th StSW 16th StSW 19th StRaymond Ave SWSW 29th StS W 1 3 t h S tSW 21st StMaple Ave SWSR3 FI1 FI2 SR4SR2Legend0250FeetExisting Contour (2 FT contour interval)Stream (Piped)Master Plan FootprintOther Watershed RehabilitationEfforts Not Part of This PlanDirect Discharge Areasfrom Master Plan FootprintAssociated Floodplain ImprovementsStream RehabilitationStream Relocation for SR 167 HOV LaneEnhance 25 acres of stream buffer/PEM wetlandsdominated by reed canarygrass and create off-channelwetland fish habitat.Enhance 7.5 acres of stream buffer/PF01 wetland.Plant native understory and conifers. Control/removereed canarygrass.Rehabilitate 2,400 LF of lower Springbrook Creekstream bank (approved by WRIA9).Construct Springbrook Trail (2,400 LF).Replace SW 23rd Street fish ladder to improve fishpassage.Relocate 5,350 LF of Panther Creek and provideoff-channel wetland fish habitat. Deepen channelcross section.Replace Talbot Road South culvert to eliminate fishpassage barrier.Carr Road culvert modifications and earthen/concretedam removal to eliminate barriers to fish passage.SR2SR3SR4SR5TFI1FI2SR1Proposed TrailProposed StreamStream (Open Channel) 1186 Exhibit 10. Concept Plan Enlargement 1187
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW CONCEPT DEVELOPMENT I-405 Water Resource Initiative at Panther Creek Wetlands Panther Creek Watershed Rehabilitation Conceptual Plan 38 1188 1189
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
CONCEPT DEVELOPMENT
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 39
The Corps Green/Duwamish River Basin Ecosystem 1190
Restoration Study (Site No. 7) proposed conceptual 1191
design (Appendix C) for channel and habitat 1192
modifications in the area identified in the City of 1193
Renton’s 1997 East Side Green River Watershed 1194
Project (ESGRWP). WSDOT proposes to use 1195
implement a 2,400 LF reach of Site No. 7 as an 1196
alternative watershed project to mitigate effects to the 1197
Rolling Hills and Thunder Hills creeks (See SR1, 1198
Exhibit 9). The goal of the Corps plan for the Lower 1199
Springbrook Creek reach is to create a natural habitat 1200
for rearing and storm refuge that increases the 1201
hydraulic capacity of the channel. 1202
Limiting factors identified in the ESGRWP indicate that 1203
the reach is lacking native riparian vegetation and 1204
reed canarygrass and black berries leave the stream 1205
surface open to solar insulation. There is essentially 1206
no instream habitat such as woody debris. 1207
In response, habitat improvements would include 1208
plantings in the riparian corridor and placement of 1209
large woody debris in the creek. The Corps identified 1210
locations for one stage and two stage channels (see 1211
typical cross sections Appendix C). The proposed 1212
channel would have a higher cross sectional area than 1213
that of the existing channel to prevent a decrease in 1214
hydraulic capacity.28 This plan proposes to implement 1215
a portion, 2,400 LF (70,000 SF below OHWM) of the 1216
Corps plan downstream of SW 23rd Street. Stream 1217
rehabilitation will include the following (Appendix C): 1218
• Place LWD (2 pieces every 50 feet) and 1219
plantings in a re-channeled reach with minimal 1220
disturbance of the low flow channel. 1221
• Create in-channel pools. Excavating moderate 1222
pools for placement of wood will prevent it from 1223
decreasing the hydraulic capacity of the 1224
channel. 1225
• Excavate channel branch dendrites. 1226
• Create a 1-stage and 2-stage (low- and high-1227
flow) channel (where appropriate). 1228
• Create hummocks (every quarter mile) with cut 1229
material from dendrite construction and re-1230
channeling will limit off-site haul and promote 1231
geochemical functions. 1232
28 U.S. Army Corps of Engineers. 2000.
Lower Springbrook Creek at Creek Mile 1.0,
Project LG-19 in the WRIA 9 Salmon
Habitat Plan
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
CONCEPT DEVELOPMENT
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 40
This work will require environmental easements through 1233
various private properties. Any instream habitat 1234
improvements will require the permission of the King 1235
County drainage district No. 1, which owns a 40-foot 1236
width of ROW along the creek. 1237
Stream Rehabilitation 2 (SR2) 1238
The fish ladder at SW 23rd Street will be relocated 1239
due to the Master Plan footprint east of SR 167. This 1240
plan proposes replacement of the fish ladder with a 1241
structure that meets the 2003 WDFW guidelines for 1242
freeboard, fishway bends, and depth over the weirs for 1243
a fish passage target flow of 34 cfs (Appendix B). 1244
Stream Rehabilitation 3 (SR3) 1245
Approximately 44,654 SF (East Fork) and 12,101 SF 1246
(West Fork) of Panther Creek will be affected by fills 1247
and retaining walls necessary for road widening 1248
(Exhibit 10). To mitigate for these effects, this plan 1249
proposes to rehabilitate approximately 5,350 LF 1250
(85,000 SF below OHWM) of East Fork Panther Creek 1251
located in the PCW. Stream rehabilitation will include 1252
the following: 1253
• Relocate Panther Creek out of the confined 1254
roadside ditch and restore a riparian 1255
buffer/wetland/stream complex that provides 1256
the 115-foot stream buffer required by 1257
Washington State Department of Natural 1258
Resources (DNR) for a Type F stream. This 1259
single action will restore 12.81 AC of riparian 1260
buffer between SR 167 and the west bank of 1261
Panther Creek to improve water quality and 1262
riparian habitat. 1263
• Create a natural meandering channel 1264
morphology that is hydraulically connected with 1265
the riverine wetland. 1266
• Create a deeper channel cross section (+/-3 1267
feet below existing grade, channel width to be 1268
determined) to provide for fish passage as 1269
base flow. Steepen the channel’s longitudinal 1270
gradient near the alluvial fan (topography 1271
permitting) to aerate flows, increase dissolved 1272
oxygen and improve water quality. 1273
• Match the new stream longitudinal profile to 1274
critical existing elevations. The downstream 1275
end will meet and match the existing fish 1276
Panther Creek east fork at alluvial fan
exhibits extensive braiding and
sedimentation during storm events
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
CONCEPT DEVELOPMENT
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 41
ladder invert elevation to maintain current 1277
groundwater levels in wetland and bed control. 1278
• Allow for sediment trapping within alluvial fan 1279
area. 1280
• Provide a permanent diversion of Panther 1281
Creek flows to the south Panther Creek 1282
Wetland. This will provide a more reliable 1283
water source to the east fork stream channel in 1284
the south wetland to avoid periodic flow shifts 1285
and resulting impacts to stream and wetland 1286
hydrology that have occurred in the past. 1287
Avoid the 18-inch King County sewer line. 1288
• Connect new channel with the “SR 167 HOV 1289
Lane Project” (where feasible) (Exhibit 10). 1290
This would occur downstream of the flow split 1291
due to elevation constraints. 1292
• Excavate degraded palustrine emergent (PEM) 1293
+/-2 feet to flood out reed canarygrass and 1294
provide off-channel wetland juvenile fish 1295
rearing habitat in key locations (Exhibit 12). 1296
Fluvial geomorphology, wetland hydrology, 1297
sedimentation, and geotechnical analysis are key 1298
design processes that WSDOT will evaluate to 1299
relocate the stream to the middle of the Panther Creek 1300
wetland. Wetland hydrology is likely dependent upon 1301
a combination of groundwater, overbank flood flows 1302
from Panther Creek and seeps/drainages from Talbot 1303
Hill. Changes to the wetland hydroperiod associated 1304
with stream channel excavation and permanent 1305
diversion will likely help to stabilize south wetland 1306
hydroperiod. 1307
Sediment deposition is occurring at an accelerated 1308
rate in the alluvial fan. Stabilization of eroding 1309
streambanks upstream of the wetland and on-site 1310
maintenance (sediment traps) would likely address 1311
this problem. 1312
Construction of a channel in the south wetland will be 1313
challenging due to the high groundwater table and 1314
dense layer of reed canarygrass (generally +/-12 1315
inches deep). Channel construction will be feasible if: 1316
• Work is done in the dry season and within the 1317
appropriate in-water work windows. 1318
• Low-ground-pressure tracked equipment is 1319
used in conjunction with steel plates or lie 1320
Panther Creek west fork at inlet to SR 167
culvert looking northward
What is a hydroperiod?
A hydroperiod refers to the period of time a
wetland is covered with water. Changes to
how long a hydroperiod lasts can alter the
types of plants and animals that a wetland
supports.
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
CONCEPT DEVELOPMENT
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 42
down mats, and/or a temporary hog-fuel type 1321
road for construction access into the wetland.29 1322
WSDOT will evaluate these design elements further 1323
as funding becomes available. Evaluation will include 1324
collection of groundwater data using wells and borings 1325
from geotechnical exploration that will further refine 1326
this plan. 1327
Stream Rehabilitation 4 (SR4) 1328
The Panther Creek/Talbot Road 120-foot-long, 3-foot-1329
diameter culvert is a complete barrier to fish passage 1330
due to the outlet drop (+/-4 feet) combined with high 1331
velocities and low flow depths in the pipe30 (Appendix 1332
B). This fish barrier eliminates fish connectivity to the 1333
upper reaches of the watershed. The PCWRP 1334
proposes the following fish passage improvements to 1335
the Panther Creek/Talbot Road culvert (Exhibit 9) as 1336
off-site, out-of-kind mitigation for effects to Rolling Hills 1337
and Thunder Hills Creeks: 1338
• Replace the culvert with a 5-foot-high by 18-1339
foot-wide stream simulation box culvert. 1340
• Install several upstream and downstream weirs 1341
to create a suitable gradient through the culvert 1342
for fish passage. 1343
Stream Rehabilitation 5 (SR5) 1344
The Panther Creek/SE Carr Road culvert is a barrier 1345
to upstream fish passage due to a 3-foot drop at the 1346
outlet and a series of irregular drops and cascades at 1347
the downstream end.31 The PCWRP proposes the 1348
following fish passage improvements to the Panther 1349
Creek/Carr Road culvert (Exhibit 9) as off-site, out of 1350
kind mitigation for effects to Rolling Hills and Thunder 1351
Hills Creeks: 1352
• Install a series of weirs at the culvert outlet to 1353
step the channel up to the culvert. 1354
• Replace 30 feet of culvert at downstream end. 1355
• Retrofit existing portion of culvert with baffles. 1356
• Remove earthen and concrete dam 120 feet 1357
upstream of Carr Road culvert. This would 1358
29 WSDOT Panther Creek Wetlands Assessment. Jones & Stokes. October 19, 2005.
30 Fish Passage at Selected Panther Creek Culverts. RW Beck. February 24, 2006.
31 Fish Passage at Selected Panther Creek Culverts. RW Beck. February 24, 2006.
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
CONCEPT DEVELOPMENT
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 43
include reconstruction of 250 feet of natural 1359
channel at a gradient of about 6.5 percent and 1360
a step-pool channel configuration (Appendix B) 1361
to provide upstream fish passage. 1362
Stream rehabilitation summary 1363
As shown in Exhibit 11, the PCWRP provides 162,000 1364
SF (below OHWM) of stream rehabilitation. 1365
1366
Exhibit 11. Summary of Proposed Stream Rehabilitation
Location DNR Type
Below OHWM
(LF)
Below OHWM
(SF)
Fish Barrier
Removal (LF)
Stream Buffer
(AC)
SR1 (Springbrook
Creek) S 2,400 70,000 4.40
SR2 (SW 23rd St. Fish
Ladder) F 800 75
SR3 (Panther Creek) F 5,350 85,000 **
SR4 (Panther Cr./Talbot
Rd. Culvert) S 1,200 120
SR5 (Panther Cr. Carr
Rd. Culvert) F 5,000 425
Total Rehabilitation 7,750 LF 162,000 SF 620 LF 4.40 AC
Total Effects
--
64,731 SF -- 2.85 AC
** Panther Creek stream buffer enhancements are shown in associated floodplain improvements, Exhibit 13.
OHWM = ordinary high water mark; LF = linear feet; AC = acres; SF = square feet
DNR Stream types: S = shorelines of the state; F = not classified as Type S, but are natural waters that have fish, wildlife, or human use
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
CONCEPT DEVELOPMENT
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 44
What objectives are proposed for associated floodplain 1367
improvements? 1368
North Wetland 1369
The North Wetland is characterized by a high quality 1370
palustrine forested and palustrine scrub-shrub 1371
(PFO1/PSS1). WSDOT decided to not propose 1372
stream rehabilitation in this high quality wetland. In 1373
this area, the downstream fish barriers posed by the 1374
SW 19th Street pipe made off-site stream 1375
rehabilitation options elsewhere in the watershed a 1376
priority. 1377
South Wetland 1378
The south wetland is a combination of high quality PSS1 1379
(to the north) and PFO1 (to the south) wetland vegetation 1380
communities that are separated by a large PEM 1381
community (Exhibit 3). The greatest opportunity for 1382
wetland enhancement in the PCW is in the south wetland 1383
because of invasive species (e.g., cattails and reed 1384
canarygrass) that predominate. 1385
The PCWRP proposes the following objectives for the 1386
Panther Creek South Wetland: 1387
• Increase native plant diversity. 1388
• Improve general habitat function. 1389
To achieve these objectives, the following actions will 1390
be implemented in locations shown in Exhibit 10: 1391
Floodplain Improvement Area 1 (FI1) 1392
Enhance +/-25 AC of floodplain that is PEM wetland 1393
and/or stream buffer as follows: 1394
• Excavate (2 to 3 feet) to establish semi-1395
permanently ponded deep PEM areas (where 1396
appropriate) for off-channel wetland fish habitat 1397
and to flood out reed canarygrass. Exhibit 12 1398
shows a typical cross section (A-A) through the 1399
south wetland. 1400
• Improve wetland microtopographic complexity 1401
by mounding (+/-18 inches) along fringe PEM 1402
areas dominated by invasive species (e.g., 1403
cattail and/or reed canarygrass) and planting 1404
with PFO/PSS vegetation (e.g., live willow 1405
stakes) for stream shading. 1406
1407
WP1 is north of the gas pipeline corridor
WP2 is part of a palustrine scrub-shrub
wetland (PSS1) with willow thickets
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW CONCEPT DEVELOPMENT I-405 Water Resource Initiative at Panther Creek Wetlands Panther Creek Watershed Rehabilitation Conceptual Plan 45 1408 Exhibit 12. Typical Panther Creek Wetland Cross Section A-A 1409
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
CONCEPT DEVELOPMENT
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 46
• Install wetland habitat structures (e.g., snags, 1410
windthrow mounds, down logs, etc.). 1411
Floodplain Improvement Area 2 (FI2) 1412
• Enhance +/-7.5 AC of PFO1 wetland 1413
community (Exhibit 10). 1414
• Remove and/or control invasive species in 1415
understory (e.g., Himalayan blackberry and 1416
reed canarygrass). 1417
• Infill mature PFO1 wetland with native 1418
understory and evergreen tree plantings. 1419
Floodplain Improvements summary 1420
As shown in Exhibit 13, the PCWRP provides 32.5 1421
acres of floodplain improvements associated with 1422
stream rehabilitation in the south wetland. 1423
1424
Exhibit 13. Summary of Associated Floodplain
Improvements
Location
Ecology
Category1
Wetland Enhancement and/or Stream
Buffer Enhancement (AC)
FI1 II 25.0
FI2 II 7.5
Proposed Floodplain Improvement 32.5 AC
Total Permanent Wetland Effects 5.48
Total Wetland Buffer Effects 7.59
1. Washington State Wetland Rating System for Western Washington – Revised (Hruby 2004 )
AC = acres
1425
Please note that floodplain improvements are 1426
necessary to provide for successful and self-1427
sustaining stream rehabilitation in the PCW. 1428
PCWRP will not seek wetland mitigation for 1429
highway improvements with this plan because 1430
WSDOT intends to provide wetland mitigation in 1431
this portion of the I-405 Corridor by debiting credits 1432
from the Springbrook Creek Wetland and Habitat 1433
Mitigation Bank. 1434
1435
What is the Springbrook Creek Wetland
and Habitat Mitigation Bank?
The Springbrook Creek Wetland and Habitat
Mitigation Bank are being developed as a
joint effort between WSDOT and the City of
Renton. This ‘bank’ will construct a new high
quality wetland complex that will serve to
replace other wetlands that are filled in by
projects such as the Renton Nickel
Improvement Project. In addition to wetland
mitigation, the site will also provide flood
storage mitigation.
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
CONCEPT DEVELOPMENT
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 47
What objectives are proposed for surface water? 1436
The PCWRP has several objectives for surface water 1437
management including: 1438
• Improve fish habitat, including stream flows; 1439
• Improve and/or preserve wetland functions and 1440
values; 1441
• Reduce flooding downstream of the Panther 1442
Creek wetland complex; 1443
• Improve water quality; 1444
• Provide cost-effective freeway stormwater 1445
management that is compatible with the 1446
wetland and stream habitat. 1447
Strategy for stream flow management 1448
Each of the above objectives for surface water is 1449
discussed as they relate to a recommended strategy 1450
for stream flow management. Appendix C provides a 1451
summary of the hydraulic analyses and the technical 1452
memoranda that serve as the basis for this discussion. 1453
The strategy for stream flow management makes the 1454
following assumptions: 1455
Panther Creek flows will be permanently 1456
diverted into the south Panther Creek wetland 1457
to provide adequate stream flow for fish 1458
habitat. 1459
The above diversion will minimize flows out of 1460
SW 34th Street culvert and reduce 1461
downstream flooding. 1462
More flow will be sent to the SW 19th Street 1463
drainage system, rather than the north Panther 1464
Creek wetland, while still meeting downstream 1465
flood control needs on the 19th Street system 1466
and Springbrook Creek. 1467
The 23rd Street outlet from the Panther Creek 1468
wetland will be slightly constricted when the 1469
fish ladder is replaced to compensate for the 1470
permanent diversion of Panther Creek into the 1471
south wetland and reduce downstream 1472
flooding. 1473
The Renton Village storm system is already 1474
improved per City’s plans to eliminate existing 1475
flooding. 1476
The Master Plan Roadway footprint will be 1477
built. 1478
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
CONCEPT DEVELOPMENT
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 48
A portion of the highway drainage will be 1479
directly discharged to Panther Creek wetland. 1480
Improve stream flows for fish habitat 1481
A characterization of the flows (nhc)30 for Panther 1482
Creek suggests that stream flows are limiting fish 1483
habitat when these flows are diverted to the SW 34th 1484
Street culvert by sedimentation in the alluvial fan. 1485
Exhibit 14 shows stream flows when the alluvial fan 1486
diverts flows to the SW 34th Street culvert. Also 1487
shown are stream flow predictions when stream flows 1488
are permanently diverted into the south Panther Creek 1489
wetland. 1490
1491
Exhibit 14. Predicted Average Monthly Panther Creek Stream Flows Entering
the South Panther Creek Wetland for Current Conditions31 Compared to the
Recommended Flow Management Strategy
Flow statistic September November January April July
Existing Land Use and Most Panther Creek flows diverted into the south outlet along 34th street
Average flow 0.01 0.22 0.27 0.06 0.00
Low flow (10%) 0.00 0.00 0.00 0.00 0.00
Existing Land Use and Panther Creek flows are permanently diverted into the south Panther Creek wetland
Average flow 0.67 3.88 5.05 1.80 0.42
Low flow (10%) 0.24 1.40 2.02 0.74 0.25
1492
From the information provided in Exhibit 14, we have 1493
concluded that a permanent diversion would be an 1494
important part of a preferred flow management 1495
strategy to improve fish habitat in the south Panther 1496
Creek wetland. 1497
Improve and/or Preserve Wetland Functions 1498
The PCW east of SR 167 is characterized by two 1499
distinct areas: a north forested wetland community and 1500
a south emergent wetland community that includes a 1501
mix of cattails and reed canarygrass. These areas are 1502
separated by a constructed berm (an Olympic gas 1503
pipeline corridor) near SW 23rd Street. Considering the 1504
higher quality forested wetland in the north, the strategy 1505
30 Appendix C – Fish Passage Evaluation at Central Panther Creek Outlet. nhc. February 2006.
31 Assumes the alluvial fan in the Panther Creek wetland is diverting flows to the SW 34th Street culverts.
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
CONCEPT DEVELOPMENT
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 49
for stream flow management is to send more flow to the 1506
SW 19th Street drainage system while meeting 1507
downstream flood control objectives. As a result, this 1508
would reduce stream discharge into the north forested 1509
wetland community. 1510
The south Panther Creek wetland would receive more 1511
flow as a result of the stream flow strategy. The effects 1512
of this strategy on wetland hydrology were evaluated for 1513
changes in wetland water surface elevations and 1514
durations. 1515
A comparison of the stream flow strategy to baseline 1516
conditions for flows and wetland water surface 1517
elevations is provided in Exhibit 15. 1518
During high flood flows, the Panther Creek wetland 1519
water surface elevations vary from 0.2-foot to 0.8-foot 1520
increase, depending on which flood recurrence 1521
interval is considered (see Appendix C – page 5 and 1522
Table 6 in nhc December 2006). For lower, more 1523
frequent stream flows, the difference in wetland water 1524
surface elevations are less that 0.2 feet (see Table 7 1525
in nhc December 2006). 1526
The increase in wetland water surface elevations as a 1527
result of high flows will not occur for an extended 1528
period of time and the seasonal changes in wetland 1529
elevations are minimal (see page 5 and Table 27 in 1530
nhc December 2006). 1531
1532
Exhibit 15. Predicted Surface Water Elevations in the Panther
Creek Wetland for Different Flood Flows for Baseline (Existing)
Conditions versus the Recommended Flow Management Strategy
Panther Creek Water Surface Elevations
2 year flow 10 year flow 50 year flow 100 year flow Existing Conditions 16.6 17.5 18.3 18.6
Panther Creek Water Surface Elevations
2 year flow 10 year flow 50 year flow 100 year flow
16.8 18.0 19.0 19.4
Difference
Recommended Strategy 0.2 0.5 0.7 0.8
Based on full build-out land use conditions – Data from Appendix C - nhc – December 2006 – Table 6 .
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
CONCEPT DEVELOPMENT
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 50
1533
Reduce flooding downstream of the Panther Creek 1534
wetland complex 1535
Specific locations were selected to evaluate the 1536
effects on flooding from the recommended flow 1537
management strategy. Some of the key areas 1538
included: 1539
SW 23rd Street Channel 1540
SW 19th Street Channel 1541
SW 34th Street Drainage System 1542
Springbrook Creek, downstream of confluence 1543
with SW 19th Street Channel 1544
For the SW 23rd Street Channel, a comparison of 1545
peak flows for the baseline (existing conditions) to the 1546
recommended flow management strategy (future 1547
condition) shows an increase in peak flows for more 1548
frequent floods (1/2 of the 2-year and 2-year) and a 1549
decrease in peak flows for less frequent floods (10-1550
year, 50-year, and 100-year). This means 1551
implementation of the recommended flow 1552
management strategy would reduce peak flows and 1553
could help reduce backwater conditions in the 23rd 1554
Street channel which exacerbate flooding in the East 1555
Valley Road system (see Appendix C – pages 5 and 6 1556
in nhc December 2006). 1557
For the SW 34th Street drainage system, flooding is 1558
an existing problem (City of Renton 1997). During 1559
high flood conditions, Springbrook Creek actually 1560
backs water up into the SW 34th Street drainage 1561
system to cause flooding. Panther Creek flood flows, 1562
crossing SR 167 at the SW 34th Street culverts 1563
exacerbate this flood condition along East Valley 1564
Road. Implementation of the recommended flow 1565
management strategy would reduce higher flood flows 1566
(10-year, 50-year, and 100-year) at the south Panther 1567
Creek wetland outlet about 4-fold (see Appendix C – 1568
Table 6 in nhc December 2006). 1569
For Springbrook Creek downstream of the confluence 1570
with the SW 19th Street channel, the flow 1571
management strategy does not increase the peak 1572
flows (50-year and 100-year), even with the increase 1573
in flows down the SW 19th channel (see Appendix C – 1574
page 6 and Table 6 in nhc December 2006). 1575
Prior modeling (Appendix C) revealed flow increases 1576
attributed to coincident peak flows form the SW 19th 1577
Street system with peaks in Springbrook Creek. 1578
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
CONCEPT DEVELOPMENT
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 51
Under the recommended alternative, the slight 1579
constriction of the 23rd Street outlet from the Panther 1580
Creek wetland results in eliminating flow increases in 1581
Springbrook Creek (see Appendix C – page 6 and 1582
Table 6 in nhc December 2006). 1583
Effects on Water Quality 1584
Dissolved oxygen concentrations in Springbrook 1585
Creek are limiting to aquatic life. An opportunity exists 1586
to improve dissolved oxygen concentrations in 1587
Panther Creek as it flows through the south wetland at 1588
the location of the existing alluvial fan. This channel 1589
area will need to be modified to provide the permanent 1590
diversion of Panther Creek as part of the stream flow 1591
management strategy. WSDOT acknowledges the 1592
dynamic nature of the geomorphic conditions of the 1593
Panther Creek alluvial fan. This analysis indicates 1594
that any plan to provide habitat enhancements within 1595
in the south end of the Panther Creek wetland should 1596
incorporate improvements to ensure that Panther 1597
Creek continues to flow to this location. During 1598
channel design, providing fish passage to upstream 1599
areas will be a key objective. In addition, an effort will 1600
be made in channel design to create cascades to 1601
promote water aeration. 1602
The highway stormwater runoff from SR 167 and the 1603
I-405 interchange area will be treated with enhanced 1604
treatment prior to discharge to the Panther Creek 1605
wetland. The water quality of this discharge will be an 1606
improvement over existing conditions due to the 1607
improved treatment technology. 1608
Effects of a partial direct discharge of treated highway 1609
stormwater on wetland hydrology? 1610
WSDOT evaluated the engineering feasibility, wetland 1611
effects, and project cost savings of a direct discharge 1612
of treated highway stormwater to the south Panther 1613
Creek wetland. I-405 team drainage engineers 1614
estimated that an area of about 28 acres of highway 1615
impervious surface could be routed and discharged, 1616
without detention, to the south Panther Creek wetland 1617
(see Exhibit 10). As noted above, this highway 1618
drainage discharge would receive enhanced water 1619
quality treatment but would not have flow control 1620
(detention). Nhc evaluated the effects of this 1621
discharge on the wetland hydrology of the Panther 1622
Creek wetland (nhc December 2006). Results 1623
showed that wetland hydrology in the Panther Creek 1624
wetland would not be impacted by the direct discharge 1625
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
CONCEPT DEVELOPMENT
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 52
of this stormwater. Wetland water surface elevations 1626
would not be measurably affected by the direct 1627
discharge (see page 5, nhc, December 2006). 1628
The benefits of providing the directed discharge of 1629
treated stormwater include: 1) compliance with airport 1630
safety guidance, and 2) lower drainage costs. As 1631
previously mentioned, the Federal Aviation 1632
Administration has guidelines that restrict open water 1633
areas within a 10,000-foot boundary of the Renton 1634
Municipal Airfield because of safety concerning aircraft 1635
encountering birds. Open detention ponds within this 1636
area can be eliminated as a result of creating a direct 1637
discharge to the south Panther Creek wetland. 1638
How does this plan fit into the context of other watershed projects? 1639
Several other projects are planned that will contribute 1640
to overall watershed rehabilitation efforts (Exhibit 10), 1641
although not included in the PCWRP. Some of these 1642
are described below. 1643
Springbrook Creek Wetland and Habitat Mitigation 1644
Bank 1645
The Springbrook Creek Wetland and Habitat 1646
Mitigation Bank are being developed as a joint effort 1647
between WSDOT and the City of Renton. This 1648
mitigation bank is constructing a new high quality 1649
wetland complex that will replace other wetlands that 1650
are impacted by projects such as the I-405: I-5 to SR 1651
169 Widening Project. In addition to wetland 1652
mitigation, the site will also provide flood storage 1653
mitigation. The Springbrook Creek Wetland and 1654
Habitat Mitigation Bank is one of the first urban 1655
mitigation banks to be certified in Washington State. 1656
WSDOT West Fork Panther Creek Stream Mitigation 1657
for SR 167 HOV 1658
Upstream of SR 167 on the west fork of Panther 1659
Creek, 775 feet of stream channel will be relocated in 1660
association with the SR 167 HOV Lane Widening 1661
Project. The stream channel centerline will be 1662
relocated approximately 25 feet to the west of SR 167. 1663
The concept plan acknowledges this project and our 1664
plan’s stream flow management strategy is to 1665
permanently divert Panther Creek flows to the south 1666
wetland. This would still leave the southern west 1667
branch tributary draining to the SW 34th Street culvert. 1668
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
CONCEPT DEVELOPMENT
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 53
Renton Nickel Stream Mitigation on Springbrook Creek 1669
Also, the Springbrook Creek box culvert under I-405 1670
will be removed and the streambed restored in that 1671
area as part of the construction of the new I-405 1672
bridge that will span both Springbrook Creek and 1673
Oakesdale Avenue. These new bridge(s) are being 1674
constructed as part of the I-5 to SR 169 Widening 1675
(formerly the I-405 Renton Nickel Improvement 1676
Project). The new bridge(s) will replace the existing 1677
I-405 bridge over the Springbrook Creek side channel 1678
and Oakesdale Avenue. 1679
Upgrade Black River Pump Station (BRPS) 1680
WRIA 9 Salmon Habitat Plan identifies the BRPS for 1681
modification to improve fish passage. The existing 1682
fish passage system at the BRPS does not meet 1683
current national (NMFS) or state (WDFW) fish 1684
passage criteria. Harza (1995) recommended minor 1685
improvements to fish passage. More recently, HDR 1686
(2006) recommended major improvements, including 1687
construction of new pool and chute fish ladders, ladder 1688
height and fish screen adjustments and reduction or 1689
elimination of pipe transport to update the existing fish 1690
passage infrastructure to current design codes for 1691
juvenile upstream migration and adult downstream 1692
migration. 1693
King County issued a request for consultant proposals 1694
in 2006 and recalled the request after a short time. 1695
The current status of the implementation of upgrades 1696
to the Black River Pump Station is unknown at this 1697
time. 1698
WSDOT believes that modifications to the BRPS 1699
would complement other watershed rehabilitation 1700
strategies such as riparian restoration, small barrier 1701
removal, floodplain restoration, and water quality 1702
improvements. 1703
What are the benefits and costs of implementing this concept? 1704
Exhibit 16 provides a summary of how plan 1705
implementation addresses limiting factors for 1706
salmonids in the watershed. 1707
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
CONCEPT DEVELOPMENT
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 54
1708
Exhibit 16. Benefits of the PCWRP as related to salmonid limiting factors in Panther
Creek/Springbrook Creek
Salmonid Limiting Factors
Lack of Salmonid
Refuge
Degraded Water Quality Lack of Functioning Riparian
Habitat
Fish Barriers
Establishes 0.50 AC
of off-channel
rearing habitat in
Panther Creek
wetland
Cascades to be provided in
new channel design (at
alluvial fan) to provide water
aeration and improve
dissolved oxygen
concentrations in Panther
Creek
Riparian shade tree plantings
to lower summer water
temperatures
7,750 LF (162,000 SF) of in-
channel improvements,
including 5,350 LF in Panther
Creek and 2,400 LF in
Springbrook Creek
36.9 acres of associated
floodplain improvements to
stream buffer/wetlands
including 12.8 acres of stream
buffer restoration to left bank of
east fork Panther Creek to
provide required buffer width
Removes 3
barriers to fish
passage (620 LF)
within Panther
Creek and
connects up to 3
miles of Panther
Creek riparian
habitat for fish use
Benefits of the
Panther Creek
Watershed
Rehabilitation Plan
Enhanced water quality
treatment of WSDOT
stormwater discharged to the
Panther Creek wetland
complex
1709
1710
The planning level cost to implement the watershed-1711
level stream mitigation plan is approximately $13.9 1712
million (See Break Out). 1713
The planning level cost (today’s dollar) for highway 1714
improvements in this area is $1.03 billion. The 1715
stormwater management (quantity and quality) portion 1716
of these highway costs, using conventional practices, 1717
is $46 million. The stormwater management cost 1718
providing a direct discharge of treated stormwater, as 1719
recommended in this PCWRP, is $29 million. 1720
1721
1722
1723
1724
What is the permitting strategy for this plan? 1725
WSDOT will partner with the City of Renton to obtain 1726
local permits and to work with the Multi-Agency 1727
Permitting Team (MAP Team) to obtain state and 1728
federal permits for the project. The MAP Team 1729
includes Washington State Department of Ecology, 1730
WDFW, WSDOT, U.S. Army Corps of Engineers, and 1731
King County Department of Development and 1732
How do project costs break out?
Stream Rehabilitation $5,075,000
Floodplain Improvements $2,413,000
Fish Passage Improvements $2,115,000
Springbrook Trail $906,000
Subtotal $10,509,000
Sales Tax (8.80%) $925,000
Contingency (10%) $1,051,000
PSE & Permitting (11%) $1,373,000
Grand Total $13,858,000
Costs are today’s dollar and are approximate, based on
conceptual design.
ROW costs are not included. It is assumed the City of
Renton will provide their Panther Creek wetland
property for the project.
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
CONCEPT DEVELOPMENT
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 55
Environmental Services. Permits expected to be 1733
needed include: Section 404, National Pollution 1734
Discharge Elimination System, Section 401 Water 1735
Quality Certification, Coastal Zone Management 1736
Consistency Determination and Hydraulic Project 1737
Approval. Tribal consultation will occur during the 1738
NEPA/SEPA and permitting processes. 1739
WSDOT will work in a partnership with the City of 1740
Renton to ensure that the project complies with the 1741
City’s Critical Areas Ordinances and obtains a 1742
Shoreline Substantial Development Permit for work 1743
near Springbrook Creek and a Public Works 1744
Construction Permit as needed. Also, any City 1745
easements within the project area will be reviewed. 1746
Early coordination with MAP Team, the City, U.S. Fish 1747
and Wildlife Service (USFWS), and NMFS will be 1748
critical in moving the project forward and providing the 1749
information necessary to obtain the required permits. 1750
The permit strategy is based on the following: 1751
• Depending on funding and the needs of these 1752
transportation projects, WSDOT will develop 1753
the permitting strategy that is most appropriate 1754
for optimum and timely delivery of the road 1755
improvement projects. 1756
• The rehabilitation sites currently owned by 1757
WSDOT are limited to the WSDOT ROW. The 1758
City of Renton owns or has easements for 1759
rehabilitation sites located within the Panther 1760
Creek wetland. None of the sites within the 1761
wetland are section 4(f) protected properties. 1762
Ownership of the remaining rehabilitation sites 1763
outside of this wetland complex is unknown at 1764
this time. It is also unknown if any of the 1765
rehabilitation sites are encumbered by land 1766
use restrictions that may preclude the 1767
proposed actions. 1768
• Rehabilitation site SR1 is currently regulated 1769
by King County Drainage District No. 1 1770
(KCDD1). Rehabilitation site SR2 also may be 1771
regulated by KCDD1. Coordination with 1772
KCDD1 would occur before finalizing 1773
rehabilitation sites SR1 and SR2. 1774
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
CONCEPT DEVELOPMENT
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 56
What are the next steps to move forward? 1775
A final AGREEMENT between the City of Renton and 1776
WSDOT for concept implementation will need to be 1777
reached. WSDOT ownership of the Concept sites is 1778
limited to WSDOT right-of-way. The City of Renton owns 1779
or has easements for areas located within the Panther 1780
Creek wetlands. 1781
Upon completion of the final AGREEMENT, Mitigation 1782
Report(s) in conformance with the WSDOT stream 1783
mitigation template (approximately 60 percent level of 1784
design) will be developed as standalone document(s) for 1785
the purpose of applying for permits. The Mitigation 1786
Report(s) will be identified as additional funding is 1787
obtained and include early coordination with MAP Team 1788
and the appropriate Tribes. At a minimum, the Mitigation 1789
Report will include contour grading plans and details, 1790
planting plans and details, construction and planting 1791
schedules and temporary erosion control plans and 1792
details. A site survey (including 1-foot contour 1793
information and location of areas of invasive species and 1794
individual significant trees) will be conducted. Additional 1795
information and studies required for the Mitigation Report 1796
may include: 1797
• Refined hydrologic modeling informed by 1798
fluvial geomorphology analysis 1799
• Geotechnical data collection (borings) and 1800
channel design recommendations 1801
• Groundwater data collection (piezometers 1802
and/or wells) 1803
• Sediment transport analysis featuring source 1804
and control/management recommendations 1805
The Mitigation Report will be submitted to the MAP 1806
Team to obtain the permits necessary for construction. 1807
The preparation of final construction documents would 1808
then follow as determined by I-405 Corridor project 1809
needs. 1810
1811
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
REFERENCES
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 57
R EFERENCES 1812
Published Documents 1813
Anchor Environmental 1814
2006 Fish Habitat Memorandum. Prepared by Derek Koellmann. 1815
Harza 1816
1995 Final Report Comprehensive Fisheries Assessment of Mill Creek, 1817
Garrison Creek and Springbrook Creek System. Pgs. 99-104 – Factors 1818
Limiting Salmon Production. 1819
HDR 1820
2006 Black River Pump Station Fish Passage Evaluation. January 2006. 1821
Hruby 1822
2004 Washington State Wetland Rating System for Western Washington – 1823
Revised. 1824
Jones & Stokes 1825
2005 WSDOT Panther Creek Wetlands Assessment. October 19, 2005. 1826
Kerwin, J. 1827
2001 Salmon and Steelhead Habitat Limiting Factors Report for the Cedar – 1828
Sammamish Basin (Water Resource Inventory Area 8), Washington 1829
Conservation Commission. Olympia, Washington. 1830
King County Department of Natural Resources (KCDNR) 1831
2000 Habitat Limiting Factors and Reconnaissance Assessment for Report 1832
Green/Duwamish and Central Puget Sound Watershed – Water Resource 1833
Inventory Area (WRIA) 9. Chapter 3.3 Springbrook Subbasin. 1834
2001 Distribution of Salmon and Trout Water Resource Inventory Area (WRIA) 1835
8 Lake Washington/Cedar/Sammamish Watershed [online] Available 1836
http://dnr.metrokc.gov/Wrias/8/fish-maps/distmap.htm, July 10, 2001. 1837
2005 Salmon Enhancement Plan: Making our Watershed Fit for a King – Green 1838
Duwamish and Central Puget Sound Watershed (WRIA) 9. Chapter 3.4 – 1839
Factors of Decline Specific to Subwatersheds. 1840
LaRiviere, Paul 1841
2006 Panther Creek Fish Passage Memorandum. January 12, 2006. 1842
National Oceanic Atmospheric Administration National Marine Fisheries Service (NMFS) 1843
1996 Habitat Publications & Related Guidance Documents – The Matrix Paper 1844
[Online] Available http://www.nwr.noaa.gov/Publications/Guidance-1845
Documents/Habitat.cfm. 1846
northwest hydraulic consultants (nhc) 1847
2006 Panther Creek Watershed Rehabilitation Memo. Tukwila to Renton 1848
Improvement Project. December 22, 2006. 1849
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
REFERENCES
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 58
2006 Fish Passage Evaluation at Central Panther Creek Outlet. February 17, 1850
2006. 1851
2005 Panther Creek Wetlands Supplemental Hydrologic December 23, 2005. 1852
2005 Part III of the South Renton Nickel Projects. May 19, 2005. 1853
RW Beck 1854
2006 Fish Passage at Selected Panther Creek Culverts. February 24, 2006. 1855
Renton, city of 1856
2005 SR 167 Alignment and Rainier Connection Recommendation. City of 1857
Renton Traffic Analysis Task Force. August 2005. 1858
1997 Eastside Green River Watershed Project Plan - Plan and Environmental 1859
Impact Statement. Prepared by RW Beck for the City of Renton. 1860
1992 Comprehensive Park, Recreation, and Open Space Plan. City of Renton. 1861
1991 City of Renton Trails Master Plan. 1862
U.S. Army Corps of Engineers (Corps) 1863
2000 Green/Duwamish River Basin Ecosystem Restoration Study. Final 1864
Feasibility Report. October 2000 1865
Washington State Department of Fish and Wildlife (WDFW) 1866
2005 Green/Duwamish and Central Puget Sound Watershed Salmon Habitat 1867
Plan. August 2005. 1868
2003 Design of Road Culverts for Fish Passage. May 2003. 1869
Washington State Department of Transportation (WSDOT) 1870
2006 Fish Passage at Evaluation at Central Panther Creek Outlet. Prepared by 1871
Matthew Gray. 1872
2006 Black River Pump Station Fish Passage Evaluation. January 2006. 1873
2005 I-405 Renton Nickel Improvement Project, I-5 to SR 169. Wetlands 1874
Discipline Report. Prepared by Adolfson. 1875
2005 I-405 Renton Nickel Improvement Project, I-5 to SR 169. Fisheries & 1876
Aquatic Resources Discipline Report. Prepared by Anchor 1877
Environmental. 1878
Wydosky, R.S. and R.R. Whitney 1879
1979 Inland fishes of Washington. University of Washington Press, Seattle, 1880
Washington. 1881
The Coot Company 1882
1989 P-9/Panther Creek Project Wetlands Inventory. June 29, 1989. 1883
The Watershed Company 1884
1989 Panther Creek Salmonid Fish Habitat Restoration May 10, 1989. 1885
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
REFERENCES
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 59
Personal Communications 1886
Paul LaRiviere, HDR personal communication with Jon Gage on January 11, 2006. 1887
1888
1889
PRELIMINARY DRAFT FOR MULTI-AGENCY PERMITTING TEAM (MAPT) REVIEW
REFERENCES
I-405 Water Resource Initiative at Panther Creek Wetlands
Panther Creek Watershed Rehabilitation Conceptual Plan 60
1890
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) B-1
Appendix B Essential Fish Habitat 4077
Background 4078
Public Law 104-297, the Sustainable Fisheries Act of 1996, amended the Magnuson-Stevens Fishery 4079
Conservation and Management Act to establish new requirements for Essential Fish Habitat (EFH) 4080
descriptions in federal fishery management plans and to require federal agencies to consult with the 4081
National Marine Fisheries Service (NMFS) on activities that may adversely affect EFH. 4082
4083
The Magnuson-Stevens Act requires all fishery management councils to amend their fishery 4084
management plans to describe and identify EFH for each managed fishery. The Pacific Fishery 4085
Management Council (1999) issued such an amendment in the form of Amendment 14 to the Pacific 4086
Coast Salmon Plan, and this amendment covers EFH for the Pacific salmon (Chinook salmon, coho 4087
salmon, and pink salmon) under NMFS jurisdiction that will potentially be affected by the Project. 4088
4089
EFH for Pacific salmon in freshwater includes all streams, lakes, ponds, wetlands, and other currently 4090
viable bodies of freshwater and the substrates within those waterbodies accessible to Pacific salmon. 4091
Activities occurring above impassable barriers that are likely to adversely affect EFH below 4092
impassable barriers are subject to the consultation provisions of the Magnuson-Stevens Act. 4093
4094
EFH for groundfish and coastal pelagic species includes all waters from the mean high water line along 4095
the coasts of Washington upstream to the extent of saltwater intrusion and seaward to the boundary of 4096
the U.S. exclusive economic zone (370.4 km.) (PFMC 1998a and 1998b). Designated EFH for 4097
salmonid species in estuarine and marine areas includes nearshore and tidally submerged environments 4098
within state territorial water out to the full extent of the exclusive economic zone (370.4 km.) offshore 4099
of Washington (PFMC 1999). 4100
4101
The Magnuson-Stevens Act requires consultation for all federal agency actions that may adversely 4102
affect EFH. EFH consultation with NMFS is required by federal agencies undertaking, permitting, or 4103
funding activities that may adversely affect EFH, regardless of its location. Under Section 305(b)(4) 4104
of the Magnuson-Stevens Act, NMFS is required to provide EFH conservation and enhancement 4105
recommendations to federal and state agencies for actions that adversely affect EFH. Wherever 4106
possible, NMFS utilizes existing interagency coordination processes to fulfill EFH consultations with 4107
federal agencies. For the proposed action, this goal is being met by incorporating EFH consultation to 4108
the Endangered Species Act (ESA) Section 7 consultation, as represented by this Biological 4109
Assessment (BA). 4110
4111
Indicate which of the Guilds listed below may be affected by project activities: 4112
Pacific Salmon Groundfish Coastal Pelagic Species 4113
4114
Location 4115
EFH in the action area includes the Green and Cedar Rivers and Springbrook, Panther, and Gilliam 4116
Creeks. Fall Chinook salmon are known to spawn in the lower Cedar River, rear in the Green River, 4117
and are known to be present in Springbrook Creek. Coho salmon are known to spawn in the lower 4118
Cedar River and rear in the Green River and Springbrook Creek. Pink salmon use is documented in 4119
the Green River (WDFW 2007). 4120
4121
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) B-2
Description of Project Activities 4122
The project activities covered by this assessment have been described in detail previously. Please refer 4123
to the following sections of the BA: 4124
2.1.4 Project Components 4125
2.1.5 Stormwater Treatment 4126
2.1.6 Fish Exclusion and Removal 4127
4128
Potential Adverse Effects of Project Activities 4129
The potential effects of project activities have been discussed in detail for some species of salmonids. 4130
Please refer to the following sections of the BA: 4131
4.1.1 Chinook Salmon 4132
4.1.2 Puget Sound Steelhead 4133
4.2.1 Bull Trout 4134
4135
Total impacts from the Project can be quantified as follows: 4136
4137
Impact Type Temporary Permanent
Below Ordinary High Water Mark 1.43 acres 1.69 acres
Shading 0.09 acres 0.86 acres
Riparian Buffers 0.91 acres 6.74 acres
4138
Impacts to groundfish and coastal pelagic guilds are not anticipated. The project takes place in 4139
freshwater and the action area does not extend to marine or estuarine waters. 4140
4141
Conservation Measures and Best Management Practices 4142
Conservation measures and BMPs are included for project activities, as described in the BA. 4143
Conservation measures will avoid or minimize potential impacts to existing habitat conditions, 4144
including EFH, within the project action area. Conservation Measures are provided in the following 4145
section of the BA: 4146
5.2 Summary of Conservation Measures 4147
4148
BMPs are provided in the following section of the BA: 4149
5.1 Summary of BMPs/Minimization Measures 4150
4151
In addition, the Design-Builder will be required to adhere to WSDOT Standard Specifications and 4152
performance standards that will further minimize impacts from Project construction. 4153
4154
Conclusions 4155
In accordance with the EFH requirements of the Magnuson-Stevens Fishery Conservation and 4156
Management Act, it has been determined that the project will have the following effect to EFH for the 4157
Guilds identified below: 4158
4159
Pacific Salmon No Adverse Affect Adverse Affect 4160
Chinook Salmon No Adverse Affect Adverse Affect 4161
Coho Salmon No Adverse Affect Adverse Affect 4162
Pink Salmon No Adverse Affect Adverse Affect 4163
Groundfish No Adverse Affect Adverse Affect 4164
Coastal Pelagic Species No Adverse Affect Adverse Affect 4165
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) B-3
4166
Explain the justification for this determination, or refer the reviewer to the BA for additional 4167
information: 4168
4169
Effects to designated critical habitat for Chinook salmon are detailed in Section 4.1.1 of the BA. This 4170
analysis serves as a valid effects analysis for EFH. 4171
4172
This project may adversely affect Pacific salmon EFH because of a permanent loss of habitat due to 4173
new in-water structures being placed within the OHWM of the Green River, where Chinook, coho, and 4174
pink salmon are all known to occur, and Springbrook Creek, where Chinook and coho salmon are 4175
known to occur. Chinook and coho salmon are documented to occur and spawn in the Cedar River, 4176
where EFH will be benefited by project activities. Pink salmon have not been documented to occur in 4177
Springbrook Creek and the Cedar River. 4178
4179
References 4180
Pacific Fisheries Management Council (PFMC). 1998a. The Coastal Pelagic Species Fishery 4181
Management Plan: Amendment 8. 4182
4183
PFMC. 1998b. Final Environmental Assessment/Regulatory Review for Amendment 11 to the Pacific 4184
Coast Groundfish Fishery Management Plan. 4185
4186
PFMC. 1999. Amendment 14 to the Pacific Coast salmon plan, Appendix A: Identification and 4187
description of Essential Fish Habitat, adverse impacts, and recommended conservation 4188
measures for salmon. Available: <http://www.psmfc.org/efh.html>. Accessed: June 18, 4189
2002. Pacific Fishery Management Council. Portland, OR. 4190
4191
Washington Department of Fish and Wildlife (WDFW) . 2007. SalmonScape interactive database. 4192
http://wdfw.wa.gov/mapping/salmonscape. Queried February 19, 2007. 4193
4194
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) C-1
Appendix C Species Lists from USFWS and NMFS 4195
4196
4197
Endangered and Threatened Species Under NMFS' Jurisdiction
List of Mammal Species under NMFS' Jurisdiction
(E = "endangered"; T = "threatened"; F = "foreign"; n/a = not applicable*)
Marine Mammals (20 listed "species")
Manatees and sea otters are also listed under the ESA, but fall under the jurisdiction of the U.S.
Fish and Wildlife Service.
Species
Year
Listed Status
Critical
Habitat*
Recovery
Plan*
Cetaceans
• blue whale
(Balaenoptera musculus)
1970 E n/a final
• bowhead whale
(Balaena mysticetus)
1970 E n/a no
• Chinese River dolphin
(Lipotes vexillifer)
1989 E (F) n/a n/a
• fin whale
(Balaenoptera physalus)
1970 E n/a draft
• gray whale (1 listed DPS)
(Eschrichtius robustus)
o Western North Pacific 1970 E n/a no
• Gulf of California harbor porpoise /
vaquita
(Phocoena sinus)
1985 E (F) n/a n/a
• humpback whale
(Megaptera novaeangliae)
1970 E n/a final
• Indus River dolphin
(Platanista minor)
1991 E (F) n/a n/a
• killer whale (1 listed DPS)
(Orcinus orca)
o Southern Resident 2005 E final proposed
• Northern right whale 1970 E final final
(Eubalaena glacialis)
• sei whale
(Balaenoptera borealis)
1970 E n/a no
• Southern right whale
(Eubalaena australis)
1970 E (F) n/a n/a
• sperm whale
(Physeter macrocephalus)
1970 E n/a draft
Pinnipeds
• Caribbean monk seal
(Monachus tropicalis)
1967 E n/a no
• Guadalupe fur seal
(Arctocephalus townsendi)
1985 T (F) n/a n/a
• Hawaiian monk seal
(Monachus schauinslandi)
1976 E final draft
revision
• Mediterranean monk seal
(Monachus schauinslandi)
1970 E (F) n/a n/a
• Saimaa seal
(Phoca hispida saimensis)
1993 E (F) n/a n/a
• Steller sea lion (2 listed DPSs)
(Eumetopias jubatus)
o Eastern 1990 T final draft
revision
o Western
original listing -
1997
1990
E
T
final draft
revision
* NOTE: Critical habitat and recovery plans are not required for foreign species; critical habitat is also
not required for species listed prior to the 1978 amendments adding critical habitat provisions to the
ESA.
List of Turtle Species under NMFS' Jurisdiction
(E = "endangered"; T = "threatened"; n/a = not applicable*)
Marine Turtles (8 listed "species")
Recovery plans for marine turtles are developed and implemented by NMFS and USFWS; the
plans have been written separately for turtles in the Atlantic and Pacific oceans (and East Pacific
for the green turtle) rather than for each listed species.
Species
Year
Listed Status
Critical
Habitat*
Recovery
Plan*
• green turtle (2 listed populations**)
(Chelonia mydas)
o Florida & Mexico's Pacific coast
breeding colonies
1978 E final final
o all other areas 1978 T final final
• hawksbill turtle
(Eretmochelys imbricata)
1970 E final final
• Kemp's ridley turtle
(Lepidochelys kempii)
1970 E n/a final
• leatherback turtle
(Dermochelys coriacea)
1970 E final final
• loggerhead turtle
(Caretta caretta)
1978 T n/a final
• olive ridley turtle (2 listed populations**)
(Lepidochelys olivacea)
o Mexico's Pacific coast breeding
colonies
1978 E n/a final
o all other areas 1978 T n/a final
* NOTE: Critical habitat and recovery plans are not required for foreign species; critical habitat is also
not required for species listed prior to the 1978 amendments adding critical habitat provisions to the
ESA.
** These populations were listed before the 1978 amendments to the ESA, which restricted
population listings to "distinct population segments of vertebrate species."
List of Fish Species under NMFS' Jurisdiction
(E = "endangered"; T = "threatened"; F = "foreign"; n/a = not applicable*)
Marine and Anadromous Fish (32 listed "species")
Species
Year
Listed Status
Critical
Habitat*
Recovery
Plan*
• Atlantic salmon (1 listed DPS)
(Salmo salar)
o Gulf of Maine 2000 E no final
• Chinook salmon (9 listed ESUs)
(Oncorhynchus tshawytscha)
o California coastal 1999** T final in process
o Central Valley spring-run 1999** T final in process
o Lower Columbia River 1999** T final in process
o Upper Columbia River spring-run 1999** E final draft
o Puget Sound 1999** T final final
o Sacramento River winter-run 1994** E final in process
o Snake River fall-run 1992** T final in process
o Snake River spring/ summer-run 1992** T final in process
o Upper Willamette River 1999** T final in process
• chum salmon (2 listed ESUs)
(Oncorhynchus keta)
o Columbia River 1999** T final in process
o Hood Canal summer-run 1999** T final in process
• coho salmon (3 listed ESUs)
(Oncorhynchus kisutch)
o Central California coast 2005** E final in process
original listing - 1996** T
o Lower Columbia River 2005** T in process in process
o Southern Oregon & Northern
California coasts
1997** T final in process
• green sturgeon (1 listed DPS)
(Acipenser medirostris)
o southern DPS 2006 T no no
• Gulf sturgeon
(Acipenser oxyrinchus desotoi)
1991 T final final
• shortnose sturgeon
(Acipenser brevirostrum)
1967 E n/a final
• sockeye salmon (2 listed ESUs)
(Oncorhynchus nerka)
o Ozette Lake 1999** T final in process
o Snake River 1991** E final in process
• smalltooth sawfish (1 listed DPS)
(Pristis pectinata)
o U.S. portion of range 2003 E no draft
• steelhead trout (10 listed DPSs)
(Oncorhynchus mykiss)
o Central California coast 1997** T final in process
o Snake River Basin 1997** T final in process
o Upper Columbia River 2006** T final draft
original listing - 1997** E
o Southern California 1997** E final in process
o Middle Columbia River 1999** T final in process
o Lower Columbia River 1998** T final in process
o Upper Willamette River 1999** T final in process
o Northern California 2000** T final in process
o South-Central California coast 1997** T final in process
o California Central Valley 1998** T final in process
• totoaba
(Totoaba macdonaldi)
1979 E (F) n/a n/a
* NOTE: Critical habitat and recovery plans are not required for foreign species; critical habitat is also
not required for species listed prior to the 1978 amendments adding critical habitat provisions to the
ESA.
** All Pacific salmonid listings were revisited in 2005 and 2006. Only the salmonids whose status
changed as a result of the review will show the revised date; for all others, only the original listing
date is shown. For more information on the listing history, please click on the link for each ESU/DPS.
List of Invertebrate and Plant Species under NMFS' Jurisdiction
(E = "endangered"; T = "threatened")
Marine Invertebrates (3 listed "species")
Species
Year
Listed Status
Critical
Habitat*
Recovery
Plan*
• elkhorn coral
(Acropora palmata)
2006 T no no
• staghorn coral
(Acropora cervicornis)
2006 T no no
• white abalone
(Haliotis sorenseni)
2001 E not
prudent
draft
Marine Plants (1 listed "species")
Species
Year
Listed Status
Critical
Habitat*
Recovery
Plan*
• Johnson's seagrass
(Halophila johnsonii)
1999 T final final
* NOTE: Critical habitat and recovery plans are not required for foreign species; critical habitat is also
not required for species listed prior to the 1978 amendments adding critical habitat provisions to the
ESA.
List of Species under NMFS' Jurisdiction Delisted or Proposed for Listing
Delisted Species
Species
Year
Listed
Year
Delisted Status
• gray whale (1 delisted DPS)
(Eschrichtius robustus)
o Eastern North Pacific 1970 1994 Delisted
from ESA; remains
protected under MMPA
Proposed for Listing
Species
Year
Proposed Status
• North Atlantic right whale 2006 proposed endangered
• North Pacific right whale 2006 proposed endangered
• steelhead trout (1 proposed DPS)
(Oncorhynchus mykiss)
o Puget Sound 2006 proposed threatened
Last updated 02/21/2007
ENDANGERED, THREATENED, PROPOSED, AND CANDIDATE SPECIES, CRITICAL
HABITAT, AND SPECIES OF CONCERN IN WESTERN WASHINGTON1
COMMON NAME SCIENTIFIC NAME RECOVERY PRIORITY
NUMBER
Endangered Animals
Brown pelican Pelecanus occidentalis 9
Columbian white-tailed deer Odocoileus virginianus leucurus 9c
Gray wolf Canis lupus 3c
Leatherback sea turtle Dermochelys coriacea 1
Short-tailed albatross Phoebastria albatrus 8
Endangered Plants
Bradshaw's desert-parsley Lomatium bradshawii 2
Marsh sandwort Arenaria paludicola 5
Threatened Animals
Bald eagle Haliaeetus leucocephalus 14c
Bull trout (Coastal-Puget Sound
and Columbia River DPS)
Salvelinus confluentus 9c
Canada lynx Lynx canadensis 15
Green sea turtle Chelonia mydas 1c
Grizzly bear Ursus arctos horribilis 3c
Loggerhead sea turtle Caretta caretta 7c
Marbled murrelet Brachyramphus marmoratus 2
Northern spotted owl Strix occidentalis caurina 3
Olive ridley sea turtle Lepidochelys olivacea 8c
Oregon silverspot butterfly Speyeria zerene hippolyta 3c
Western snowy plover Charadrius alexandrinus nivosus 3c
Threatened Plants
Golden paintbrush Castilleja levisecta 2
Kincaid's lupine Lupinus sulphureus ssp. Kincaidii 9
Nelson's checker-mallow Sidalcea nelsoniana 5
Water howellia Howellia aquatilis 7
Designated Critical Habitat
Marbled murrelet
Northern spotted owl
Western snowy plover, Pacific Coast Population
Bull Trout
Kincaid’s lupine
Proposed Species
Dolly Varden (Salvelinus malma) similarity of appearance
Proposed Critical Habitat
Revised marbled murrelet critical habitat
Western Washington Fish and Wildlife Office 1 Rev. 11/30/06
COMMON NAME SCIENTIFIC NAME LISTING PRIORITY
NUMBER
Candidate2 Animals
Fisher (West Coast DPS) Martes pennanti 6
Mardon skipper Polites mardon 5
Mazama pocket gopher Thomomys mazama (ssp. couchi,
glacialis, louiei, melanops,
pugetensis, tacomensis, tumuli,
yelmensis)
3
Oregon spotted frog Rana pretiosa 2
Streaked horned lark Eremophila alpestris strigata 3
Taylor's (Whulge or Edith's)
checkerspot butterfly
Euphydryas editha taylori 3
Yellow-billed cuckoo Coccyzus americanus 3
Candidate2 Plants
Northern wormwood Artemisia campestris ssp.
borealis var. wormskioldii
3
Animal Species of Concern3
Aleutian Canada goose Branta canadensis leucopareia
Beller's ground beetle Agonum belleri
California bighorn sheep Ovis canadensis californiana
California floater (mussel) Anodonta californiensis
California wolverine Gulo gulo luteus
Cascades frog Rana cascadae
Cassin's auklet Ptychoramphus aleuticus
Coastal cutthroat trout Oncorhynchus clarki clarki
Columbia pebblesnail Fluminicola columbianus
Columbia torrent salamander Rhyacotriton kezeri
Destruction Island shrew Sorex trowbridgii destructioni
Fender's soliperlan stonefly Soliperla fenderi
Fringed myotis (bat) Myotis thysanodes
Hatch's click beetle Eanus hatchi
Island large marble butterfly Euchloe ausonides insulanus
Larch Mountain salamander Plethodon larselli
Long-eared myotis Myotis evotis
Long-legged myotis Myotis volans
Makah's copper butterfly Lycaena mariposa charlottensis
Margined sculpin Cottus marginatus
Newcomb's littorine snail Algamorda newcombiana
Northern goshawk Accipiter gentilis
Northern sea otter Enhydra lutris kenyoni
Northwestern pond turtle Emys (= Clemmys) marmorata marmorata
Olive-sided flycatcher Contopus cooperi
Olympic torrent salamander Rhyacotriton olympicus
Oregon vesper sparrow Pooecetes gramineus affinis
Western Washington Fish and Wildlife Office 2 Rev. 11/30/06
COMMON NAME SCIENTIFIC NAME
Animal Species of Concern3
(Cont’d)
Pacific lamprey Lampetra tridentata
Pacific Townsend's big-eared bat Corynorhinus townsendii townsendii
Pale Townsend's big-eared bat Corynorhinus townsendii pallescens
Peregrine falcon Falco peregrinus
River lamprey Lampetra ayresi
Small-footed myotis Myotis ciliolabrum
Slender-billed white-breasted
nuthatch
Sitta carolinensis aculeata
Tailed frog Ascaphus truei
Tufted puffin Fratercula cirrhata
Valley silverspot butterfly Speyeria zerene bremnerii
Van Dyke's salamander Plethodon vandykei
Western gray squirrel Sciurus griseus griseus
Westslope cutthroat trout Oncorhynchus (=Salmo) clarki lewisi
Western toad Bufo boreas
Plant Species of Concern3
Barrett's beardtongue Penstemon barrettiae
Clackamas corydalis Corydalis aquae-gelidae
Clustered lady's slipper Cypripedium fasciculatum
Columbia yellow-cress Rorippa columbiae
Cotton's milk-vetch Astragalus australis var. olympicus
Footsteps of spring; bear's foot
sanicle
Sanicula arctopoides
Frigid shootingstar Dodecatheon austrofrigidum
Gorge daisy Erigeron oreganus
Howell's daisy Erigeron howellii
Obscure paintbrush Castilleja cryptantha
Oregon sullivantia Sullivantia oregana
Pale blue-eyed grass Sisyrinchium sarmentosum
Pale larkspur Delphinium leucophaeum
Pink sandverbena Abronia umbellata ssp. Acutalata
Queen of the forest Filipendula occidentalis
Rose checker-mallow Sidalcea malviflora ssp. Virgata
Seely's silene Silene seelyi
Stalked moonwort Botrychium pedunculosum
Tall bugbane Cimicifuga elata
Torrey's peavine Lathyrus torreyi
Triangular-lobed moonwort Botrychium ascendens
Whitebark pine Pinus albicaulis
White meconella Meconella oregana
White-top aster Sericocarpus rigidus
Western Washington Fish and Wildlife Office 3 Rev. 11/30/06
1Hyperlinks are provided for electronic recovery plans where available. Only recovery plans revised or
finalized since 1989 are available electronically. Alternate hyperlink to final rule listing the species is
substituted where available, or hyperlink connects to status information.
2Candidate species are those species for which FWS has sufficient information to propose for listing.
Hyperlinks are provided where available for electronic candidate forms or Federal Register notice of
petition finding.
3Species of concern are those species whose conservation status is of concern to FWS, but more
information is needed.
NOAA Fisheries threatened and endangered species list:
http://www.nmfs.noaa.gov/prot_res/species/ESA_species.html
Information for eastern Washington species can be found on the Upper Columbia Fish and Wildlife
Office web page and for all listed species on the U.S. Fish and Wildlife Service Endangered Species
Home Page.
Western Washington Fish and Wildlife Office 4 Rev. 11/30/06
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) D-1
Appendix D WSDOT Fish Removal Protocol and 4198
Standards 4199
Federal resource agencies have expressed an interest in the Washington State Department of 4200
Transportation (WSDOT) developing a work area isolation/fish removal protocol for agency activities 4201
where fish removal may be necessary. The following protocol was developed in an attempt to 4202
standardize WSDOT’s activities when they are required to remove fish from work areas. This protocol 4203
may not apply or may be modified in emergency situations or in certain areas that have unique site-4204
specific characteristics. 4205
4206
WSDOT Fish Removal Protocols and Standards 4207
Isolation of the work area, fish removal and release of fish shall be conducted or directed by a biologist 4208
who possesses the competence to ensure the safe handling of all Endangered Species Act (ESA) listed 4209
fish, and who is also experienced with work area isolation. 4210
4211
Isolation of the Work Area 4212
Installation of block nets will occur at predetermined locations, based on site characteristics, to prevent 4213
fish and other aquatic wildlife from moving into the work area. When selecting a suitable site look for 4214
an area that has desirable attributes such as slower flows, suitable locations for stake and/or gravel bag 4215
placement. Whenever conditions allow, the downstream block net shall be placed first. The upstream 4216
block net shall then be used as a seine to herd fish from the downstream block net location upstream to 4217
the point selected for the upstream block net installation. If feasible, this action will potentially move 4218
significant numbers of fish upstream, out of the impact area prior to other removal methods. If herding 4219
fish upstream is prohibitive because of flow velocities, installation of the upstream block net first, then 4220
the herding of fish downstream and installing the downstream block net may be effective. Both 4221
approaches have the added benefit of relocating fish without physically handling them. 4222
4223
Block net mesh size, length, type of material, and depth will vary based on site conditions. The 4224
directing biologist on site will base the design of block nets on specific site characteristics such as 4225
water depth, velocity and channel width. Typical block net material is 9.5 millimeter stretched mesh. 4226
Block nets shall remain in place until in-water work is completed. Block nets will require leaf and 4227
debris removal. An individual should be assigned the responsibility of frequently checking the nets to 4228
maintain their effectiveness and integrity. The frequency of such checks will be determined on a case-4229
by-case basis, dependent upon the system, season and weather conditions. An individual shall be 4230
stationed at the downstream block net continuously during electrofishing sessions, to recover stunned 4231
fish in the event they are washed downstream and pinned against the net. Block nets need to be 4232
secured along both banks and in-channel to prevent failure during unforeseen rain events or debris 4233
accumulation. Some locations may require additional block net support (examples include galvanized 4234
hardware cloth and metal fence posts). 4235
4236
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) D-2
Fish Removal 4237
Fish Collection 4238
The following methods provide alternatives for removal of fish from the area between the block nets. 4239
All other aquatic life encountered will also be released at an appropriate site. These methods are given 4240
in order of preference and for many locations a combination of methods will need to be applied. 4241
4242
The use of visual observation techniques (ex. snorkeling, surveying with polarized glasses or 4243
plexiglass bottomed buckets) should be considered for evaluation of removal method effectiveness and 4244
to identify specific locations of fish concentrations prior to removal attempts. Site specific project 4245
differences will determine the degree of aggressiveness in removal attempts. For instance, in areas 4246
where the streambed will be completely dewatered, highly aggressive techniques may be required to 4247
remove all fish and prevent death to individual fish due to suffocation and/or desiccation. In contrast, 4248
large unconfined areas where isolation is impossible and in-water work is limited to a very specific 4249
area, total removal of fish is likely impossible and possibly not necessary due to the ability of fish to 4250
relocate and avoid disturbance and associated impacts. Fish shall not be sampled during removal 4251
activities as this protocol is intended to address fish removal not research. Fish species, number and an 4252
age class estimate will be the default information that is documented. 4253
4254
Seining 4255
Use of a seine net shall be the preferred method. The remaining methods shall be used when seining is 4256
not possible or to enhance the effectiveness of seining. Seines made from 9.5 mm stretched nylon 4257
mesh shall be used to remove fish from the isolated stream reach. Seine design will be dependent upon 4258
site-specific characteristics. The on-site biologist will plan seining procedures based on an evaluation 4259
of site characteristics. 4260
4261
Small Dip Nets 4262
On projects where dewatering will occur, aquatic life will be collected by hand or with dip nets as the 4263
site is slowly dewatered. 4264
4265
Large Dip Nets 4266
Capture of fish by personnel in water or on shore using hand held nets when in water work will occur 4267
without dewatering (typically used in conjunction with seining). 4268
4269
Baited minnow traps (typically used in conjunction with seining). 4270
Electrofishing 4271
Electrofishing shall be performed only when other methods have been determined to be unfeasible or 4272
ineffective by the directing biologist. Electrofishing studies document injury rates to fish even at low 4273
settings. Therefore, use of this method is discouraged when unnecessary. The potential for injury to 4274
ESA-listed fish may outweigh the benefit of capture and relocation of all fish present in the work area. 4275
Electrofishing research results reveal a trend that as number of vertebrae and spine length increase, 4276
injury potential also increases. Therefore, the following guidelines are for juvenile ESA-listed fish and 4277
exclude adult ESA-listed fish. Areas where redds are present shall not be exposed to electrofishing 4278
activity. Capture and removal of adult ESA-listed fish will have to be accomplished using an alternate 4279
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) D-3
method other than electrofishing if herding them out of the area to be isolated is not possible. The 4280
following conditions shall apply to use of electrofishing as a means of fish removal: 4281
Electrofishing shall only be conducted when a biologist with at least 100 hours of electrofishing 4282
experience is on site to conduct or direct all activities associated with capture attempts. The directing 4283
biologist shall be familiar with the principles of electrofishing including the interrelated effects of 4284
voltage, pulse width and pulse rate on fish species and associated risk of injury/mortality. The 4285
directing biologist shall have knowledge regarding galvanotaxis, narcosis and tetany, their respective 4286
relationships to injury/mortality rates, and have the ability to recognize these responses when exhibited 4287
by fish. 4288
The following chart shall be used as guidelines for electrofishing in water where the potential to 4289
encounter ESA-listed juvenile fish exists. Visual observation of the size classes of fish in the work 4290
area is helpful to avoid injury to larger fish by the mistaken assumption that they are not present. 4291
4292
Initial Setting Conductivity (μS/cm) Maximum Settings
Voltage 100 V < 100 1100 V
100-300 800 V
> 300 400 V
Pulse Width 500 μs 5 ms
4293
Seasonal timing restrictions for conducting electrofishing shall be dependent upon the river system, 4294
fish composition and an analysis of the life history of documented species. Spawning adults and redds 4295
with incubating eggs should not be subjected to the effects of electrofishing. As a general rule, 4296
anadromous waters should not be electrofished from October 15 to May 15 and resident waters from 4297
November 1 to May 15. It shall be the responsibility of the directing biologist to research and assess 4298
the time of year (for each river segment) when electrofishing is appropriate. 4299
Each session shall begin with low settings for pulse width and pulse rate. If fish present in the area 4300
being electrofished do not exhibit an appropriate response the settings should be gradually increased 4301
until the appropriate response is achieved (galvanotaxis). Conducting electrofishing activity at the 4302
minimal effective settings is imperative because as pulse width and pulse rate increase, fish injury rates 4303
increase. Minimum effective voltage settings are dependent upon water conductivity and will need to 4304
increase as conductivity decreases. Higher voltages elevate the risk of serious injury to fish removal 4305
personnel. Use the lowest effective setting for pulse width, pulse rate and voltage to minimize 4306
personnel safety concerns and help minimize fish injury/mortality rates. 4307
The operator shall avoid allowing fish to come into contact with the anode. The zone of potential fish 4308
injury is 0.5 m from the anode. The directing biologist shall determine whether netting shall be 4309
attached to the anode. When site conditions allow use of an unnetted anode this method is preferred, 4310
due to the fact that this capture technique reduces mortality/injury rates. Techniques employed when 4311
using an unnetted anode keep fish farther from the anode and expose them to significantly less time in 4312
the zone of potential injury mentioned earlier. Extra care shall be taken near in-water structures, 4313
undercut banks, in shallow waters, or high-density fish areas. Voltage gradients may be abnormally 4314
intensified in these areas and fish are more likely to come into close contact with the anode. Consider 4315
lowering the voltage setting in shallow water sections. When electrofishing areas near undercut banks 4316
or where structures may provide cover for fish, use the anode to draw the fish out by placing the 4317
activated anode near the area fish are likely present and slowly draw the anode away. Fish 4318
experiencing galvanotaxis will be attracted to the anode and will swim away from the structure toward 4319
the anode so that they can be netted. This will not work on fish that experience narcosis or tetany. 4320
Therefore, fish response should be noted in adjacent areas prior to attempts made near structures. This 4321
should help avoid prolonged exposure of fish to the electrical field while in an immobilized state. 4322
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) D-4
Electrofishing shall be performed in a manner that minimizes harm to fish. Once an appropriate fish 4323
response (galvanotaxis) is noted, the stream segment shall be worked systematically, moving the anode 4324
continuously in a herringbone pattern through the water. Do not electrofish one area for an extended 4325
period of time. The number of passes shall be kept to a minimum, will be dependent upon site specific 4326
characteristics, and be at the discretion of the directing biologist. Adequate numbers of personnel shall 4327
be on-site to minimize the number of passes required for fish removal. Adequate staff to net, recover, 4328
and release fish in a prompt manner shall be present. Fish shall be removed from the electrical field 4329
immediately and recovered when necessary. Fish shall not be held in the net while continuing to 4330
capture additional fish. 4331
Carefully observe and document the condition of the captured fish. Dark bands on the body and 4332
extended recovery times are signs of injury or handling stress. When such signs are noted, the settings 4333
for the electrofishing unit and/or manner in which the electrofishing session is proceeding need 4334
adjustment. These characteristics may be an indication that electrofishing has become an inappropriate 4335
removal method for that specific site. Specimens shall be released immediately upstream of the block 4336
nets in an area that provides refuge. Each fish shall be capable of remaining upright and actively 4337
swimming prior to release (see Fish Release section). 4338
Electrofishing shall not occur when turbidity reduces visibility to less than 0.5 meters and shall not 4339
occur when water temperature is above 18°C or below 4°C. 4340
If the water conductivity exceeds 350 µS/cm electrofishing shall not occur. 4341
o Pumps used to temporarily bypass water around work sites shall be fitted with mesh 4342
screens to prevent aquatic life from entering the intake hose of the pump. The screen 4343
shall be installed as a precautionary measure to protect any fish and other wildlife, 4344
which may have been missed in the isolation and fish removal process. The screens 4345
will also prevent aquatic life from entering the intake hose if a block net should fail. 4346
Screens shall be placed approximately 2-4 feet from the end of the intake hose to assure 4347
fish are not pinned upon the screen. Screening techniques must be in compliance with 4348
Washington State Laws RCW 77.16.220, RCW 77.55.040 and RCW 77.55.070. 4349
o All fish shall be removed from stream crossing structures within the isolated stream 4350
reach. Connecting rod snakes may be used to help move fish out of the structure. The 4351
connecting rod snake is made of wood sections approximately three feet in length. 4352
When dewatering is to occur a seine may be placed at the downstream end of the 4353
crossing structure. As the water level goes down fish inside the culvert, in theory, will 4354
evacuate downstream into the seine that is in place at the outlet. The snake may be 4355
wiggled slowly through the pipe to encourage evacuation of fish out of the culvert. 4356
Other previously listed capture techniques shall be employed if required. 4357
4358
Fish Handling 4359
Fish Release 4360
For the period between capture and release, all captured aquatic life shall be immediately put into dark 4361
colored containers filled with clean stream water. Fish removal personnel shall provide: a healthy 4362
environment for the stressed fish; minimum holding periods; and low fish densities in holding 4363
containers to avoid effects of overcrowding. Large fish shall be kept separate from smaller prey-sized 4364
fish to avoid predation during containment. Water-to-water transfers shall occur whenever possible 4365
and the use of sanctuary nets is encouraged. Frequent monitoring of holding container temperature and 4366
well being of the specimens will be done to assure that all specimens will be released unharmed. 4367
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) D-5
Potential shade areas for fish holding periods and supplemental oxygen shall be considered in 4368
designing fish handling operations. 4369
4370
Captured aquatic life will be released in an appropriate area, designated by the directing biologist, that 4371
provides cover and flow refuge. The release site(s) will be determined by the directing biologist and 4372
may be based on specific site characteristics (flow and cover) and type of fish captured (out migrating 4373
smolt, kelt, prespawn migrating adult, etc). More than one site may be designated to provide for the 4374
varying migrational needs and to separate prey size fish from larger fish. The directing biologist shall 4375
consider fish migration requirements, size classes of fish and duration of work area isolation when 4376
designing fish release plans. Each fish shall be capable of remaining upright and have the ability to 4377
actively swim upon release. One person shall be designated to transport specimens in a timely manner 4378
to the site selected for release. All ESA-listed dead fish shall be preserved and delivered to the 4379
pertinent regulatory agency. All work area isolation, fish removal and fish release activity shall be 4380
thoroughly documented. Specifically, any injuries or mortalities to ESA-listed species shall be 4381
provided to National Marine Fisheries Service (NOAA fisheries) or United States Fish and Wildlife 4382
Service (USFWS), depending on which agency has jurisdiction over that species. 4383
4384
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) D-6
In-Water Work Fish Removal Monitoring Report 4385
Start Date: 4386
End Date: 4387
4388
Waterway: 4389
County: 4390
4391
Construction Activities: 4392
4393
4394
4395
4396
Number of fish observed: 4397
4398
Number of salmonid juveniles observed (include species): 4399
4400
Number of salmonid adults observed (include species): 4401
4402
What were fish observed doing prior to construction: 4403
4404
4405
What did the fish do during and after construction: 4406
4407
4408
Number of fish stranded as a result of this activity: 4409
4410
4411
How long were the fish stranded before they were captured and released to flowing water: 4412
4413
4414
Number of fish that were killed during this activity (include species): 4415
4416
4417
Send Report to: 4418
4419
National Marine Fisheries Service 4420
Washington State Habitat Branch 4421
Attn: Transportation Team 4422
510 Desmond Drive SE, Suite 103 4423
Lacey, WA 98503 4424
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) E-1
Appendix E Impacts to Aquatic Habitats and Green 4425
River Bridge Details 4426
The following is a description of how the impact areas in the graphics in this appendix were developed. 4427
To develop these impact numbers, the following assumptions were made: 4428
• Due to the design-build nature of the Project, the impacts shown in the graphics in this 4429
appendix represent a conservative estimate of impacts that will occur as a result of the project. 4430
• In areas where both permanent and temporary impacts will occur, only the permanent impacts 4431
were quantified to avoid counting impacts more than once. 4432
• For impacts on the Green River: 4433
o Permanent impacts below the ordinary high water mark (OHWM) of the Green River 4434
include those areas where permanent structures will be placed including piling and bank 4435
stabilization measures. Using the conservative approach detailed above, project 4436
engineers used the as-built drawings for the existing bridges over the Green River to 4437
determine the amount of existing bank stabilization and applied this to each new, 4438
widened, or reconstructed bridge. Bank stabilization for each bridge is assumed to 4439
continue down the bank to the bottom of the riverbed. The actual amount of required 4440
bank stabilization will be determined by a scour analysis performed by the Design-4441
Build Contractor. 4442
o Temporary impacts below the OHWM of the Green River include those areas where 4443
dewatering will occur. It is assumed that dewatering may need to occur simultaneously 4444
on both banks of the Green River to allow construction activities to be completed during 4445
the approved in-water work windows for the project. As dewatering may need to occur 4446
on both banks, it is further assumed that the channel between the dewatered areas may 4447
be constricted, stream velocities will increase through the constricted area, and 4448
associated temporary scouring may occur. Therefore, the entirety of the channel 4449
between the dewatered areas is identified as an area where temporary impacts may 4450
occur. 4451
o In areas where temporary impacts below the OHWM and permanent shade impacts 4452
occur, the area for both the temporary impacts below the OHWM and permanent shade 4453
impacts are included in the impact tables. In areas where permanent impacts below the 4454
OHWM and permanent shade impacts occur, only the permanent impacts below the 4455
OHWM impacts are included in the impact tables. 4456
o Impacts from new bank stabilization measures are not included in the impact tables in 4457
areas where the footprint of new bank stabilization measures overlaps with the footprint 4458
of existing bank stabilization measures (pre-project). 4459
• Impacts to the main channel of the east fork of Panther Creek are shown based on the present 4460
location of the east fork. It is assumed that the Panther Creek Watershed Rehabilitation Plan 4461
will be implemented as part of the project and that the main channel of Panther Creek will be 4462
merged with the west fork and relocated to meander toward the center of the wetland and outlet 4463
at the 23rd Street channel, prior to construction of the northbound SR 167 improvements that 4464
will impact the east fork of Panther Creek. 4465
• Impacts below the OHWM of the Cedar River are limited to the outfall pads associated with the 4466
reconstructed stormwater outfalls as described in the body of the biological assessment. 4467
1-121-132-102-102-113-103-111-12GP17405-62CULVERT EXTENDS THROUGHMODEL 201018_2_9GREEN RIVERGREEN RIVERGREEN RIVERGREEN RIVER2-123-103-12STSTSTST C17C1646094.00sq.ft.xxxPH1:\005\Environmental\Calcs\Exhibits\BA_wetland_impact_sht_ 01.dgndbrinkman3:18:04 PM5/30/2007Department of TransportationWashington StateINTERSTATE405Corridor ProgramIMPACT LINE LEGENDWETLAND IMPACT LEGENDSTREAM IMPACT LEGENDPERMANENT IMPACTTEMPORARY IMPACTPERMANENT BUFFER IMPACTTEMPORARY BUFFER IMPACT1 OF 5SCALE IN FEET0200100IMPACT LINESTREAM LINE (OPEN CHANNEL)STREAM LINE (CLOSED CHANNEL)SURVEYED WETLANDBUFFERTUKWILA TO RENTONIMPROVEMENT PROJECTWETLAND AND STREAM IMPACTSPERMANENT IMPACTTEMPORARY IMPACTPERMANENT BUFFER IMPACTTEMPORARY BUFFER IMPACTPERMANENT SHADINGTEMPORARY SHADINGPERMANENT OHWMTEMPORARY OHWMDEWATERING LENGTHGREENRIVER
I-405SR 181PARKWAYTUKWILA GILLIAM CREEK
13-1113-11GP17167-9313-1113-1214-12GP17167-9313-1214-1213-1314-13405-015405-016FUEL PUMP13-1313-14405-016CELL PHONETOWER14-1413-1414-15NOTEMarsh limit line is approximatedue to dense brush & trees14-15C66C65PH1:\005\Environmental\Calcs\Exhibits\BA_wetland_impact_sht_ 02.dgndbrinkman5:13:35 PM5/30/2007Department of TransportationWashington StateINTERSTATE405Corridor ProgramIMPACT LINE LEGENDWETLAND IMPACT LEGENDPERMANENT IMPACTTEMPORARY IMPACTPERMANENT BUFFER IMPACTTEMPORARY BUFFER IMPACTSCALE IN FEET02001002 OF 5SR 167PH1:\005\Environmental\Calcs\Exhibits\BA_wetland_impact_sht_ 02.dgnIMPACT LINESTREAM LINE (OPEN CHANNEL)STREAM LINE (CLOSED CHANNEL)SURVEYED WETLANDBUFFERTUKWILA TO RENTONIMPROVEMENT PROJECTWETLAND AND STREAM IMPACTSSW 43TH STSTREAM IMPACT LEGENDPERMANENT IMPACTTEMPORARY IMPACTPERMANENT BUFFER IMPACTTEMPORARY BUFFER IMPACTPERMANENT SHADINGTEMPORARY SHADINGPERMANENT OHWMTEMPORARY OHWMDEWATERING LENGTHPANTHER CREEKWEST FORKPANTHER CREEKEAST FORK
405-021405-021405-0208-108-1113-1813-1714-1814-19NOTEMarsh limit line is approximatedue to dense brush & treesNOTEMarsh limit line is approximatedue to dense brush & treesDense TreesDense TreesDense TreesDense TreesDense TreesDense Trees14-1713-15M.P. 25.00NOTEMarsh limit line is approximatedue to dense brush & treesGP17167-94405-31613-1513-1614-1614-17Dense TreesDense TreesDense TreesNOTEMarsh limit line is approximatedue to dense brush & treesDense TreesDense Trees13-1713-1614-1614-1814-17GP17167-94405-316Dense TreesDense TreesDense TreesDense TreesDense TreesNOTEMarsh limit line is approximatedue to dense brush & treesDense TreesDense TreesSubstationSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTST
PH1:\005\Environmental\Calcs\Exhibits\BA_wetland_impact_sht_ 03.dgndbrinkman5:16:59 PM5/30/2007
3 OF 5SR 167TUKWILA TO RENTONIMPROVEMENT PROJECTWETLAND AND STREAM IMPACTSEAST VALLEY ROADSW 27TH STDepartment of TransportationWashington StateINTERSTATE405Corridor ProgramIMPACT LINE LEGENDWETLAND IMPACT LEGENDPERMANENT IMPACTTEMPORARY IMPACTPERMANENT BUFFER IMPACTTEMPORARY BUFFER IMPACTSCALE IN FEET0200100IMPACT LINESTREAM LINE (OPEN CHANNEL)STREAM LINE (CLOSED CHANNEL)SURVEYED WETLANDBUFFERSTREAM IMPACT LEGENDPERMANENT IMPACTTEMPORARY IMPACTPERMANENT BUFFER IMPACTTEMPORARY BUFFER IMPACTPERMANENT SHADINGTEMPORARY SHADINGPERMANENT OHWMTEMPORARY OHWMDEWATERING LENGTHPANTHER CREEKEAST FORK
Parking LotGateGateGateGate4002DenseBrushDenseBrushParking LotPipeDense TreesPipe4002405-042Dense TreesDense TreesDavisAve S405-0422-192-192-20PoolDense Trees2-202-21405-042NOTEMarsh limit line is approximatedue to dense brush & treesDense TreesDense TreesDense TreesBrush2-213-21405-042Dense Trees3-19Dense Trees405-023Parking Lot3-203-193-203-19405-02313-19NOTEMarsh limit line is approximatedue to dense brush & treesDense TreesDense Trees13-203-21Dense TreesNOTEMarsh limit line is approximatedue to dense brush & treesDense Trees405-02313-1913-203-21UDUDUDUDUDUDUDUDUDUDUDUD C76C73C72PH1:\005\Environmental\Calcs\Exhibits\BA_wetland_impact_sht_ 04.dgndbrinkman5:19:31 PM5/30/2007
4 OF 4SR 167TUKWILA TO RENTONIMPROVEMENT PROJECTWETLAND AND STREAM IMPACTSDepartment of TransportationWashington StateINTERSTATE405Corridor ProgramIMPACT LINE LEGENDWETLAND IMPACT LEGENDPERMANENT IMPACTTEMPORARY IMPACTPERMANENT BUFFER IMPACTTEMPORARY BUFFER IMPACTSCALE IN FEET0200100IMPACT LINESTREAM LINE (OPEN CHANNEL)STREAM LINE (CLOSED CHANNEL)SURVEYED WETLANDBUFFERSTREAM IMPACT LEGENDPERMANENT IMPACTTEMPORARY IMPACTPERMANENT BUFFER IMPACTTEMPORARY BUFFER IMPACTPERMANENT SHADINGTEMPORARY SHADINGPERMANENT OHWMTEMPORARY OHWMDEWATERING LENGTHPANTHER CREEKEAST FORKEAST VALLEY ROADSW 19TH ST
ROLLING HILLS CREEK
Parking LotRRRRTankRR RRRRRRFire Access Only
46094.00sq.ft.PH1:\005\Environmental\Calcs\Exhibits\BA_wetland_impact_sht_ 05.dgndbrinkman2:29:28 PM5/30/2007Department of TransportationWashington StateINTERSTATE405Corridor ProgramIMPACT LINE LEGENDWETLAND IMPACT LEGENDSTREAM IMPACT LEGENDPERMANENT IMPACTTEMPORARY IMPACTPERMANENT BUFFER IMPACTTEMPORARY BUFFER IMPACT5 OF 5SCALE IN FEET0200100IMPACT LINESTREAM LINE (OPEN CHANNEL)STREAM LINE (CLOSED CHANNEL)SURVEYED WETLANDBUFFERTUKWILA TO RENTONIMPROVEMENT PROJECTWETLAND AND STREAM IMPACTSPERMANENT IMPACTTEMPORARY IMPACTPERMANENT BUFFER IMPACTTEMPORARY BUFFER IMPACTPERMANENT SHADINGTEMPORARY SHADINGPERMANENT OHWMTEMPORARY OHWMDEWATERING LENGTHCEDARRIVERI-40
5 CEDAR RIVERPARKLIBERTYPARK
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) F-1
Appendix F Stormwater Pollutants 4470
4471
Cadmium (Cd) 4472
Cadmium is a relatively rare, naturally occurring metal. Naturally, its initial route of entry to the 4473
environment is often via the atmosphere or through the weathering of rocks, soil and volcanoes. 4474
However, these sources are minor compared with anthropogenic sources. Anthropogenic sources 4475
associated with the transportation system include lubricants, automobile exhaust, tire wear, galvanized 4476
steel, and pesticides. Cadmium is found as Cd2+ in water (Callahan et al., 1979). 4477
4478
Cadmium particulates that settle on the roadway from automobiles and dry and wet atmospheric 4479
deposition will become part of stormwater runoff. According to past WSDOT NPDES reports and the 4480
International BMP Database (http://www.bmpdatabase.org/), cadmium is rarely detected in stormwater 4481
above analytical detection limits. Cadmium that is present in stormwater is found in very low 4482
concentrations. 4483
4484
Cadmium that becomes part of runoff is rapidly adsorbed onto particulate matter (Callahan et al., 4485
1979) and will be filtered or settled out in appropriate types of BMPs, such as those BMPs that filter or 4486
settle out solids and uses organic material as a filter or “sink” (i.e. ponds, vegetated swales, ecology 4487
embankments). Adsorption increases with pH and the organic content of the soil. Therefore leaching is 4488
more apt to occur under acidic conditions in sandy soil (SRC, 1999). Cadmium may also precipitate as 4489
the carbonate or be adsorbed by or coprecipitate with hydrous iron, aluminum, and manganese oxides 4490
(SRC, 1999). Many plants have the ability to accumulate cadmium, primarily in the roots, but also in 4491
the stem and leaves (McCracken, 1987). Cadmium does not form volatile compounds in the aquatic 4492
environment (Callahan et al., 1979); therefore, volatilization from water is not a significant fate 4493
process. 4494
4495
Cadmium that is not removed in a BMP and enters surface water is rapidly adsorbed onto particulate 4496
matter and settles out. Studies have shown that cadmium concentrations in bed sediment are at least an 4497
order of magnitude higher than in the overlying water (Callahan et al., 1979). The uptake of cadmium 4498
by many aquatic invertebrates can be appreciable (McCracken, 1987). Cadmium is taken up in fish 4499
both from the water and in their diets. However, studies have shown that water is the primary source of 4500
uptake with diet playing a minor role (McCracken, 1987). In fish, the gill is a key site for metals 4501
uptake, but organs such as the liver and kidney can become susceptible as the contaminant is 4502
detoxified and eliminated (Riddell et al., 2005). Riddell et al (2005) determined in a study using an 4503
experimental aquatic food web, that exposures of 0.5ug/L Cd can have sublethal effects on brook trout 4504
(S. fontinalis), but also noted a species-specific cadmium tolerance between test species. Studies 4505
comparing the cadmium toxicity in bull trout to current regulatory water quality standards have 4506
suggested that the recently revised US federal Aquatic Life Criteria value for the protection of aquatic 4507
biota will be protective of sensitive ESA-listed species (Hansen et al., 2002). The ALC values are a 4508
function of water chemistry and can be found at http://www.epa.gov/waterscience/criteria/aqlife.html. 4509
4510
Lead (Pb) 4511
Lead is the fifth most prevalent metal commercially in the United States. Anthropogenic sources 4512
associated with the transportation system include bridge paint, automobile exhaust, tire wear, 4513
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) F-2
lubricating oil & grease, and bearing wear. Pb2+ is the stable ionic species of lead and readily binds to 4514
organic compounds in the natural environment. 4515
4516
Lead particulates that settle on the roadway from automobiles will become part of stormwater runoff. 4517
According to past WSDOT NPDES reports and the International BMP Database 4518
(http://www.bmpdatabase.org/), lead is rarely detected in stormwater above analytical detection limits. 4519
Lead that is present in stormwater is found in very low concentrations. 4520
4521
Lead that becomes part of runoff is effectively removed from the water column to the sediment by 4522
adsorption to organic matter and clay minerals, precipitation as insoluble salt (carbonate, sulfate, or 4523
sulfide), and reaction with hydrous iron, aluminum, and manganese oxides (SRC, 1999b). Only a small 4524
fraction of lead in soil appears to be in water-soluble form (Khan, 1983). In soil, lead is relatively 4525
immobile and can persist for long periods of time (USEPA, 1979). The efficient fixation of lead by 4526
most soils greatly limits the transfer of lead to aquatic systems and also inhibits absorption of lead by 4527
plants (Kayser et al., 1982). Lead is tightly bound to most soils with virtually no leaching under most 4528
conditions (Zimdane and Hassett, 1977). Lead is most available from acidic sandy soils which contain 4529
little material capable of binding lead (NRCC, 1978). Due to its very low vapor pressure and 4530
insolubility, volatilization of lead from soil or water will be negligible (SRC, 1999b). BMPs that filter 4531
or settle out particulate matter will be effective at removing lead from the runoff (i.e. ponds, vegetated 4532
swales, etc.). 4533
4534
Lead that is not removed via BMPs and is introduced into the aquatic environment is associated with 4535
particulate matter that settles down into the sediments (Botelho, 1994). However, biomethylation of 4536
lead by benthic microorganisms can lead to its remobilization and reintroduction of lead into the 4537
aqueous environment (Schulz-Baldes, 1983). Cycling of lead in estuaries involves a complex exchange 4538
between dissolved and particulate phases (Elbaz-Poulichet, 1984). It has been demonstrated that Pb0 4539
and Pb2+ can be oxidatively methylated by naturally occurring compounds resulting in the dissolution 4540
of lead already bound to sediment or particulate matter (Craig and Rapsomanikis, 1985). 4541
4542
Aquatic biota, both invertebrate and vertebrate, have been shown to bioconcentrate lead at levels 4543
greater than are present in water and sometimes similar to those levels present in sediments. However, 4544
the concentration of lead tends to decrease with increasing trophic levels in aquatic systems (USEPA, 4545
1979). Lead does not appear to bioconcentrate significantly in fish but does in some shellfish such as 4546
mussels (SRC, 1999b). Fish do not appear to accumulate lead as readily as the invertebrate species 4547
they may eat (Kayser, et al., 1982). Multiple studies (MacDonald et al., 2002; Schwartz et al., 2004) 4548
have shown that metal toxicity to aquatic species varies with water chemistry and other environmental 4549
factors. 4550
4551
Chromium (Cr) 4552
Chromium is a widely distributed metal in the earth’s crust, but is rare in unpolluted waters (SRC, 4553
2002). Chromium’s valence states range from Cr2- to Cr6+, but the important valence states of 4554
chromium are the trivalent state [Cr(III)] and the hexavalent state [Cr(VI)]. Chromium compounds are 4555
stable in the trivalent state and the hexavalent state is the second most stable state. Hexavalent 4556
chromium rarely occurs naturally, but is produced from anthropogenic sources. Chromium compounds 4557
are released into the atmosphere mainly by anthropogenic sources. Naturally occurring gaseous forms 4558
of chromium are rare (Carey, 1982). Anthropogenic sources associated with the transportation system 4559
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) F-3
include metal plating, moving engine parts, and brake lining wear, and via the combustion of natural 4560
gas and oil. 4561
4562
Chromium particulates that settle on the roadway from dry and wet atmospheric deposition will 4563
become part of stormwater runoff. The Caltrans runoff characterization study at 4564
(http://www.dot.ca.gov//hq/env/stormwater/special/newsetup/_pdfs/monitoring/CTSW-RT-03-4565
065.pdf) indicates that chromium is a low monitoring priority because the estimated percent 4566
exceedence of untreated runoff with California standards is 0.01%. 4567
4568
Chromium will be as soluble and insoluble forms. Most of the soluble chromium is present as Cr(VI) 4569
but this generally accounts for only a few percent of the total (Carey, 1982). Chromium that becomes 4570
part of runoff is generally removed from the water column to the sediment by adsorption (Carey, 4571
1982). BMPs that filter or settle out particulate matter may be effective at removing chromium from 4572
runoff (i.e. ponds, vegetated swales, etc.). 4573
4574
Adsorption of chromium to sediment varies with water chemistry, but Cr(III) tends to be the most 4575
prevalent in sediment; occurring mostly as suspended solids adsorbed onto clay material, organics, or 4576
iron oxide present in water (Carey, 1982). Adsorption of Cr(III) increases with pH (Bodek, 1988; 4577
Fukai, 1967). Cr(VI) is water soluble and a strong oxidant (Carey, 1982). In the Columbia River, 4578
dissolved Cr(III) generally accounts for only 3% of the dissolved chromium and Cr(VI) accounts for 4579
over 90% (added by atomic reactor cooling water) (Carey, 1982). 4580
4581
As pH decreases, adsorption of Cr(VI) to sediment increases (Saleh et al., 1989). Organic matter in 4582
soils reduces Cr(VI) to Cr(III) spontaneously. On the other hand, Cr(III) can oxidize to Cr(VI). 4583
However, oxidation of Cr(III) will not be significant in most natural waters because dissolved oxygen 4584
by itself in natural waters does not cause any measurable oxidation of Cr(III) to Cr(VI) (Saleh et al, 4585
1989). 4586
4587
Based on the above information, most chromium compounds that are discharged into receiving waters 4588
will ultimately be deposited in sediments. Generally, there is little tendency for Cr(III) to accumulate 4589
along food chains (NRCC, 1976). Bottom-dwelling fish like, flounder are known to accumulate Cr(VI) 4590
(Calamari et al., 1982); however, chromium is not expected to biomagnify in the aquatic food chain 4591
(SRC, 2002). 4592
4593
Polycyclic Aromatic Hydrocarbons (PAHs) 4594
Polycyclic aromatic hydrocarbons (PAHs) are organic substances made up of carbon and hydrogen 4595
atoms grouped into at least two condensed aromatic rings structures. These are divided into two 4596
categories: low molecular weight compounds composed of fewer than four rings and high molecular 4597
weight compounds of four or more rings. Anthropogenic sources associated with the transportation 4598
system include automobile exhaust, atmospheric deposition, and creosote-treated products. 4599
4600
PAHs that settle on the roadway from atmospheric deposition will become part of stormwater runoff. 4601
However, Caltrans concluded that tested PAHs were a low monitoring priority because they were 4602
either never detected, or had an estimated percent exceedence with California standards of <0.01% in 4603
untreated stormwater 4604
(http://www.dot.ca.gov//hq/env/stormwater/special/newsetup/_pdfs/new_technology/CTSW-RT-01-4605
050.pdf). 4606
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) F-4
4607
PAHs that become part of runoff are expected to adsorb to suspended solids and sediment. In general, 4608
PAHs with higher molecular weights are almost completely adsorbed onto fine particles and are 4609
expected to be immobile in soil. Lower molecular weight PAHs are partially adsorbed and are 4610
expected to have slight to no mobility in soil (ATSDR, 1995). BMPs that filter or settle out particulate 4611
matter may be effective at removing PAHs from the runoff (i.e. ponds, vegetated swales, etc.). 4612
4613
PAHs that are introduced to the aquatic environment via runoff are generally associated with sediment 4614
and may accumulate over time. In aquatic environments, low molecular weight PAHs generally 4615
biodegrade relatively rapidly (SRC). In soil, degradation of PAHs with 3 rings generally takes weeks 4616
to months and is primarily accomplished by action of microorganisms (SRC, 2003). Also, PAHs with 3 4617
rings exist predominately in the vapor phase (WHO, 1998; ATSDR, 1995). 4618
4619
PAHs with 4 or more rings are generally resistant to biodegradation (SRC, 2003). PAHs with 4 rings 4620
can exist in both vapor and particulate phase and those with 5 or more rings exist predominately in the 4621
particulate phase (WHO, 1998; ATSDR, 1995); therefore volatilization of high molecular weight 4622
PAHs is not expected to be an important fate process. PAHs are not expected to volatilize from dry soil 4623
surfaces (SRC, 2003). Bioaccumulation by aquatic organisms is also greater for higher molecular 4624
weight PAHs than for lower molecular weight PAHs (ATSDR, 1995). 4625
4626
Summary of Risk from Cadmium, Lead, Chromium, and PAH 4627
Compounds in Stormwater Associated with WSDOT projects. 4628
Stormwater associated with highway runoff may contain low levels of cadmium, lead, chromium, and 4629
PAH compounds. Often, these compounds are below levels that can be detected with current analytical 4630
methods and may be effectively filtered or settled out in stormwater BMPs prior to being discharged to 4631
nearby waterbodies. Based on the environmental chemistry and biological fate of these compounds in 4632
an aquatic system, exposure to ESA-listed species is expected to be small. 4633
4634
4635
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) G-1
Appendix G Environmental Baseline for Aquatic 4636
Habitats 4637
1.1 Water Quality 4638
1.1.1 Water Temperature: 4639
Briefly describe the current condition of this indicator at both the watershed scale and the 4640
project action area scale: 4641
Temperature conditions in the Lower Green River Subwatershed are not properly functioning per
the National Marine Fisheries Service (NMFS) Matrix of Pathways and Indicators for salmonids
and functioning at unacceptable risk per the U.S. Fish and Wildlife Service (USFWS) Matrix of
Diagnostics/Pathways and Indicators for bull trout. The Green River and Cedar River are
currently on the Washington State Department of Ecology (Ecology) 303(d) list for exceeding
allowable water quality criteria for temperature. Temperature information is not available for the
remaining streams in the Project area.
Temperature characterization information has been identified as a data gap in the Lower Cedar
River Subarea.
4642
The project will: Improve Maintain Degrade, or Temporarily degrade this 4643
indicator 4644
4645
Briefly describe how, at both the watershed scale and the project action area scale: 4646
Overall impervious surfacing in the impacted watersheds will increase by a net 69.60 acres as a
result of the Project. Stormwater facilities will be constructed to collect stormwater from an area
greater than all new impervious surfaces resulting from the Project. As a result of the increased
impervious surfacing, stormwater inputs into selected waterbodies in the Project area during peak
summer temperatures are anticipated to marginally increase water temperatures near the new
stormwater outfalls associated with the Project; however, storm events during peak temperatures
are anticipated to be rare.
4647
1.1.2 Sediment/Turbidity: 4648
Briefly describe the current condition of this indicator at both the watershed scale and the 4649
project action area scale: 4650
Sediment/turbidity conditions in the Lower Green River Subwatershed are not properly
functioning per the NMFS Matrix of Pathways and Indicators for salmonids and functioning at
unacceptable risk per the USFWS Matrix of Diagnostics/Pathways and Indicators for bull trout.
Sediment/turbidity information has been identified as a data gap in the Lower Cedar River
Subarea. No data were available for the duration of exposure, so it is difficult to determine the
extent to which total suspended solids (TSS) are of concern (Kerwin 2001). Stream channel
erosion is common in the steeper gradient portions of Panther Creek and Springbrook Springs
tributary where excess runoff from development has accelerated natural erosion processes.
Sediment deposits in the lower section of Springbrook Springs have reached depths of five feet
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) G-2
(Kerwin 2000).
4651
The project will: Improve Maintain Degrade, or Temporarily degrade this 4652
indicator 4653
4654
Briefly describe how, at both the watershed scale and the project action area scale: 4655
Temporary increases in turbidity may occur at the action area scale as a result of construction-
related activities, but a Temporary Erosion and Sediment Control (TESC) and associated erosion
control best management practices (BMPs) will be designed and implemented to minimize these
impacts. Increases in turbidity at a watershed scale are expected to be negligible.
Stormwater facilities constructed for the Project will also reduce sediment levels through enhanced
stormwater treatment.
1.1.3 Chemical Contamination/Nutrients: 4656
Briefly describe the current condition of this indicator at both the watershed scale and the 4657
project action area scale: 4658
Chemical contamination/nutrients conditions in the Lower Green River Subwatershed are not
properly functioning per the NMFS Matrix of Pathways and Indicators for salmonids and
functioning at unacceptable risk per the USFWS Matrix of Diagnostics/Pathways and Indicators
for bull trout.
The Green River, Cedar River, and Springbrook Creek are currently on Ecology’s 303(d) list for
exceeding allowable water quality criteria for fecal coliform. Additionally, the Green River and
Springbrook Creek are currently on the 303(d) list for DO.
The majority of the ambient metals data in the Cedar River Subarea were collected as part of the
stormwater monitoring program; therefore, baseflow metals concentrations are generally unknown
(Kerwin 2001).
4659
The project will: Improve Maintain Degrade, or Temporarily degrade this 4660
indicator 4661
4662
Briefly describe how, at both the watershed scale and the project action area scale: 4663
Stormwater discharges to the streams and rivers of the action area will comply with water quality
regulations in accordance with the Washington State Department of Transportation (WSDOT)
Highway Runoff Manual (HRM; WSDOT 2004). New storm drainage systems related to the
Project will collect runnoff from an area greater than all new impervious surfacing created by the
Project. Where applicable, runoff from this area will be treated for enhanced water quality before
being discharged into streams or rivers per the HRM. Enhanced treatment, as defined in the HRM,
provides a higher rate of removal of dissolved metals than basic treatment facilities for influent
concentrations ranging from 0.003 to 0.02 milligrams per liter (mg/L) for dissolved copper and
0.02 to 0.3 mg/L for dissolved zinc. The enhanced treatment will result in fewer contaminants
entering the waterbodies in the Project area.
4664
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) G-3
1.2 Habitat Access 4665
1.2.1 Physical Barriers: 4666
Briefly describe the current condition of this indicator at both the watershed scale and the 4667
project action area scale: 4668
Physical barrier conditions in the Lower Green River Subwatershed and the Lower Cedar River
Subarea are not properly functioning per the NMFS Matrix of Pathways and Indicators for
salmonids and functioning at unacceptable risk per the USFWS Matrix of Diagnostics/Pathways
and Indicators for bull trout.
In the action area, WSDOT has identified which culverts in the action area convey waters of the
state, are fish bearing, and where in-water work as a result of the project will occur. Based on the
results of the fish passage barrier investigation, WSDOT has determined that there are ten culverts
that meet these criteria. Of these ten culverts, WSDOT has determined that seven of them are
existing fish passage barriers (WSDOT 2007). WSDOT will conduct further evaluation on the
seven fish barrier culverts to determine which ones will be retrofitted or replaced as part of the
project.
4669
The project will: Improve Maintain Degrade, or Temporarily degrade this 4670
indicator 4671
4672
Briefly describe how, at both the watershed scale and the project action area scale: 4673
Physical barrier conditions are not anticipated to significantly change at either the watershed or
project action area scale as a result of the Project. Fish passage decisions have not been made for
this project at this time.
4674
1.3 Habitat Elements 4675
1.3.1 Substrate: 4676
Briefly describe the current condition of this indicator at both the watershed scale and the 4677
project action area scale: 4678
Substrate conditions in the Lower Green River Subwatershed and the Lower Cedar River Subarea
are not properly functioning per the NMFS Matrix of Pathways and Indicators for salmonids and
functioning at unacceptable risk per the USFWS Matrix of Diagnostics/Pathways and Indicators
for bull trout.
In the Lower Green River Subwatershed, channelization and confinement of the channel between
levees prevent high flows from accessing the floodplains, reducing groundwater recharge.
Narrow, deeper channels have higher water velocity and bed shear stress, thus even small flood
events may scour streambed materials (Kerwin and Nelson 2000). The Howard Hansen Dam on
the Green River effectively prevents delivery of coarse sediment from the upper basin to
downstream reaches, although suspended sediment continues to be carried past the dam (Kerwin
and Nelson 2000).
The majority of the existing mainstem Cedar River habitat has been disconnected from historic
floodplains through the construction of revetments. This, in turn, results in a loss of channel
habitat complexity and a reduction in the supply and stability of spawning gravels (Kerwin 2001).
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) G-4
4679
The project will: Improve Maintain Degrade, or Temporarily degrade this 4680
indicator 4681
4682
Briefly describe how, at both the watershed scale and the project action area scale: 4683
WSDOT will provide flow control for runoff from new and existing impervious areas to address
changes in stormwater discharge to fish bearing streams except for the direct discharge proposed
for the Cedar River. Stormwater flow control facilities will be designed in accordance with the
WSDOT HRM (2006).
New storm drainage systems will collect and treat runoff from an area greater than all new
impervious surfacing created by the Project.
4684
1.3.2 Large Woody Debris: 4685
Briefly describe the current condition of this indicator at both the watershed scale and the 4686
project action area scale: 4687
Large woody debris (LWD) conditions in the Lower Green River Subwatershed and the Lower
Cedar River Subarea are not properly functioning per the NMFS Matrix of Pathways and
Indicators for salmonids and functioning at unacceptable risk per the USFWS Matrix of
Diagnostics/Pathways and Indicators for bull trout.
Ninety-seven percent of the riparian zone in the lower Green River is considered to have poor
LWD recruitment potential and microclimate conditions because native vegetation communities
have largely been converted to grass or shrubs, and because development often extends to within
75 feet of the channel. None of the riparian zone along the lower Green River is considered to
have good LWD recruitment potential (Kerwin and Nelson 2000).
LWD recruitment is currently rated poor along almost 100 percent of the lower Cedar River, and
land use practices generally preclude active recruitment. Large amounts of LWD are removed at
Landsburg Dam due to liability concerns (Kerwin 2001).
Stream surveys conducted for the Project found the streams and rivers in the action area to be
lacking in LWD.
4688
The project will: Improve Maintain Degrade, or Temporarily degrade this 4689
indicator 4690
4691
Briefly describe how, at both the watershed scale and the project action area scale: 4692
No impacts to LWD are anticipated in any waterbody with listed species.
4693
1.3.3 Pool Frequency: 4694
Briefly describe the current condition of this indicator at both the watershed scale and the 4695
project action area scale: 4696
Pool frequency conditions in the Lower Green River Subwatershed and the Lower Cedar River
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) G-5
Subarea are not properly functioning per the NMFS Matrix of Pathways and Indicators for
salmonids and functioning at unacceptable risk per the USFWS Matrix of Diagnostics/Pathways
and Indicators for bull trout.
In the Lower Green River Subwatershed, increased fine sediment delivery from upstream reaches
and urbanized tributaries is filling pools and substrate interstitial spaces, thereby reducing the
amount and quality of habitat available for rearing juvenile salmonids (Kerwin and Nelson 2000).
The majority of the existing mainstem Cedar River habitat has been disconnected from historic
floodplains through the construction of revetments. This, in turn, results in a loss of channel
habitat complexity and a reduction in the supply and stability of spawning gravels (Kerwin 2001).
The project will: Improve Maintain Degrade, or Temporarily degrade this 4697
indicator 4698
4699
Briefly describe how, at both the watershed scale and the project action area scale: 4700
No changes to pool frequency will occur in any waterbodies with listed species.
4701
1.3.4 Pool Quality: 4702
Briefly describe the current condition of this indicator at both the watershed scale and the 4703
project action area scale: 4704
Pool quality conditions in the Lower Green River Subwatershed and the Lower Cedar River
Subarea are not properly functioning per the NMFS Matrix of Pathways and Indicators for
salmonids and functioning at unacceptable risk per the USFWS Matrix of Diagnostics/Pathways
and Indicators for bull trout.
In the Lower Green River Subwatershed, increased fine sediment delivery from upstream reaches
and urbanized tributaries is filling pools and substrate interstitial spaces, thereby reducing the
amount and quality of habitat available for rearing juvenile salmonids (Kerwin and Nelson 2000).
The majority of the existing mainstem Cedar River habitat has been disconnected from historic
floodplains through the construction of revetments. This, in turn, results in a loss of channel
habitat complexity and a reduction in the supply and stability of spawning gravels (Kerwin 2001).
The project will: Improve Maintain Degrade, or Temporarily degrade this 4705
indicator 4706
4707
Briefly describe how, at both the watershed scale and the project action area scale: 4708
No changes to pool quality will occur in any waterbodies with listed species.
4709
1.3.5 Off-Channel Habitat: 4710
Briefly describe the current condition of this indicator at both the watershed scale and the 4711
project action area scale: 4712
Off-channel habitat conditions in the Lower Green River Subwatershed and the Lower Cedar
River Subarea are not properly functioning per the NMFS Matrix of Pathways and Indicators for
salmonids and functioning at unacceptable risk per the USFWS Matrix of Diagnostics/Pathways
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) G-6
and Indicators for bull trout.
In the Lower Green River Subwatershed, alterations in the natural flow regime during Howard
Hansen Dam refill operations may adversely impact spring spawning and incubation success by
disconnecting off-channel habitats. Channelization and confinement of the channel between
levees prevents high flows from accessing the floodplains, reducing groundwater recharge.
Narrow, deeper channels have higher water velocity and bed shear stress, thus, even small flood
events may scour bed materials. At the same time, simplification of the channel, including
elimination of access to off-channel areas, reduces the availability of high flow refugia used by
salmonids to escape the high velocity flows and the stability of spawning gravel (Kerwin and
Nelson 2000).
The majority of the existing mainstem Cedar River habitat has been disconnected from historic
floodplains through the construction of revetments. This, in turn, results in a loss of channel
habitat complexity and a reduction in the supply and stability of spawning gravels (Kerwin 2001).
The amount of available fish habitat in the lower mainstem Cedar River has been reduced by
approximately 56 percent due primarily to water diversion and flood control activities. The loss of
off-channel rearing habitat is particularly severe for juvenile Chinook salmon. Historically, this
habitat would have been utilized by juvenile Chinook salmon for rearing which, in turn, would
have resulted in a larger and later timing out-migrant from the Cedar River. Because of the loss of
this habitat, this life history trajectory has been reduced. This loss of habitat forces juvenile
Chinook salmon to migrate as very young fry into Lake Washington, a life history trajectory which
may not favor their survival (Kerwin 2001).
4713
The project will: Improve Maintain Degrade, or Temporarily degrade this 4714
indicator 4715
4716
Briefly describe how, at both the watershed scale and the project action area scale: 4717
Off-channel habitat conditions are not anticipated to significantly change at either the watershed or
Project action area scale as a result of the Project.
4718
1.3.6 Refugia: 4719
Briefly describe the current condition of this indicator at both the watershed scale and the 4720
project action area scale: 4721
Refugia conditions in the Lower Green River Subwatershed and the Lower Cedar River Subarea
are not properly functioning per the NMFS Matrix of Pathways and Indicators for salmonids and
functioning at unacceptable risk per the USFWS Matrix of Diagnostics/Pathways and Indicators
for bull trout.
Adequate refugia is lacking in the watersheds in the action area; LWD, pool frequency, and off-
channel habitat conditions are all not properly functioning. Existing refugia is fragmented and
insufficient in size to maintain viable populations.
4722
The project will: Improve Maintain Degrade, or Temporarily degrade this 4723
indicator 4724
4725
Briefly describe how, at both the watershed scale and the project action area scale: 4726
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) G-7
No changes to refugia will occur in waterbodies with listed species.
4727
1.4 Channel Conditions and Dynamics 4728
1.4.1 Width/Depth Ratio: 4729
Briefly describe the current condition of this indicator at both the watershed scale and the 4730
project action area scale: 4731
Per information collected in the stream surveys for the Project, width/depth ratio conditions in the
Lower Green River Subwatershed and the Lower Cedar River Subarea are not properly
functioning per the NMFS Matrix of Pathways and Indicators for salmonids and functioning at
unacceptable risk per the USFWS Matrix of Diagnostics/Pathways and Indicators for bull trout.
Width/depth ratio conditions at the watershed level are not well documented, and little information
was found in this regard.
4732
The project will: Improve Maintain Degrade, or Temporarily degrade this 4733
indicator 4734
4735
Briefly describe how, at both the watershed scale and the project action area scale: 4736
Width/depth ratio conditions are not anticipated to significantly change at either the watershed or
project action area scale as a result of the Project.
4737
1.4.2 Streambank Condition: 4738
Briefly describe the current condition of this indicator at both the watershed scale and the 4739
project action area scale: 4740
Streambank conditions in the Lower Green River Subwatershed and the Lower Cedar River
Subarea are not properly functioning per the NMFS Matrix of Pathways and Indicators for
salmonids and functioning at unacceptable risk per the USFWS Matrix of Diagnostics/Pathways
and Indicators for bull trout.
While there are some areas of riparian vegetation that have a width and vegetation type sufficient
to maintain good bank stability, over 80 percent of the banks in the Lower Green River are
comprised of levees or revetments. These structures artificially maintain bank stability and
prevent erosion (Kerwin and Nelson 2000).
Streambank conditions in the Lower Cedar River Subarea are not well documented, and little
information was found in this regard.
The project will: Improve Maintain Degrade, or Temporarily degrade this 4741
indicator 4742
4743
Briefly describe how, at both the watershed scale and the project action area scale: 4744
Streambank conditions are not anticipated to significantly change at either the watershed or Project
action area scale as a result of the Project. Existing streambank armoring will remain in place
throughout the Project area and overall watershed.
4745
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) G-8
1.4.3 Floodplain Connectivity: 4746
Briefly describe the current condition of this indicator at both the watershed scale and the 4747
project action area scale: 4748
Floodplain connectivity conditions in the Lower Green River Subwatershed and the Lower Cedar
River Subarea are not properly functioning per the NMFS Matrix of Pathways and Indicators for
salmonids and functioning at unacceptable risk per the USFWS Matrix of Diagnostics/Pathways
and Indicators for bull trout.
In the Lower Green River Subwatershed, 6 miles of floodplain channel type and 14 miles of
palustrine channel type have been channelized. Both palustrine and floodplain channel types
typically have complex planforms and dissipate flood energy by overbank flows. Consequently,
channelization has presumably resulted in the loss of almost all mainstem winter rearing habitat
and a reduction in the quality of summer rearing and adult holding habitat in these segments
(Kerwin and Nelson 2000). Virtually all of the former palustrine channel between river mile (RM)
11 and RM 25 is currently confined between levees and/or revetments (Fuerstenberg et al. 1996).
The majority of the existing mainstem Cedar River habitat has been disconnected from historic
floodplains through the construction of revetments (Kerwin 2001).
The project will: Improve Maintain Degrade, or Temporarily degrade this 4749
indicator 4750
4751
Briefly describe how, at both the watershed scale and the project action area scale: 4752
Floodplain connectivity conditions are not anticipated to significantly change at either the
watershed or Project action area scale as a result of this Project.
4753
1.5 Flow/Hydrology 4754
1.5.1 Road Density and Location: 4755
Briefly describe the current condition of this indicator at both the watershed scale and the 4756
project action area scale: 4757
Road density and location conditions in the Lower Green River Subwatershed and the Lower
Cedar River Subarea are not properly functioning per the NMFS Matrix of Pathways and
Indicators for salmonids and functioning at unacceptable risk per the USFWS Matrix of
Diagnostics/Pathways and Indicators for bull trout.
Road densities in both watersheds are greater than 3 miles per square mile, with many roads on the
valley floor.
4758
The project will: Improve Maintain Degrade, or Temporarily degrade this 4759
indicator at the watershed scale and Improve Maintain Degrade, or Temporarily 4760
degrade this indicator at the action area scale 4761
4762
Briefly describe how, at both the watershed scale and the project action area scale: 4763
Construction of the Project will result in a net increase of 69.60 acres of impervious surfacing in
the impacted watersheds. This increase in impervious surfacing is very small when compared to
the overall watersheds in which the action area is located.
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) G-9
4764
1.5.2 Disturbance History: 4765
Briefly describe the current condition of this indicator at both the watershed scale and the 4766
project action area scale: 4767
Disturbance history conditions in the Lower Green River Subwatershed and the Lower Cedar
River Subarea are not properly functioning per the NMFS Matrix of Pathways and Indicators for
salmonids and functioning at unacceptable risk per the USFWS Matrix of Diagnostics/Pathways
and Indicators for bull trout.
Both watersheds are highly urban in nature and have a long history of disturbance.
The project will: Improve Maintain Degrade, or Temporarily degrade this 4768
indicator 4769
4770
Briefly describe how, at both the watershed scale and the project action area scale: 4771
Disturbance conditions are not anticipated to significantly change at either the watershed or
Project action area scale as a result of the Project. The areas that will be impacted by the Project
are already in a highly-disturbed state.
4772
1.5.3 Riparian Reserves: 4773
Briefly describe the current condition of this indicator at both the watershed scale and the 4774
project action area scale: 4775
Riparian reserve conditions in the Lower Green River Subwatershed and the Lower Cedar River
Subarea are not properly functioning per the NMFS Matrix of Pathways and Indicators for
salmonids and functioning at unacceptable risk per the USFWS Matrix of Diagnostics/Pathways
and Indicators for bull trout.
Cumulatively, there is less than 1 mile of intact riparian zone comprised of medium to large mixed
deciduous and coniferous trees along the lower mainstem Green River. Approximately 18 percent
(12.4 miles) of the riparian zone in the Lower Green River sub-watershed supports native
deciduous trees. However, in most cases, deciduous stands are narrow (less than 100 feet) or
comprised of small, sparse trees mixed with patches of grass, pavement, or bare ground. Almost
50 percent of the riparian zone is comprised of forbs and grass, or shrubs, many of which are non-
native (Kerwin and Nelson 2000).
Riparian vegetation is severely lacking within this reach of the Cedar River. In many areas along
the Cedar River, development is present to the edge of the dike system. In those places, virtually
no riparian vegetation is present. Where development is set back from the Cedar River, vegetation
consists primarily of non-native invasive plant species including Himalayan blackberry, reed
canarygrass, and Scot's broom, though some native deciduous and coniferous trees and shrubs are
infrequently found along the banks.
The project will: Improve Maintain Degrade, or Temporarily degrade this 4776
indicator 4777
4778
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) G-10
Briefly describe how, at both the watershed scale and the project action area scale: 4779
Riparian reserve conditions are not anticipated to significantly change at either the watershed or
Project action area scale as a result of the Project. The areas that will be impacted by the Project
are already in a highly-disturbed state.
4780
1.6 Pathways and Indicators Specific to Bull Trout Only 4781
1.6.1 Subpopulation Characteristics within Subpopulation Watershed 4782
1.6.1.1 Subpopulation Size 4783
Briefly describe the current condition of this indicator at both the watershed scale and the 4784
project action area scale: 4785
There are no distinct bull trout subpopulations associated with the Lower Green River
Subwatershed and the Lower Cedar River Subarea, although a portion of the action area falls
within the Lake Washington foraging, migration, and overwintering habitat (USFWS 2004). Lake
Washington foraging, migration, and overwintering habitat consists of the lower Cedar River
below Cedar Falls; the Sammamish River; Lakes Washington, Sammamish, and Union; the Lake
Washington Ship Canal; and all accessible tributaries (Mercer Slough and Kelsey Creek are
included in this habitat area). Population status information, extent of use, and complete recovery
value of this area is currently unknown (USFWS 2004). No spawning activity or juvenile rearing
has been observed and no distinct spawning populations are known to exist in Lake Washington
outside of the upper Cedar River above Lake Chester Morse. The potential for spawning in the
Lake Washington Basin is believed to be very low as a majority of accessible habitat is low
elevation, below 152 meters (500 feet), and thus not expected to have the proper thermal regime to
sustain successful spawning (USFWS 2004).
Aside from spawning, the Lake Washington drainage has both potential benefits and challenges to
adult and subadult bull trout. Two large lakes with high forage fish availability are dominant parts
of the lower watershed, and provide significant foraging habitat. A number of observations of
subadult and adult sized bull trout have been made in Lake Washington (USFWS 2004). The
connection with the Chester Morse Lake core area (population located in the upper Cedar River) is
one-way only, and currently the level of connectivity with other core areas is unknown.
Observations of bull trout in the Ballard Locks suggest migrations from other watersheds is likely
occurring (USFWS 2004).
The project will: Improve Maintain Degrade, or Temporarily degrade this 4786
indicator N/A 4787
4788
Briefly describe how, at both the watershed scale and the project action area scale: 4789
The Project will have no effect on bull trout subpopulation size as there is no distinct bull trout
subpopulation associated with the Lower Green River Subwatershed and the Lower Cedar River
Subarea.
4790
1.6.2 Growth and Survival 4791
Briefly describe the current condition of this indicator at both the watershed scale and the 4792
project action area scale: 4793
There are no distinct bull trout subpopulations associated with the Lower Green River
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) G-11
Subwatershed and the Lower Cedar River Subarea.
4794
The project will: Improve Maintain Degrade, or Temporarily degrade this 4795
indicator N/A 4796
4797
Briefly describe how, at both the watershed scale and the project action area scale: 4798
The Project will have no effect on bull trout growth and survival as there are no distinct bull trout
subpopulations associated with the Lower Green River Subwatershed and the Lower Cedar River
Subarea.
4799
1.6.3 Life History Diversity and Isolation: 4800
Briefly describe the current condition of this indicator at both the watershed scale and the 4801
project action area scale: 4802
Life history diversity and isolation conditions are functioning at unacceptable risk per the USFWS
Matrix of Diagnostics/Pathways and Indicators for bull trout. Migratory forms of bull trout are
anticipated to use the Project area, but no bull trout subpopulations are close to the Project area.
Habitat in the Project area has been disrupted and there are numerous fish passage barriers in the
action area barrier to bull trout migrating through the waterbodies of the Project area.
4803
The project will: Improve Maintain Degrade, or Temporarily degrade this 4804
indicator 4805
4806
Briefly describe how, at both the watershed scale and the project action area scale: 4807
Life history diversity and isolation conditions are not anticipated to significantly change at either
the watershed or Project action area scale as a result of the Project.
4808
1.6.4 Persistence and Genetic Integrity: 4809
Briefly describe the current condition of this indicator at both the watershed scale and the 4810
project action area scale: 4811
As mentioned above, there are no distinct bull trout subpopulations associated with the Lower
Green River Subwatershed and the Lower Cedar River Subarea
4812
The project will: Improve Maintain Degrade, or Temporarily degrade this 4813
indicator N/A 4814
4815
Briefly describe how, at both the watershed scale and the project action area scale: 4816
The Project will have no effect on persistence and genetic integrity as there are no distinct bull
trout subpopulations associated with the Lower Green River Subwatershed and the Lower Cedar
River Subarea.
4817
1.6.5 Integration of Species and Habitat Conditions: 4818
Briefly describe the current condition of this indicator at both the watershed scale and the 4819
project action area scale: 4820
There are no distinct bull trout subpopulations associated with the Lower Green River
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) G-12
Subwatershed and the Lower Cedar River Subarea. High stream temperatures, low levels of
dissolved oxygen, and highly disturbed in-water habitat in the waterbodies of the watershed likely
limits bull trout use in this watershed. Stream water temperatures and the presence of pesticides
may limit the natural production of salmonids.
4821
The project will: Improve Maintain Degrade, or Temporarily degrade this 4822
indicator N/A 4823
4824
Briefly describe how, at both the watershed scale and the project action area scale: 4825
Integration of Species and Habitat Conditions are not anticipated to significantly change as a result
of this project.
4826
1.7 References 4827
Fuerstenberg, R.R., K. Nelson, and R. Blomquist. 1996. Ecological conditions and limitations to 4828
salmonid diversity in the Green River, Washington U.S.A. King County Surface Water 4829
Management, Bellevue, WA. 4830
4831
Kerwin, J. 2001. Salmon and Steelhead Habitat Limiting Factors Report for the Cedar – Sammamish 4832
Basin (Water Resource Inventory Area 8). Washington Conservation Commission. Olympia, 4833
WA 4834
4835
Kerwin, John and Nelson, Tom S. (Eds.). 2000. Habitat Limiting Factors and Reconnaissance 4836
Assessment Report, Green/Duwamish and Central Puget Sound Watersheds (WRIA 9 and 4837
Vashon Island). Washington Conservation Commission and the King County Department of 4838
Natural Resources. 4839
4840
U.S. Fish and Wildlife Service (USFWS). 2004. Draft Recovery Plan for the Coastal-Puget Sound 4841
Distinct Population Segment of Bull Trout (Salvelinus confluentus). Volume I (of II): Puget 4842
Sound Management Unit. Portland, Oregon. 389 + xvii pp. 4843
4844
WSDOT. 2006. Highway Runoff Manual M31-16. Olympia, WA. WSDOT Engineering and 4845
Regional Operations Division, Environmental and Engineering Programs, Headquarters 4846
Environmental Affairs and Hydraulics. 4847
4848
WSDOT. 2007. Draft Assessment of Culverts for Fish Passage--Project Areas Involving In-Water 4849
Work. I-405, Tukwila to Renton Improvement Project (I-5 to SR 169 - Phase 2). Prepared by 4850
I-405 Project Team. January, 2007. 4851
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) H-1
Appendix H Tukwila to Renton Improvement Project 4852
ESA Analytical Table 4853
4854
Tukwila to Renton Improvement Project ESA Analytical TableStressorWhen Duration Frequency Life History FormIncreased runoffImplement new flow controlsFinal design will meet HRM requirementsNegligible due to new flow controls TurbidityContractor will be required to meet conditions of Ecology/WSDOT implementing agreementReduced foraging efficiency within mixing zoneStreambank erosionThree years: two years for construction, one for vegetation stabilization Three years: two years for construction, one for vegetation stabilization Reduced foraging/avoidanceReplant riparian and upland areas per revegetation plan requirementsNegligible effects Increased water temperature due to shade reductionReduce foraging efficiency and overwintering/rearing habitatLoss of cover due to loss of overhanging vegetationReduced foraging, increase predation Potential reduced baseflowReduced overwintering/rearing by Chinook and bull troutReduce foraging efficiency and overwintering/rearing habitatReduced benthic abundance and diversity from riparian impact and settling of sediment (covering benthos)Reduced foragingInsignificant due to the nature of the riparian habitat impacted and the prevalence of sediment already in the systemIncreased runoff Implement new flow controls Final design will meet HRM requirementsNegligible due to new flow controls Turbidity Contractor will be required to meet conditions of Ecology/WSDOT implementing agreement Reduced foraging efficiency within mixing zone Streambank erosionThree years: two years for construction, one for vegetation stabilizationThree years: two years for construction, one for vegetation stabilization Reduced foraging/avoidance Replant riparian and upland areas per revegetation plan requirements negligible effects Increased water temperature due to shade reduction Reduce foraging efficiency and overwintering/rearing habitat Loss of cover due to loss of overhanging vegetation Reduced foraging, increase predation Potential reduced baseflow Reduced overwintering/rearing by Chinook and bull trout Reduce foraging efficiency and overwintering/rearing habitatReduced benthic abundance and diversity from riparian impact and settling of sediment (covering benthos)Reduced foragingInsignificant due to the nature of the riparian habitat impacted and the prevalence of sediment already in the systemNonePerformance StandardsResulting Effects of the ActionWhereNone. Clearing will not exceed marked boundaries. Implement TESC. Follow Ecology/WSDOT implementing agreement. Delineate clearing/grading boundaries with construction fencing prior to clearing/grading. Replant bare areas. Delineate clearing/grading boundaries with construction fencing prior to clearing/gradingImplement mitigation and revegetation planIn perpetuity24 hours Response to Stressor Minimization MeasuresDuring rain events throughout construction Adult bull trout, adult and juvenile steelhead, adult and juvenile Chinook salmonDelayed foraging/avoidanceReduced foraging/less time and less use of area for bull trout and steelhead overwintering or Chinook or steelhead rearingExposureIn perpetuityTemporary vegetation impactThroughout project areaDuring rain eventsTen years until vegetation. establishesAction Throughout project areaDuring rain events In perpetuityPermanent vegetation removal and grading Implement revegetation plan24 hours Ten years until vegetation. establishesNine times yearly10 years until vegetation. establishesDelayed foraging/avoidance Reduced foraging/less time and less use of area for bull trout and steelhead overwintering or Chinook or steelhead rearingImplement TESC. Follow Ecology/WSDOT implementing agreement. Delineate clearing/grading boundaries with construction fencing prior to clearing/grading. Replant bare areas. Delineate clearing/grading boundaries with construction fencing prior to clearing/grading None. Clearing will not exceed marked boundariesNoneAdult bull trout, adult and juvenile steelhead, adult and juvenile Chinook salmonBiological Assessment for I-405, Tukwila to Renton Improvement Project (I-5 to SR 169 – Phase 2)
Tukwila to Renton Improvement Project ESA Analytical TableStressorWhen Duration Frequency Life History FormPerformance StandardsResulting Effects of the ActionWhereResponse to Stressor Minimization MeasuresExposureAction Increased turbidity During rain events during construction 24 hours During rain events Delayed foraging/avoidance Implement TESC and SPCC Reduced foraging efficiency within mixing zoneChanges in hyporheic flow due to compaction (potential reduced base flow) Reduced overwintering/rearing None Reduce foraging efficiency and overwintering/rearing habitatHabitat lossDelayed foraging, reduced overwintering/rearing/ foragingProject mitigationLoss of habitat will be offset by mitigationIncreased contaminants (pavement materials and heavy equipment) Reduced foraging, increased predation, displacement Implement TESC and SPCCNo uncured concrete shall come into contact with waters of the state Increased runoff Delayed foraging/avoidance Increased temperature Reduced foraging/less time and less use of area for bull trout overwintering or Chinook rearing Habitat loss In perpetuity In perpetuity In perpetuityDelayed foraging and reduced overwintering/rearing/ foragingProject mitigationLoss of habitat will be offset by mitigationIncreased turbidity Delayed foraging/avoidanceImplement TESC and SPCC. Existing roads will be used whenever reasonable. The number of stream crossings will be minimized. Contractor will be required to meet conditions ofReduced foraging efficiency Increased contaminants (heavy equipment) Reduced foraging, increased predation, displacementExisting roads will be used whenever reasonable. The number of stream crossings will be minimized. Implement TESC and SPCC plan InsignificantIncreased turbidity Delayed foraging/avoidance Increased contaminants (heavy equipment) Reduced foraging, increased predation, displacementNot measurableNoneConstruct retaining wallsThroughout project areaDuring rain events during construction24 hoursDuring rain events throughout construction Adult bull trout, adult and juvenile steelhead, adult and juvenile Chinook salmonImplement TESC and SPCC; Contractor will be required to meet conditions of Ecology/WSDOT implementing agreementAdult bull trout, adult and juvenile steelhead, adult and juvenile Chinook salmon24 hoursDuring rain events throughout construction Construct new impervious surface for roadwayThroughout project areaPlace fill for new roadwayThroughout project areaIn perpetuity In perpetuity In perpetuityAdult bull trout, adult and juvenile steelhead, adult and juvenile Chinook salmonNoneDuring rain events Constructing temporary access roadsThroughout project areaDuring rain events during construction24 hours During rain events Adult bull trout, adult and juvenile steelhead, adult and juvenile Chinook salmonNoneImplement flow control and water quality featuresNoneMinimization measures are expected to reduce effects on fish to insignificant levels.Biological Assessment for I-405, Tukwila to Renton Improvement Project (I-5 to SR 169 – Phase 2)
Tukwila to Renton Improvement Project ESA Analytical TableStressorWhen Duration Frequency Life History FormPerformance StandardsResulting Effects of the ActionWhereResponse to Stressor Minimization MeasuresExposureAction Increased turbidity Delayed foraging/avoidance. Increased contaminants (heavy equipment) Reduced foraging, increased predation, displacement Habitat loss In perpetuity for habitat loss Habitat lossIncreased temperature Reduced cover Reduced productivity Reduced foraging In-water disturbanceDuring In water work window - July 15-August 31 Duration of stormwater outfallsDuring outfall constructionAvoidance, delayed or reduced feeding efficiency, delayed migrationHarassmentIncreased turbidity Delayed foraging/avoidance Increased contaminants (heavy equipment) Reduced foraging, increased predation, displacementElevated turbidity During storm events 24 hours During storm events Delayed foraging/avoidance, injury, delayed migrationDuring demolition, materials shall not be stored where upland runoff can cause the materials or leachate to enter into surface waters, implement TESC and SPCC, Contractor will be required to meet conditions of Reduced foraging efficiency within mixing zoneContaminants from bridge paint, sawcutting, and equipment operation InjurySPCC and NPDES requirements; All debris will be contained Minimization measures expected to reduce effects to insignificant levelNoise DisturbanceConstruct temporary and permanent stormwater and erosion control BMPs, also new outfalls and/or outfall relocations, implement SPCC, grading Throughout project areaDuring rain events during constructionIn perpetuity (permanent BMPs) 24 hours In perpetuity (permanent BMPs) During construction In perpetuity Adult bull trout, adult and juvenile steelhead, adult and juvenile Chinook salmonReduced foraging/less time and less use of area for bull trout overwintering or Chinook rearing To the extent possible, existing drainage infrastructure will be utilized. Peak flows are anticipated to have only negligible effects on waterbodies. Implement TESC and SPCC. Limit construction footprint in environmentally sensitive areas to minimum necessary to construct project. Contractor will be required to meet conditions of Ecology/WSDOT implementing agreementNoneMinimization measures are expected to reduce effects on fish to insignificant levelsMinimization measures are expected to reduce effects on fish to insignificant levelsEstablish and utilize staging and stock pile areas Throughout project areaDuring rain events during construction24 hoursDuring rain events during construction Adult bull trout, adult and juvenile steelhead, adult and juvenile Chinook salmonImplement SPCC and TESCStaging and or material stock pile areas will not be located within 150 feet of any streams, rivers, or wetlands unless in an already developed areaMinimization measures are expected to reduce effects on fish to insignificant levels.Remove existing bridges, including piers and abutments (for those within OHWM) Green River and Cedar River In-water work window: July 15-August 31 (and time outside of window for work over and adjacent to water- spring and early summer) Duration of demolition Daily during demolitionAdult bull trout, adult and juvenile steelhead, adult and juvenile Chinook salmonAvoidance, delayed or reduced feeding opportunityOnly operate during daylight hours; work area will not be lit at night or lighting will not be directed at the water. NoneAvoidance; reduced foraging efficiencyBiological Assessment for I-405, Tukwila to Renton Improvement Project (I-5 to SR 169 – Phase 2)
Tukwila to Renton Improvement Project ESA Analytical TableStressorWhen Duration Frequency Life History FormPerformance StandardsResulting Effects of the ActionWhereResponse to Stressor Minimization MeasuresExposureAction Turbidity Day and nightDelayed foraging/avoidance, injury, delayed migration Implement TESC and implementing agreement between Ecology and WSDOT Reduced foraging efficiency within mixing zone Contaminants (heavy equipment) Reduced foraging, increased predation, displacement Implement SPCCMinimization measures expected to reduce effects to insignificant level Noise Injury and avoidance Avoidance; reduced foraging efficiency; delayed migration Disturbance AvoidanceAvoidance; reduced foraging efficiency Loss of benthic habitat and benthos speciesDuration of cofferdam placement Day and night Reduced foraging efficiency None Reduced foraging efficiencyElevated turbidity Elevated contaminants (waste water and heavy equipment)Handling Injury and elevated stress ElectrofishingInjury or mortalityIncreased turbidity Debris accumulation on bridges and within bridge drains shall be collected and properly disposed of off site; Contractor will be required to meet conditions of Ecology/WSDOT implementing agreementIncreased contaminants (heavy equipment) Implement SPCC Increased shading In perpetuity In perpetuity In perpetuityIncreased predation on juvenile fishNoneEffects to listed fish are expected to be insignificantElevated sound pressure levels In water work window -July 15-August 31 During pile installation During installations Avoidance, injury, mortality Implement pile driving minimization measures Avoidance, reduced foraging efficiency, delayed migration Habitat displacement and potential loss of invertebrate production Increased shading Change in habitat forming processes Contaminants (from piles and heavy equipment)During rain events while structures are in placeDuring of rain events During rain events Injury Implement SPCC NoneConstruction of dewatered work area for new piers Green RiverIn water work window -July 15-August 31 In-water work period plus one dayIn-water work period during daylight hours Daylight hours unless otherwise specified through the permitting processAdult bull trout, adult and juvenile steelhead, adult and juvenile Chinook salmonMinimize size of cofferdamsNoneDispose of waste waterThroughout project areaIn water work window -July 15-August 31 Throughout constructionDay and nightAdult bull trout; adult and juvenile steelhead, adult and juvenile Chinook salmonInjury, avoidance, delayed or reduced feeding opportunity, delayed migration.Contain waste water and dispose of in an upland location where it will not enter surface watersNoneMinimization measures expected to reduce effects to insignificant levelHandle fish Green River, Panther Creek, Gilliam Creek, Cedar RiverIn water work window -July 15-August 31 Unspecified, but during in-water work windowUnknownAdult bull trout, adult and juvenile steelhead, adult and juvenile Chinook salmonFollow latest version of WSDOT's fish handling protocolNoneFish within the area of effect could be injured, harassed, and killedDuring rain events 24 hours During rain events Injury, avoidance, delayed or reduced feeding opportunity, delayed migrationMinimization measures expected to reduce effects to insignificant level Reconstruction or widening permanent bridges over waterCedar River, Green RiverAdult bull trout, adult and juvenile steelhead, adult and juvenile Chinook salmonNoneInstall piles for permanent and temporary work bridges Green RiverYear-round In perpetuity In perpetuityAdult bull trout, adult and juvenile steelhead, adult and juvenile Chinook salmonReduced foraging efficiency; reduced productivity; increased predationLimit size of structures to the minimum necessary NoneReduced productivity, reduced foraging efficiency, increased predationBiological Assessment for I-405, Tukwila to Renton Improvement Project (I-5 to SR 169 – Phase 2)
Tukwila to Renton Improvement Project ESA Analytical TableStressorWhen Duration Frequency Life History FormPerformance StandardsResulting Effects of the ActionWhereResponse to Stressor Minimization MeasuresExposureAction Turbidity Delayed foraging/avoidance, injury, delayed migration During demolition, materials shall not be stored where upland runoff can cause the materials or leachate to enter into surface waters, a containment boom will be used to contain and collect any floating debris and sheen; Contractor will be required to meet conditions of Ecology/WSDOT implementing agreementReduced foraging efficiency within mixing zone Contaminants (heavy equipment, bridge materials) Reduced foraging, increased predation, displacement Implement SPCCMinimization measures expected to reduce effects to insignificant level Noise Injury and avoidance Avoidance; reduced foraging efficiency; delayed migration DisturbanceAvoidanceAvoidance; reduced foraging efficiencyElevated turbidity Injury, avoidance, delayed or reduced feeding opportunity, delayed migration Contaminants (heavy equipment) Injury DisturbanceAvoidance NoneAvoidance; reduced foraging efficiencyTurbidity Day and nightInjury, avoidance, delayed or reduced feeding opportunity Removed water would be pumped into tanks or upland area; Contractor will be required to meet conditions of Ecology/WSDOT implementing agreementContaminants (heavy equipment) Injury Implement SPCC Noise Injury and avoidance Disturbance Avoidance Loss of benthic habitat and benthos speciesDuration of dewatered areaDay and nightReduced foraging opportunityMinimize size of work area.Remove temporary work bridges Green RiverIn water work window -July 15-August 31 During pile removal Daylight hoursAdult bull trout, adult and juvenile steelhead, adult and juvenile Chinook salmonNoneNoneConstruct temporary diversion dams for dewatering work areasGreen River, Panther Creek, Gilliam Creek, Cedar RiverIn water work window -July 15-August 31 UnknownPer WSDOT fish removal proceduresDaylight hoursAdult bull trout; adult and juvenile steelhead, adult and juvenile Chinook salmonDam installation will either be by hand or by equipment operated from the banks, overhead bridges or outside the wetted perimeter. Material placed within the water will be free of sediment and other contaminants NoneMinimization measures expected to reduce effects to insignificant levelMinimization measures expected to reduce effects to insignificant level Dewater work area Green River, Panther Creek, Gilliam Creek, Cedar RiverIn water work window -July 15-August 31 In-water work window In-water work period during daylight hours Daylight hoursAdult bull trout, adult and juvenile steelhead, adult and juvenile Chinook salmonNone Biological Assessment for I-405, Tukwila to Renton Improvement Project (I-5 to SR 169 – Phase 2)
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) I-1
Appendix I Biology of Listed Species 4856
4857
1. Biology of Listed Species 4858
1.1 Terrestrial Species 4859
1.1.1 Bald Eagle 4860
Name of Species: Bald eagle (Haliaeetus leucocephalus) 4861
4862
Evolutionarily Significant Unit (ESU) or Distinct Population Segment (DPS), if applicable: N/A 4863
4864
1.1.1.1 Habitat Requirements and Ecology 4865
Nesting 4866
Nesting occurs from January 1 to August 15 (USFWS 1986). Abundant food is critical during nesting 4867
because young bald eagles are less tolerant to food deprivation than adults. Bald eagle nests are 4868
frequently associated with water, such as the Puget Sound, and most often occur close to shorelines. 4869
4870
The Pacific States Bald Eagle Recovery Plan (USFWS 1986) recommends limiting construction 4871
activities near bald eagle nests during critical wintering and nesting periods. The plan recommends 4872
construction and disturbance setbacks of 400 meters (1,313 feet) if the nest does not have a line of 4873
sight to the proposed construction activity, or 800 meters (2,625 feet) if the nest is within line of sight 4874
of construction. The nearest eagle nest is approximately 2.1 miles from the Project area and 1.6 miles 4875
from the 1 mile action area boundary. The eagle’s territory extends no closer than 1.8 miles to the 4876
Project area. 4877
4878
Foraging 4879
Foraging habitat for bald eagles is typically associated with water features such as rivers, lakes, and 4880
coastal shorelines where fish, waterfowl, and seabirds are preyed upon. Bald eagle foraging is 4881
opportunistic and they feed on dead or weakened prey. Their diets include fish such as salmon, catfish, 4882
pollock, cod, rockfish, carp, dogfish, sculpin, and hake. They also feed on marine birds and their 4883
offspring, and small terrestrial mammals. They prefer high structures for perching such as trees along 4884
the shoreline, but will also use other structures such as cliffs, pilings, and open ground. They are 4885
usually seen foraging in open areas with wide views (Stalmaster and Newman 1979). 4886
4887
The Lake Washington shoreline, especially on Mercer Island across the water from the Project area, 4888
provides good foraging habitat. Piling in the lake, both abandoned and part of actively used structures, 4889
furnish above-water perches in many places along the shoreline. The developed area close to the 4890
highway is of lower quality, supporting few prey mammals and lacking in suitable perching 4891
viewpoints. 4892
4893
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) I-2
Perching 4894
Perch sites may be used for activities including hunting, prey consumption, signaling territory 4895
occupation, and resting. Perches are most often associated with food sources near water and will have 4896
visual access to adjacent habitats (Stalmaster and Newman 1979). Bald eagles will often choose the 4897
highest tree on the edge of a stand, selecting the strongest lateral branches. Migrating eagles could fly 4898
over the site, but are unlikely to forage or perch there due to the lack of suitable perching trees and the 4899
limited prey availability. 4900
4901
Wintering 4902
Wintering activities for bald eagles occur from October 31 through March 31. During the winter 4903
months, bald eagles forage, construct nests, and engage in courtship activities. There may also be bald 4904
eagles from outside the region that forage along the coastline of Puget Sound in the winter. Winter is a 4905
high-stress period for bald eagles because food is scarce and adverse weather requires the birds to 4906
expend more energy to survive. There is no known bald eagle wintering habitat in the Project action 4907
area. The nearest eagle territory does not extend to the Project action area boundary. 4908
4909
1.2 Aquatic Species 4910
1.2.1 Puget Sound Chinook salmon 4911
Name of Species: Puget Sound Chinook salmon (Oncorhynchus tshawytscha) 4912
4913
1.2.1.1 Habitat Requirements and Ecology/Designated Critical Habitat 4914
Habitat requirements for Chinook salmon are listed by the National Marine Fisheries Service (NMFS) 4915
in terms of primary constituent elements (PCEs). PCEs include sites that are essential to supporting 4916
one or more life stages of the ESU and which contain physical or biological features essential to the 4917
conservation of the ESU. Specific sites and features designated for Puget Sound Chinook salmon 4918
include the following: 4919
1. Freshwater spawning sites with water quantity and quality conditions and substrate supporting 4920
spawning incubation and larval development. 4921
2. Freshwater rearing sites with water quantity and floodplain connectivity to form and maintain 4922
physical habitat conditions and support juvenile growth and mobility; water quality and forage 4923
supporting juvenile development; and natural cover such as shade, submerged and overhanging 4924
large wood, log jams and beaver dams, aquatic vegetation, large rocks and boulders, side 4925
channels, and undercut banks. 4926
3. Freshwater migration corridors free of obstruction with water quantity and quality conditions 4927
and natural cover such as submerged and overhanging large wood, aquatic vegetation, large 4928
rocks and boulders, side channels, and undercut banks supporting juvenile and adult mobility 4929
and survival. 4930
4. Estuarine areas free of obstruction with water quality, water quantity, and salinity conditions 4931
supporting juvenile and adult physiological transitions between fresh- and saltwater; natural 4932
cover such as submerged and overhanging large wood, aquatic vegetation, large rocks and 4933
boulders, and side channels; and juvenile and adult forage, including aquatic invertebrates and 4934
fishes, supporting growth and maturation. 4935
5. Nearshore marine areas free of obstruction with water quality and quantity conditions and 4936
forage, including aquatic invertebrates and fishes, supporting growth and maturation; and 4937
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) I-3
natural cover such as submerged and overhanging large wood, aquatic vegetation, large rocks 4938
and boulders, and side channels. 4939
6. Offshore marine areas with water quality conditions and forage, including aquatic invertebrates 4940
and fishes supporting growth and maturation. 4941
4942
Puget Sound Chinook salmon are anadromous (spawning in freshwater and migrating to marine waters 4943
to mature) and semelparous (spawning once, then dying). Adult females spawn in gravel beds (called 4944
redds) with suitable gravel size, water depth, and velocity. The female guards the redd for 4 to 25 days 4945
before dying (NOAA Fisheries 2004). 4946
4947
Chinook salmon exhibit great variability with respect to the duration and types of habitats used for 4948
rearing. Juveniles can spend several days to a year in freshwater prior to migrating to the estuary 4949
(Healey 1991). This variability can occur within a single stock, but more typically, stocks are 4950
classified as “ocean type” or “stream type.” Ocean type salmon stay in freshwater only briefly (from a 4951
few days to several months) and spend a greater amount of time feeding in estuaries than spring type 4952
Chinook salmon. Stream type salmon can spend 1 to 2 years in freshwater as juveniles, and migrate 4953
rapidly to marine waters. Ocean type salmon are more common in Puget Sound. 4954
4955
Chinook salmon generally require habitat diversity within a single stream for their spawning, rearing, 4956
and foraging activities. They also require cover for protection from predators. Riprap revetments 4957
provide the least suitable habitat for Chinook salmon (ISPG 2002). In small streams, undercut banks 4958
with slower water velocities are often used for rearing habitat. In larger rivers, nearshore areas of 4959
lower water velocity, such as scour pools associated with logs and roots, serve as rearing habitat. 4960
Foraging is done in faster waters, but access to lower-velocity areas, such as eddies behind boulders, 4961
are important “holding” areas where the salmon can expend less energy while waiting for prey to 4962
appear in the faster water (ISPG 2002). Salmonids are closely associated with woody debris, which 4963
offers cover from predators (ISPG 2002). 4964
4965
Chinook salmon use the Green and Cedar Rivers and Springbrook Creek for spawning, rearing, 4966
migration, and foraging. Chinook salmon also likely use Gilliam and Panther reeks for rearing and 4967
foraging. 4968
4969
Life history stages of Chinook salmon that occur in the Green River in the action area are limited to fry 4970
using the Green River for rearing or foraging, and returning adults that would pass through the action 4971
area during upstream spawning migration. The Green River in the action area does not contain any 4972
known spawning habitat. 4973
4974
Life history stages of Chinook salmon that occur in the Cedar River in the action area include adult 4975
spawner, fry, alevin, and egg stages. Chinook salmon also use the Cedar River for foraging. The 4976
reach of the Cedar River in the action area is a known Chinook spawning area. 4977
4978
Life history stages of Chinook salmon that occur in Springbrook Creek in the action area are limited to 4979
fry using Springbrook Creek for rearing or foraging, and returning adults that would pass through the 4980
action area during upstream spawning migration. Springbrook Creek in the action area does not 4981
contain any known spawning habitat. 4982
4983
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) I-4
Chinook salmon use is not documented in Gilliam Creek. However, due to its association with the 4984
Green River, life history stages of Chinook salmon that could occur in Gilliam Creek in the action area 4985
are likely limited to fry that would use Gilliam Creek as an “off-channel” rearing or foraging area. 4986
4987
Chinook salmon use is not documented in Panther Creek; however, Chinook salmon are presumed to 4988
be present in portions of Panther Creek due to its association with Springbrook Creek. Chinook 4989
salmon are not presumed to be present in the west fork of Panther Creek due to a reed canarygrass 4990
wetland that acts as a fish passage barrier. 4991
4992
1.2.2 Bull trout 4993
Name of Species: Bull trout (Salvelinus confluentus) 4994
4995
1.2.2.1 Habitat Requirements and Ecology 4996
Habitat requirements for bull trout are listed by the U.S. Fish and Wildlife Service (USFWS) in terms 4997
of functions and PCEs. Bull trout require the following habitat functions: 4998
1. Spawning, rearing, foraging, or over-wintering habitat to support essential existing local 4999
populations. 5000
2. Movement corridors necessary for maintaining essential migratory life history forms. 5001
3. Suitable habitat that is considered essential for recovering existing local populations that have 5002
declined or that need to be re-established to achieve recovery. 5003
5004
These functions are provided by areas containing these PCEs: 5005
1. Water temperatures ranging from 36 to 59 °F (2 to 15 °C), with adequate thermal refugia 5006
available for temperatures at the upper end of this range. Specific temperatures within this range 5007
will vary depending on bull trout life history stage and form, geography, elevation, diurnal and 5008
seasonal variation, shade such as that provided by riparian habitat, and local groundwater 5009
influence. 5010
2. Complex stream channels with features such as woody debris, side channels, pools, and 5011
undercut banks to provide a variety of depths, velocities, and in-stream structures. 5012
3. Substrates of sufficient amount, size, and composition to ensure success of egg and embryo 5013
overwinter survival, fry emergence, and young-of-the-year and juvenile survival. A minimal 5014
amount of fine substrate less than 0.25 inch (0.63 centimeter) in diameter and minimal substrate 5015
embeddedness are characteristic of these conditions. 5016
4. A natural hydrograph, including peak, high, low, and base flows within historic ranges or, if 5017
regulated, a hydrograph that demonstrates the ability to support bull trout populations by 5018
minimizing daily and day-to-day fluctuations and minimizing departures from the natural cycle 5019
of flow levels corresponding with seasonal variation. 5020
5. Springs, seeps, groundwater sources, and subsurface water connectivity to contribute to water 5021
quality and quantity. 5022
6. Migratory corridors with minimal physical, biological, or water quality impediments between 5023
spawning, rearing, overwintering, and foraging habitats, including intermittent or seasonal 5024
barriers induced by high water temperatures or low flows. 5025
7. An abundant food base including terrestrial organisms of riparian origin, aquatic 5026
macroinvertebrates, and forage fish. 5027
8. Few or no nonnative predatory, interbreeding, or competitive species present. 5028
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) I-5
9. Permanent water of sufficient quantity and quality such that normal reproduction, growth, and 5029
survival are not inhibited. 5030
5031
Very few of these PCEs occur in the action area. 5032
5033
Bull trout are members of the char subgroup of the salmon family. The anadromous type inhabits 5034
upper tributary streams and lake and reservoir systems. Bull trout feed on terrestrial and aquatic 5035
insects, and as they grow in size, their diets include whitefish, sculpins, and other trout. Bull trout 5036
spawn from August through November when they reach maturity, between 4 and 7 years, and when 5037
temperatures begin to drop, in cold, clear streams. Bull trout can spawn repeatedly, and can live over 5038
20 years. Adults and juveniles return to the marine environment between May and early July. 5039
Resident forms of bull trout spend their entire lives in freshwater, while anadromous forms live in 5040
tributary streams for 2 or 3 years before migrating to estuaries as smolts. Char species are generally 5041
longer-lived than salmon; bull trout up to 12 years old have been identified in Washington (Brown 5042
1992). 5043
5044
Bull trout habitat requirements are similar to those of Chinook and coho salmon, but they need slightly 5045
colder water temperatures for successful spawning (ISPG 2002). 5046
5047
Adult bull trout are the only life history stage likely to occur in the action area. The Lake Washington 5048
system has been identified as containing important foraging, migration, and overwintering habitat 5049
necessary for bull trout recovery, but no known bull trout spawning occurs in Lake Washington and 5050
the bull trout found there are likely from the Snohomish-Skykomish and Stillaguamish River systems 5051
(69 Fed Reg 35795). 5052
5053
1.2.3 Puget Sound steelhead 5054
Name of Species: Puget Sound steelhead (Oncorhynchus mykiss) 5055
5056
1.2.3.1 Habitat Requirements and Ecology 5057
The Puget Sound steelhead DPS is listed as threatened. On March 29, 2006, NMFS proposed to list 5058
the Puget Sound steelhead DPS as threatened under the Endangered Species Act (ESA) (71 Federal 5059
Register 15666). NMFS concluded in the proposal (71 Federal Register 15666) that critical habitat 5060
cannot be determined at this time for the Puget Sound steelhead DPS. 5061
5062
Steelhead have the most complex life history traits of any of the anadromous salmonids. Steelhead 5063
may spend anywhere from 1 to 4 years in freshwater (typically 2 to 3 years) and migrate to saltwater 5064
for another 1 to 6 years (typically 2 to 3 years). Puget Sound steelhead are most abundant in Northern 5065
Puget Sound and there are several rivers with summer and winter steelhead stocks. Puget Sound 5066
steelhead exhibit two life history types (winter run and summer run) that are defined based on the 5067
timing of adult returns to their natal spawning streams and by their degree of sexual development at the 5068
time they enter freshwater (NMFS 2005). 5069
5070
In contrast to other species of Pacific salmonids, some steelhead do not die after spawning and are 5071
capable of repeat spawning. Only a small percentage of steelhead (an average of 8 percent overall 5072
among West Coast populations [Busby et al. 1996]) return to the spawning grounds for more than 1 5073
year. Those steelhead that survive after spawning (mostly females) will outmigrate to the marine 5074
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) I-6
environment. These fish are capable of moving offshore in marine waters very soon after migrating 5075
from the river. Repeat spawners may return after 1 or 2 more years at sea. 5076
5077
Generally, juvenile steelhead outmigrate from freshwater between mid-March and early June. Juvenile 5078
steelhead enter marine waters at a much larger size and have a higher rate of survival than other 5079
salmonid species. The majority of steelhead smolts appear to migrate directly to the open ocean and 5080
do not rear extensively in the estuarine or coastal environments (Burgner et al. 1992). 5081
5082
Summer and winter steelhead are known to occur in the Green River. Winter steelhead are known to 5083
occur and spawn in the Cedar River, but no data exist on the presence of summer steelhead. Winter 5084
steelhead are known to occur in the Black River and are presumed to occur in Springbrook Creek. No 5085
data exist on the presence of winter steelhead in Springbrook Creek. No data exist on the presence of 5086
summer or winter steelhead in Gilliam and Panther Creeks. 5087
5088
Winter steelhead are known to use the Green River for spawning, rearing, migration, and foraging. 5089
Spawning occurs in April and May. Winter steelhead have been documented in the Cedar River, 5090
though spawning has not been observed. Steelhead may use portions of Springbrook Creek for rearing 5091
and foraging. Resident steelhead may be present in the Green and Cedar River systems. Because 5092
steelhead are so variable in their length of freshwater and marine residence, it is difficult to predict 5093
which life stages may be present at different times of year. 5094
5095
Various life stages of steelhead could be found in the waterbodies located in the action area at any time 5096
of year, and steelhead are very likely to be in the area in late spring. Steelhead exhibit a wide variety 5097
of residence times in freshwater and saltwater, and it is difficult to predict whether or not they will 5098
occur at other times of the year. 5099
5100
Green River 5101
Summer and winter steelhead are known to use the Green River. Resident forms may also occur. 5102
Steelhead presence is documented in the Green River, but no known spawning or rearing is 5103
documented in the action area. Because migration time is highly variable and steelhead can spawn 5104
more than once, juveniles and adults may occur at any time of year. 5105
5106
Cedar River 5107
Winter-run steelhead are known to rear in the Cedar River within the action area, but no known 5108
spawning is documented. Summer-run and resident forms are not documented, but may occur. 5109
5110
Springbrook Creek 5111
Steelhead spawning does not occur in Springbrook Creek. While no steelhead use is documented, it is 5112
possible that resident and/or anadromous steelhead use Springbrook Creek as a rearing and foraging 5113
area. 5114
5115
Gilliam Creek 5116
Steelhead use is not documented in Gilliam Creek. However, due to its association with the Green 5117
River, life history stages of steelhead that could occur in Gilliam Creek in the action area are likely 5118
limited to fry that would use Gilliam Creek as an off-channel rearing or foraging area. 5119
5120
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) I-7
Panther Creek 5121
Steelhead use is not documented in Panther Creek; however, it is possible that resident and/or 5122
anadromous steelhead use Panther Creek as a rearing and foraging area. Steelhead are not presumed to 5123
be present in the west fork of Panther Creek. 5124
5125
1.3 References 5126
Brown, L. G. 1992. Draft management guide for the bull trout Salvelinus confluentus (Suckley) on 5127
the Wenatchee National Forest. Washington Department of Wildlife, Wenatchee, Washington. 5128
75 pp. 5129
5130
Burgner, R.L., J.T. Light, L. Margolis, T. Okazaki, A. Tautz, and S. Ito. 1992. Distribution and 5131
origins of steelhead trout (Oncorhynchus mykiss) in offshore waters of the North Pacific 5132
Ocean. International North Pacific Fisheries Commission, Bulletin 51. 91 pp. 5133
5134
Busby, P.J., T.C. Wainwright, G.J. Bryant, L.J. Lierheimer, R.S. Waples, F.W. Waknitz, and I.V. 5135
Lagomarsino. 1996. Status review of west coast steelhead from Washington, Idaho, Oregon, 5136
and California. U.S. Dept. Commerce, NOAA Tech. Memo. NMFS –NWFSC-27. 261 pp. 5137
5138
Healey, M.C. 1991. Life history of chinook salmon (Oncorhynchus tshawytscha). Pages 311-393 in 5139
C. Groot and L. Margolis (eds) Pacific Salmon Life Histories. University of British Columbia 5140
Press, Vancouver, British Columbia. 5141
5142
Integrated Streambank Protection Guidelines (ISPG). 2002. Washington State Aquatic Habitat 5143
Guidelines Program. A joint program comprising Washington Department of Fish and 5144
Wildlife, Washington Dept. of Ecology, and Washington State Dept. of Transportation. 5145
5146
Kerwin, J. 2001. Salmon and Steelhead Habitat Limiting Factors Report for the Cedar – Sammamish 5147
Basin (Water Resource Inventory Area 8). Washington Conservation Commission. Olympia, 5148
WA 5149
5150
Kerwin, John and Nelson, Tom S. (Eds.). 2000. Habitat Limiting Factors and Reconnaissance 5151
Assessment Report, Green/Duwamish and Central Puget Sound Watersheds (WRIA 9 and 5152
Vashon Island). Washington Conservation Commission and the King County Department of 5153
Natural Resources. 5154
5155
King County Department of Public Works. 1993. Cedar River Current and Future Conditions Report. 5156
King County Department of Public Works, Surface Water Management Division, Seattle. 5157
5158
Koellmann, Derek and Bryan Patterson. 2005. Anchor Environmental, L.L.C. Personal observations 5159
during I-405 Renton Nickel Improvement Project Stream Surveys, April-June, 2005. 5160
5161
National Oceanic and Atmospheric Administration (NOAA) Fisheries. 2004. Office of Protected 5162
Resources. Chinook Salmon (Oncorhynchus tshawytscha). 5163
http://www.nmfs.noaa.gov/prot_res/species/fish/Chinook_salmon.html 5164
5165
Biological Assessment for I-405, Tukwila to Renton
Improvement Project (I-5 to SR 169 – Phase 2) I-8
National Marine Fisheries Service (NMFS). 2005. Status review update for Puget Sound Steelhead. 5166
Prepared by the 2005 Puget Sound Steelhead Biological Review Team, National Marine 5167
Fisheries Service, Northwest Fisheries Science Center. July 26, 2005. 112 pp 5168
5169
Stalmaster, M.V. and J.R. Newman. 1979. Perch-site preferences of wintering bald eagles in 5170
northwest Washington. Journal of Wildlife Management. 43:221-224. 5171
5172
U.S. Fish and Wildlife Service (USFWS). 1986. Recovery plan for the Pacific bald eagle. U.S. Fish 5173
and Wildlife Service, Portland, Oregon. 160 pp. 5174
5175
5176