HomeMy WebLinkAbout12_Biological_Assessment_2015BIOLOGICAL ASSESSMENT UPDATE
I-405/SR 167 Direct Connector Project
Renton, WA
WIN # 1405504C
Prepared by:
Northwest Region Design Build Project Office
May 2015
EXECUTIVE SUMMARY
The I-405 Tukwila to Renton Improvement Project (Project) is a Washington
State Department of Transportation (WSDOT) project that utilized multiple
construction stages and smaller projects to provide improvements to the
Interstate-405 (I-405) and State Route 167 (SR 167) corridors in and around the
cities of Renton and Tukwila, Washington. All elements of the project were
subject to ESA consultation which concluded with a Biological Opinion issued
jointly by the National Marine Fisheries Service (NMFS) and the U.S. Fish and
Wildlife Service (USFWS) on March 3rd, 2008 (NMFS Tracking No: 2007/04219,
USFWS Log No: 13410-2007-F-0416). Since that time, the I-405, SR 515
Interchange Project, a portion of the overall project, was constructed between
2008 and 2011, as described in the original BA. An additional portion of the
project, the I-405, SR 167 High Occupancy Vehicle Direct Connect Ramp
Project, was included in the consultation, but never funded for construction. As
of 2015 that project, now referred to as the Direct Connector Project, is yet
unfunded for construction, but NEPA has been re-evaluated and a permit
application has been prepared for all federal, state, and local permits needed for
construction. The re-evaluation process revealed that there are new listings
under ESA that were not addressed in the original consultation.
This Biological Assessment Update provides the most current Direct Connector
Project information to determine the effect on yellow-billed cuckoo (Coccyzus
americanus) and the Oregon spotted frog (Rana pretiosa). The BA Update will
also address potential project effects to proposed Puget Sound Steelhead
Critical Habitat, and provide a provisional effect determination, as critical habitat
is expected to be designated in 2015.
This BA Update does not address the streaked horned lark (Eremophila
alpestris strigata) or the Taylor’s checkerspot butterfly (Euphydryas editha
taylori), both listed in 2013. They are not documented or known to occur within
the project action area, and suitable habitat is not present.
The Effect Determinations from the Direct Connector Project on listed species
and proposed critical habitat are as follows:
I-405/SR 167 Direct Connector Project Page i
Table 1. ESA-Listed Species and Effects Determinations
Species Status Agency
Effect
Determination
Critical
Habitat Effect Determination
Yellow-billed
cuckoo
(Coccyzus
americanus)
Threatened USFWS
May effect,
not likely to
adversely
affect
None
designated
in
Washington
State
N/A
Puget Sound
DPS
Steelhead trout
(Oncorhynchus
mykiss)
Threatened NMFS
May effect,
likely to
adversely
affect
(unchanged
from original
consultation)
Proposed
Will not destroy or
adversely
modify.(Provisional)
No Effect
Oregon spotted
frog
(Rana pretiosa)
Threatened USFWS
No Effect Proposed
N/A (no critical
habitat proposed in
King County)
I-405/SR 167 Direct Connector Project Page i
TABLE OF CONTENTS
EXECUTIVE SUMMARY .................................................................................................i
TABLE OF CONTENTS .................................................................................................ii
LIST OF TABLES ...........................................................................................................iii
LIST OF FIGURES .........................................................................................................iii
INTRODUCTION .............................................................................................................. 1
Background and Consultation History ...................................................................... 1
PROJECT DESCRIPTION ............................................................................................. 1
Project Overview .......................................................................................................... 1
Stormwater .................................................................................................................... 4
Fish Passage ................................................................................................................ 5
Road Construction ....................................................................................................... 7
Project Schedule .......................................................................................................... 7
PROJECT VICINITY........................................................................................................ 7
Streams and Stream Crossings ................................................................................. 7
Wetlands ........................................................................................................................ 8
Project Action Area .................................................................................................... 10
Environmental Setting ............................................................................................... 12
LIST OF SPECIES ......................................................................................................... 13
SPECIES AND HABITAT ............................................................................................. 15
Oregon Spotted Frog ................................................................................................. 15
Yellow-Billed Cuckoo ................................................................................................. 17
Puget Sound Steelhead Critical Habitat ................................................................. 19
EFFECTS of the Action ............................................................................................... 20
Direct Effects ............................................................................................................... 20
Salmonid Species .................................................................................................. 22
Vegetation and Wildlife.......................................................................................... 22
Indirect Effects ............................................................................................................ 22
Interrelated and Interdependent Actions ................................................................ 23
Minimization MEASURES .......................................................................................... 24
Mitigation ..................................................................................................................... 24
EFFECT DETERMINATIONS ...................................................................................... 25
Yellow-Billed Cuckoo ................................................................................................. 25
Oregon Spotted Frog ................................................................................................. 25
Puget Sound Steelhead Proposed Critical Habitat ............................................... 26
REFERENCES ..................................................................................................................i
Personal Communications .........................................Error! Bookmark not defined.
APPENDIX A – Hydraulic Summary ..........................................................................ii
APPENDIX B – Rolling Hills Creek Restoration Plan ............................................i
APPENDIX C – Existing Conditions Plan Sheets ...................................................i
I-405/SR 167 Direct Connector Project Page ii
LIST OF TABLES
Table 1 – ESA Listed Species and Effect Determinations
Table 2 – Summary of Wetlands in the Direct Connector Project Vicinity
Table 3 – Species and Critical Habitats Addressed in this BA Update
Table 4 – Species and Critical Habitats Not Addressed in this BA Update
Table 5 – Wetland Impact Summary
Table 6 – Stream Impact Summary
Table 7 – Buffer Impact Summary
LIST OF FIGURES
Figure 1 – Project Area Map
Figure 2 – Fish Passage/Stream Relocation Map
Figure 3 – Project Action Area Map
I-405/SR 167 Direct Connector Project Page iii
INTRODUCTION
This Biological Assessment (BA) update for the Interstate 405 (I-405) I-5 to State
Route (SR) 169 Stage 2 – Widening and SR 515 Interchange Project was
prepared to address new listings and proposed critical habitat under the
Endangered Species Act (ESA). In addition to addressing newly listed species
and habitats, current project information is being provided on the I-405, SR 167
High Occupancy Vehicle Direct Connect Ramp Project (Direct Connector
Project), which was addressed in the original BA, but has not been funded for
construction. The project has been re-evaluated for NEPA compliance which
facilitated the need for an update to ESA documentation.
Background and Consultation History
The original BA was submitted on June 26th, 2007, and requested consultation
for the following species/critical habitats and effect determinations:
Species
x Chinook salmon (Oncorhynchus tshawytscha) – May affect, likely to adversely affect
x Steelhead trout (Oncorhynchus mykiss) – May affect, likely to adversely affect
x Bull trout (Salvelinus confluentus) – May affect, likely to adversely affect
Critical Habitats
x Puget Sound ESU Chinook salmon – May affect, likely to adversely affect
x Coastal-Puget Sound ESU Bull trout – May affect, likely to adversely affect
A Biological Opinion (BiOp) (USFWS Log No: 12410-2007-F-0416; NMFS
Tracking No: 2007/04219) was prepared jointly by the United States Department
of Fish and Wildlife (USFWS), and National Marine Fisheries (NMFS) and
submitted to WSDOT March 3rd, 2008. The BiOp indicated that both services
concurred with the findings in the BA and an incidental take statement was
provided.
PROJECT DESCRIPTION
Project Overview
The Direct Connector Project will construct a portion of the project elements
evaluated in the I-405, Tukwila to Renton (I-5 to SR 169 – Phase 2)
Environmental Assessment (March 2008) and Finding of No Significant Impact
and Final Section 4(f) Evaluation (July 2008).
This project will construct a new direct connector ramp for a high occupancy
vehicle (HOV)/express toll lane (ETL) operation in each direction between SR
167 south leg high occupancy toll (HOT) lanes and I-405 north leg HOV lanes.
I-405/SR 167 Direct Connector Project Page 1
The project will reconstruct sections of northbound I-405 and northbound and
southbound SR 167 to open up the medians to make room for the new direct
connector ramps, construct a new HOV/ETL structure between SR 167 and I-
405, widen/replace the I-405 bridge over SR 515 (Bridge Number 405/016),
construct new retaining walls, and relocate a noise barrier. The project will modify
local roadways, including East Valley Road and S 14th Street, related to the
interchange improvements and I-405/SR167 widening. Other elements include:
sign bridges; ITS and tolling equipment; storm water management facilities;
Rolling Hills Creek channel realignment along the east side of SR 167 (MP 25.93
to I-405); and installation of a fish passable water crossing structure for Rolling
Hills Creek under SR 167 at the S 19th Street alignment (Figure 1).
I-405/SR 167 Direct Connector Project Page
2
Figure 1. Project Area Map
The project is being completed using the Design-Build method of delivery. All
descriptions of project actions and construction methods herein are based on a
preliminary design concept which is subject to change as part of the final design
process. Once selected, the Design-Builder will be responsible for producing a final
design which WSDOT will review and approve before it is released for construction.
I-405/SR 167 Direct Connector Project Page
3
Stormwater
The design of the Project stormwater improvements will generally utilize as much
of existing drainage system as possible and provide treatment facilities that
conform to accepted best management practices (BMPs) outlined in the current
WSDOT Highway Runoff Manual (HRM). Final design will identify the work
involved with highway runoff collection and conveyance, so the extent of reused
and new systems is not known at this time. All sites selected for flow control
facilities will be placed outside of the 100-year floodplain. Final design may
result in changes to the proposed stormwater treatment system, but no stage of
the project, including the Direct Connector Project, will increase pollutant
concentrations discharged to receiving waterbodies. Additionally, the
construction of any new stormwater facilities will be timed such that the loading
and concentration targets will be met for the Direct Connector Project as well as
each future construction stage/project.
The entire project addressed in the original BA was expected to increase the
pollutant generating impervious surface (PGIS) area by 69.60 acres across three
drainage basins. The Direct Connector Project occurs entirely within the Lower
Green River and Springbrook Creek sub-basins and includes approximately 7.36
acres of the total new PGIS. The final design of the Direct Connector Project may
result in changes to the number, type, size, and location of the proposed
drainage facilities for the Project as long as the total BMP catchment area from
the original consultation is achieved, along with the HRM requirements. The
conceptual design for the Direct Connector Project includes the following
stormwater components:
x Existing stormwater collection and conveyance systems will be modified or
additional systems will be constructed as required for the new roadway
geometry and as required for stormwater management using equivalent
catchment areas.
x Three new flow control facilities will be constructed.
x WSDOT HRM compliant enhanced runoff treatment BMPs will be
constructed or modified as required to meet environmental commitments
made through NEPA and prior ESA consultation on the project.
x One culvert under SR 167 will be replaced by a new fully fish passable
structure.
x A section of Rolling Hills Creek will be extended for stream impact
mitigation east of the widened section of SR 167.
Additional details on the stormwater design concept for the Direct Connector
Project are provided in a hydraulic summary (Appendix A).
I-405/SR 167 Direct Connector Project Page
4
Fish Passage
The Direct Connector Project will address one fish passage barrier on Rolling
Hills Creek which crosses SR 167 at milepost (MP) 26.08 through a 3 foot by 4
foot box culvert. The existing culvert has been identified as a partial barrier to fish
passage due to flow velocity. The conceptual design for a fully fish passable
structure includes moving the crossing to the south, to MP 25.93 in order to
daylight approximately 1,400 feet of stream rather than piping the stream for long
distances under local roads and parking lots as in its current configuration. The
new crossing structure will include a minimum channel width of 10 feet, and will
be constructed first, allowing the stream to remain in its current location until
construction is complete. A map of the stream relocation is provided in Figure 2.
I-405/SR 167 Direct Connector Project Page
5
Figure 2. Fish Passage/Stream Relocation Map
A new stream channel will be constructed from a culvert outlet along the
northbound I-405 on-ramp from SR 167, to the location where the new culvert will
be constructed. The new channel will be stabilized with appropriately sized
streambed sediment and gravel, and woody riparian planting and seeding. Once
I-405/SR 167 Direct Connector Project Page
6
the new channel is graded, planted, stabilized, and connected to the new fully
fish passable structure, flow will be slowly introduced from the existing channel at
the upstream end. After flow has been completely diverted to the new channel
and crossing, the existing channel be filled for future widening and the remaining
box culvert will be re-purposed as a stormwater facility. A restoration plan
depicting a conceptual layout of the new stream channel and associated riparian
vegetation is provided in Appendix B.
Road Construction
The Direct Connector Project will reconstruct portions of the I-405 and SR 167
interchange to accommodate direct connector ramps and tolling infrastructure.
This work will involve significant use of heavy equipment for earthwork, ground
improvements (including pile driving), demolition, paving, and utility work. New
flyover ramps will be supported by columns most likely installed in drilled shafts.
A gas pipeline that runs parallel to SR 167 will be relocated approximately 200
feet to the east, to remain outside of the paved roadway through all remaining
construction phases.
Project Schedule
The Direct Connector Project is not funded for construction. Should funding
become available, the project will be completed utilizing the Design Build method
of delivery, including final design and construction. The project would be
constructed over 2-3 years.
PROJECT VICINITY
Streams and Stream Crossings
There are two tributaries to Springbrook Creek that occur within the project
vicinity. Rolling Hills Creek (Stream 09.SC-2.8) and East Fork Panther Creek
(Stream 09.SC-25.7) are small urban streams that are heavily manipulated as a
result of development in and around the City of Renton. Stream locations within
the project area can be seen in Appendix C (Existing Conditions Sheets).
From its headwaters southeast of the junction of I-405 and Talbot Road, Rolling
Hills Creek eventually flows northward between Talbot Road and S Puget Drive
and into the project area approximately 200 feet south of I-405. From this
intersection, Rolling Hills Creek flows through a series of culverts under several
commercial parking lots to where it ultimately daylights on the north side of I-405
into an open channel between I-405 and a parking lot associated with several
local businesses including the Renton Cinema 8 and Triton Tower One. The
creek then flows south in a culvert under the I-405/SR 167 Interchange, into an
I-405/SR 167 Direct Connector Project Page
7
open channel that runs parallel to the NB SR 167 ramp to NB I-405 for
approximately 520 feet, under SR 167 and local streets, that eventually outlets to
Springbrook Creek approximately 2,600 feet downstream. During high flow
events, a portion of the flow from the section of Rolling Hills Creek between I-405
and the Renton Cinema 8 parking lot is directed into an overflow culvert that also
flows south under the I-405/SR 167 Interchange, before daylighting in the
Panther Creek Wetlands complex. This stream contains no ESA-listed fish but
potentially has resident fish including sculpin, three-spined stickleback, cutthroat
trout, as well as coho salmon.
The East Fork of Panther Creek flows out of the Panther Creek Wetlands near
SR 167 milepost 25.66 through a fully fish passable culvert (constructed by
WSDOT in 2012) under SR 167. After flowing under SR 167 and East Valley
Road, Panther Creek enters a large wetland complex west of East Valley Road
containing forested vegetation. The creek continues through this wetland to
where it flows into Springbrook Creek approximately 2,600 feet to the west. The
east fork of Panther Creek has a limited stream buffer, mostly established by
WSDOT as part of a previous project. This creek may be used by coho and
Chinook salmon and cutthroat and steelhead trout as rearing habitat because of
its association with Springbrook Creek.
Wetlands
There are 13 wetlands in the Direct Connector Project vicinity. The majority of
them are small, palustrine scrub-shrub and emergent wetlands with limited
habitat value or hydrologic function. A summary of wetlands in the vicinity is
provided in Table 2.
I-405/SR 167 Direct Connector Project Page
8
Table 2. Summary of Wetlands in the Direct Connector Project Vicinity
Notes:
1)Washington State Wetland Rating System for Western Washington (Ecology 2006)
2) City of Renton Critical Area Requirements (RMP 4-3-050)
3) From Classifications of Wetlands and Deep Water Habitats of the United States (Cowardin 1979)
PEM=Palustrine emergent; PSS=Palustrine Scrub-Shrub; PFO=Palustrine Forested, PAB=Palustrine Aquatic
Bed.
The highest quality wetlands are Wetlands 24.7R-A, B, and C. This
interconnected wetland complex is locally referred to as the Panther Creek
Wetlands, although the complex includes portions of both Panther Creek and
Rolling Hills Creek. The complex is divided into three units by berms with cross
culverts running through them. This wetland complex is over sixty acres in size
and includes forested zones, as well as some permanently ponded areas
dominated by aquatic bed vegetation. Common herbaceous vegetation includes
reed canarygrass (Phalaris arundinacea), cattails (Typha latifolia) and soft rush
(Juncus effuses). Shrub-dominated areas typically include Sitka willow (Salix
sitchensis), redosier dogwood (Cornus stolonifera) and large stands of
Himalayan blackberry (Rubus armeniacus).
The remaining wetlands tend to be small and confined by adjacent impervious
surfaces. Wetland 2.2R-B and 2.31R are small depressions in roadside ditches.
Wetland 2.31 is dominated by roadside grasses and receives SR 167 runoff.
Wetland 2.2R-B is located in a deep ditch along the I-405 off ramp to southbound
SR 167 and contains a few shrubs, with a blackberry understory extending over
the wetland from the steep embankments. Wetlands 25.0L, 25.7L, and 25.8L are
linear features adjacent to SR 167 that provide drainage for adjacent paved
surfaces. They typically have shrubby communities of alder and willow with
intermittent pockets of herbaceous vegetation at the lowest elevations.
Wetland/Stream Size (ft2)Ecology
RatingA
Local
RatingB
Cowardin
ClassificationC
2.2R-B 856 IV N/A PSS
2.31R 309 IV N/A PEM
2.6R 6,424 III 3 PSS, PEM
2.7R 10,890 III 3 PSS, PEM
2.9L 45,738 III N/A PSS
2.82R 2,454 IV 3 PFO,PSS, PEM
24.7R-A 1,948,747 II 1 PFO, PSS, PEM
24.7R-B 419,200 II 1 PFO, PSS, PEM
24.7R-C 302,750 II 1
PFO, PSS, PEM,
25.0L 180,316 III 3 Forested
25.7L 12,702 III 3 PSS
25.8L 501,508 III 3 PSS, PEM
25.9L 4,499 III 3 PSS
I-405/SR 167 Direct Connector Project Page
9
Himalayan blackberry is dominant in the buffers (and extending into the
wetlands) of most of the wetlands in the project vicinity. Wetland 2.6R is located
just south of I-405 near Talbot Road. It is a small depressional wetland with steep
sides dominated by Himalayan blackberry. The wetland includes a stand of
shrubs on the west side and reed canarygrass at the lowest points.
None of the wetland areas are known to be occupied by listed fish, amphibian, or
other vertebrate species.
Project Action Area
This section describes the action area for the Project. The action area is defined
as the geographic area potentially affected by the Project (Figure 3). The action
area established in the original consultation has not changed. The furthest
reaches of the action area can be affected by the high noise activities associated
with pile driving for ground improvements. Construction noise will extend a
maximum distance of one mile from the immediate work area before attenuating
to background levels. The aquatic portion of the action area for the Direct
Connector Project includes the Rolling Hills Creek crossing within the Panther
Creek Wetland complex. There is potential for sediment mobilization associated
with the fish passage work, but sediments will not extend more than 300 feet
downstream because the stream is piped and mixes with significant amounts of
drainage from the City of Renton.
I-405/SR 167 Direct Connector Project Page
10
Figure 3. Project Action Area
Aquatic action area
I-405/SR 167 Direct Connector Project Page
11
Environmental Setting
The project environmental baseline is described in detail in the original BA. This
section of the BA Update will focus on the specific conditions of drainage basin
surrounding the Direct Connector Project area.
The bulk of the project work occurs in the Springbrook Creek sub-basin of Water
Resource Inventory Area (WRIA) 9. The Springbrook Creek subbasin enters the
mainstem Green River via the Black River at RM 11.0. With an estimated
mainstem stream length of 12.0 miles, and approximately 19.1 miles of tributary
streams and 3.8 miles of drainage ditches, it is the largest subbasin in the lower
Green River Basin (Williams et al. 1975).
The Springbrook Creek subbasin drains an area of about 15,763 acres. The
basin is comprised of two distinct physical settings. In the eastern half of the
subbasin, rolling hills rise to elevations of about 525 feet above the valley floor.
In this area, the origins of stream courses are often not well defined. Slopes in
the subbasin range from near 0 to 70 percent. One significant lake is present
(Panther Lake) along with several smaller ponds and wetlands. Creeks
originating from these upland sources drop abruptly through sharply defined
steep canyons to the valley floor where stream gradients flatten quickly.
Typically, these canyons are short, with high gradients and generally are not
accessible to anadromous salmonids (Kerwin 2001).
In 1958, an earthen dam was constructed on the Black River approximately
1,000 feet upstream of the confluence with the Green River. This blocked
passage of anadromous fish into Springbrook Creek. Besides impeding
salmonid migration into the Springbrook Creek system, this dam blocked flows
from the Green River from backwatering into the remnant Black River, which
could have provided some refuge habitat for salmonids during high flows. In
1972, the U.S. Soil Conservation Service replaced the dam with the Black
River Pumping Station (BRPS), which currently is operated by King County.
Although it is equipped with upstream and downstream fish passage facilities, the
BRPS can act as a barrier to migration of juvenile and adult salmonids due to
inadequate screening, fish weir design, and operation schedule (Kerwin 2001).
There are several barriers along Springbrook Creek and associated tributaries.
Between the SR 167 crossing and Talbot Road, the creek flows through a
private trout farm that presents a barrier for migrating anadromous salmonids
under most stream flow conditions. Several sections of Springbrook Creek are
so choked with invasive reed canarygrass and vegetation that they serve as
partial barriers. If the bypass reach is dewatered, then it would also serve as a
barrier to downstream migration.
Upstream of the trout farm, Springbrook Creek flows through a 30-foot-long
I-405/SR 167 Direct Connector Project Page
12
culvert and standpipe that is sloped at approximately 100 percent in the vicinity
of Talbot Road. On the South Fork of Springbrook Creek, there is a concrete
pad and notched weir that likely is a barrier to upstream and downstream
migrating anadromous and resident fish. Water quality may serve to act as a
barrier to anadromous migrating fish in the lower reaches of Mill and
Springbrook Creeks (Kerwin 2001).
In the immediate vicinity of I-405, Springbrook Creek is largely contained within
concrete walls for flood control purposes. Springbrook Creek flows under I-405
under two bridges that were constructed as part of the Renton Nickel
Improvement Project. Downstream of where Springbrook Creek flows under SW
Grady Way, Springbrook Creek is no longer contained in a concrete channel, but
is still confined within an incised riprapped channel.
Riparian vegetation surrounding Springbrook Creek is a mixture of alder and
willow species, Himalayan blackberry, and sedges (Carex spp.). Conifers are
almost non-existent and, in those areas where shade is absent, reed
canarygrass is abundant. Riparian habitat within this creek does not meet the
NMFS criteria for properly functioning habitat and is a limiting factor to natural
salmonid production (Kerwin 2001).
Vegetation in the vicinity of Rolling Hills Creek (a tributary to Springbrook
Creek) consists of wetland herbaceous plants, reed canarygrass, willows,
cottonwoods, and some Oregon ash (Fraxinus latifolia).
Springbrook Creek is listed on Ecology’s 303(d) list for exceedances of fecal
coliform and dissolved oxygen (DO).
LIST OF SPECIES
Date obtained species list from the USFWS website (USFWS 2015):
January 7, 2015
Date obtained species list from the NMFS website (NMFS 2015):
January 7, 2015
At the time of this BA Update, critical habitat for Puget Sound Steelhead has
not been designated. However, it is addressed, and a provisional effect
determination has been provided.
Table 3 details the ESA listed species and critical habitat addressed in this BA
Update. Species and habitats that are sufficiently addressed by the original BA
have been omitted from this document.
I-405/SR 167 Direct Connector Project Page
13
Table 3. Species and Critical Habitats Addressed in this BA Update
Species Status Agency
Critical
Habitat
Yellow-billed cuckoo
(Coccyzus americanus)Threatened USFWS None
designated
Puget Sound DPS
Steelhead trout
(Oncorhynchus mykiss)
Threatened
NMFS Proposed
Oregon spotted frog
(Rana pretiosa)Threatened USFWS
Proposed
The following species, and/or designated or proposed critical habitat may occur
within King County, as indicated by the County species list, but are not being
addressed in this BA. No suitable habitat exists within the project action area for
the species listed in Table 4. Examination of the Priority Habitats and Species
maps from WDFW and an analysis of habitat types in the action area showed that
these species do not occur in or near the action area.
Table 4. Species and Critical Habitats Not Addressed in this BA Update
Species Status Agency Critical Habitat
Canada lynx
(Lynx canadensis)Threatened USFWS
None in Action
Area
Gray wolf
(Canis lupus)Endangered USFWS
Not
designated
Grizzly bear
(Ursus arctos)
Threatened USFWS
Not
designated
Marbled murrelet
(Brachyramphus marmoratus)Threatened USFWS
None in Action
Area
Taylor’s checkerspot butterfly
(Euphydryas editha taylori)Endangered USFWS
Not in Action
Area
Streaked horned lark
(Eremophila alpestris strigata)Threatened USFWS
Not in Action
Area
Northern spotted owl
(Strix occidentalis caurina)Threatened USFWS
None in Action
Area
Golden paintbrush
(Castilleja levisecta)Threatened USFWS
Not
designated
Fisher
(Martes pennanti)Proposed
threatened
USFWS None in Action
Area
I-405/SR 167 Direct Connector Project Page
14
SPECIES AND HABITAT
Oregon Spotted Frog
On August 29, 2014, The U.S. Fish and Wildlife Service (Service) published a
final rule to list the Oregon spotted frog (Rana pretiosa)as a threatened species
under the Endangered Species Act (50 CFR 17 51658-51710). The Service will
make a final determination on Oregon spotted frog critical habitat sometime in
the future.
The Oregon spotted frog is a medium sized frog that ranges from about 1.7 to 4.1
inches (44 to 105 millimeters) in body length (Federal Register 2014). It is
named for the characteristic black spots covering the head, back, sides, and
legs. The dark spots have ragged edges and light centers, usually associated
with a tubercle or raised area of skin. Adults range from brown to reddish brown
but tend to become redder with age. The Oregon spotted frog has a weak call
consisting of a rapid series of six to nine low clucking notes described as
sounding like a distant woodpecker’s tapping. Oregon spotted frogs burrow in
muddy, silty, substrate; clumps of emergent vegetation, woody accumulations
within a creek, and holes in creek banks when inactive during periods of
prolonged or severe cold. This species remains active during the winter in order
to select microhabitats that can support aerobic metabolism and allow it to evade
predators. As with other ranid frogs, most daily movements are relatively short
(10s of feet) and seasonal movement may be 100s of feet. These frogs
occasionally will move a few miles, and it is presumed that Oregon spotted frog
habitats are connected for purposes of genetic exchange when occupied/suitable
habitats fall within a maximum movement distance of 3.1 miles.
This species typically begins to breed at three years of age. Breeding occurs in
February or March at lower elevations and in late May or early June at higher
elevations. Females may deposit egg masses at the same location in successive
years in shallow, often temporary, pools no more than six inches deep. Eggs
usually hatch within three weeks after oviposition. Tadpoles are grazers, having
rough tooth rows for scraping plant surfaces and ingesting plant tissue and
bacteria. They also consume algae, detritus, and probably carrion. Tadpoles
then metamorphose into froglets during their first summer. Post-metamorphic
Oregon spotted frogs feed on live animals, primarily insects.
Eggs are extremely vulnerable to desiccation and freezing as a result of the
species’ laying habits. Although egg masses are occasionally laid singly, the
majority of egg masses are laid communally in groups of a few to several
hundred in shallow, often temporary, pools of water; gradually receding
shorelines; on benches of seasonal lakes and marshes; and in wet
meadows. These sites are usually associated with the previous year’s emergent
vegetation, are generally no more than 14 inches deep, and most of these sites
dry up later in the season. Shallow water is easily warmed by the sun, and
warmth hastens egg development. Traditional egg laying habitat is limited, and
I-405/SR 167 Direct Connector Project Page
15
adults may have limited flexibility to switch sites. Based on egg mass census
data, the USFWS estimates the minimum Oregon spotted frog population in
Washington was at least 7,368 breeding adults in 2012.
The Oregon spotted frog inhabits emergent wetland habitats in forested
landscapes, although it is not typically found under forest canopy. Historically,
this species was also associated with lakes in the prairie landscape of the Puget
lowlands. Oregon spotted frogs may no longer occur in as much as 76-90
percent of their historically documented range. This is the most aquatic native
frog species in the Pacific Northwest, as all other species have a terrestrial life
stage. It is almost always found in or near a perennial body of water, such as a
spring, pond, lake, sluggish stream, irrigation canal, or roadside ditch. Oregon
spotted frogs can make use of a variety of pond types as long as there is
sufficient vegetation and seasonal habitat available for breeding, summer
feeding, and overwintering. Full solar exposure seems to be a significant factor in
breeding habitat selection.
Genetic studies indicate that gene flow among sites has been very low, even on
small geographic scales. Due to Oregon spotted frogs’ highly aquatic habits,
connectivity between Oregon spotted frog sites depends on the connectivity of
streams, rivers, and lakes. Gene flow (based on both microsatellite and
mitochondrial analyses) is extremely low beyond 6 miles, and most Oregon
spotted frog populations are separated by more than 6.2 miles.
Threats to Oregon spotted frog include conversion of wetlands to other habitats,
including natural succession of open wetland habitat to forest habitat, other
associated hydrological changes (changes in flood regimes/ dam management
and water drawdowns which desiccate habitat), non-native species
(bullfrog/warm water fish predation, reed-canary grass invasion), the inadequacy
of existing regulator mechanisms, and issues associated with small
populations. Some federal and state programs promote tree planting for fish
habitat restoration and curtailment of livestock grazing in riparian areas may have
negative effects on Oregon spotted frog because they allow for the expansion of
woody vegetation, degrading frog habitat. Although Oregon spotted frog is
affected by several pathogens, including chytrid fungus (confirmed at all
Washington and Oregon sites), diseases are not thought to significantly affect
populations. Historical loss of wetlands has been extensive throughout the range
of the species, and is the primary reason for the absence of the species from as
much as 90 % of its former range. Much of the known frog habitat is dominated
by reed canarygrass, which can negatively affect vegetation diversity, site
hydrology, and vegetation cover; these frogs appear to actively avoid areas with
high reed canarygrass density.
Natural disturbance factors that helped maintain Oregon spotted frog habitat
included meandering rivers and flooding of river floodplains, beaver dams, and
summer fires. All served to remove woody vegetation and create openings in
river floodplains and wetlands, and all factors currently operate at reduced
rates. Many of the Oregon spotted frog breeding locations comprise less than 50
I-405/SR 167 Direct Connector Project Page
16
adult frogs, are isolated from other breeding locations, and may already be
stressed by other factors, such as drought or predation, and are more vulnerable
to random, naturally occurring events. Six major Oregon spotted frog haplotypes
have been identified based on mitochondrial genetic data; there is low genetic
diversity within and high genetic differentiation among the six groups, and each
of these groups has the signature of complete isolation, with two groups showing
indications of recent genetic drift. Where Oregon spotted frog locations have
small population sizes and are isolated, their vulnerability to extirpation from
factors such as fluctuating water levels, disease, and predation increases. The
minimum amount of habitat thought to be required to maintain an Oregon spotted
frog population is about 10 acres. Smaller sites generally have a small number of
frogs and are more vulnerable to extirpation.
Species and Habitat Presence
There are significant ponded areas within the Panther Creek Wetlands that could
provide suitable habitat for Oregon spotted frog. However, the hydrology in this
wetland complex is highly influenced by adjacent land use, and ponded areas are
artificially large due to significant stormwater inputs. The hydrology and
vegetation that would support Oregon spotted frogs are subject to rapid change,
depending on present or future manipulations to drainage of surrounding
developed areas.
There are no recent records of Oregon Spotted Frog in King County. It is highly
unlikely to be present in the project footprint due to the distance to known
occupied habitats, and the lack of hydrologic connections between. The U.S.
Fish and Wildlife Service has provided WSDOT with preliminary guidance on
areas that may be occupied by Oregon spotted frog. These areas of influence
include 19 5
th and 6th field hydrologic unit codes (HUCs) in Washington State.
The closest area of influence is Green River Kent (a historical site), more than 3
miles from the action area boundary.
There is no proposed Oregon spotted frog critical habitat within the project action
area.
Yellow-Billed Cuckoo
The USFWS listed the western distinct population segment (DPS) of the yellow-
billed cuckoo (Coccyzus americanus) as threatened on October 3, 2014. The
western states where cuckoos are found include Washington, Idaho, Montana,
Oregon, California, Nevada, Wyoming, Utah, Colorado, Arizona, New Mexico,
and Texas. No critical habitat was proposed in Washington State.
The yellow-billed cuckoo ranges across all of North America, but eastern and
western birds are separated by the Continental Divide (generally the crest of the
Rocky Mountains based on watershed boundaries), the watershed divide
between the Rio Grande and Pecos River, and the Chihuahuan Desert in
I-405/SR 167 Direct Connector Project Page
17
Mexico. Both eastern and western yellow-billed cuckoos are highly migratory,
and the two populations may spend winters in overlapping regions in South
America. There is an extremely low level of interchange (if any at all) between
the two populations during the breeding season. Eastern and western birds differ
by the several characteristics: 1) yellow-billed cuckoos in western North America
arrive on the breeding grounds 4 to 8 weeks later than eastern yellow-billed
cuckoos at similar latitude, 2) yellow-billed cuckoos in western North America are
generally larger, with significantly longer wings, longer tails, and longer and
deeper bills, 3) birds in western North America produce larger eggs (1.2 percent
longer, 0.6 percent wider, and 3.2 percent heavier) with thicker eggshells, 4)
Juvenile yellow-billed cuckoos in the east have yellow bills while juvenile yellow-
billed cuckoos in the west have all-black bills.
The yellow-billed cuckoo feeds primarily on larger invertebrates such as
caterpillars, cicadas, katydids, and grasshoppers. In California and Arizona,
yellow-billed cuckoos rarely begin nesting before mid-June. Nesting in western
North America continues through August, and up to three broods can be raised in
a season if the prey base is sufficient. Yellow-billed cuckoos build an open cup
nest with a loose saucer-shaped stick construction. Both parents build the nest,
incubate, and tend the young. Clutch size varies from two to five eggs depending
on the available food supply. The incubation and nestling periods are short, with
the eggs hatching in 11–12 days and young fledging in 5–7 days. Incubation
begins when the first egg is laid and the young hatch asynchronously, with the
oldest near fledging while the youngest has just hatched.
Nesting habitat for the western yellow-billed cuckoo is in low to moderate
elevation riparian hardwood woodlands that cover 50 acres or more within arid to
semiarid landscapes. In California, yellow-billed cuckoos are most likely to be
found in patches of willow– cottonwood riparian habitat greater than 200 acres in
size. Throughout the western DPS range, a large majority of nests are placed in
willow trees, but alder (Alnus spp.), cottonwood, mesquite, walnut (Juglans spp.),
box elder, sycamore, and tamarisk are also used. Other riparian hardwood trees
that provide overstory canopy for cuckoo include sycamore (Platanus sp.), ash
(Fraxinus sp.), and mesquite (Prosopis sp.). Dense riparian vegetation with an
understory component is important for nesting cuckoos. Most nests are placed
on well-foliaged horizontal branches at sites with dense canopy cover above the
nest. Much of the habitat work on cuckoos has come from California and Arizona,
so these are general guidelines.
The yellow-billed cuckoo is extremely rare in Washington State (WDFW reports
12 records between 1950 and 2000 {four in western Washington, eight in eastern
Washington}, with three reports since 2000: near Lind (Adams Co.) in 2001, near
Eureka (Walla Walla Co.) in June 2007, and from Little Pend Oreille National
Wildlife Refuge (Stevens Co.) in June 2012. This equates to about 1 confirmed
record every 4 years. There has not been confirmed breeding in Washington
since 1934.
I-405/SR 167 Direct Connector Project Page
18
Species and Habitat Presence
The Panther Creek Wetland complex and surrounding forested upland is one of
the largest (nearly 80 acres) unbroken habitat patches in the urban parts of
greater Seattle. The area provides foraging and dispersal habitat for many
migratory birds, and presumably could be suitable for yellow-billed cuckoos.
However, yellow-billed cuckoos tend to avoid noisy areas, making it unlikely they
would pass through this site. The project is just a mile south of the Renton
Municipal Airport and includes some of the most travelled highways in the state.
Puget Sound Steelhead Critical Habitat
Critical habitat has yet to be designated for steelhead trout, but was proposed
for designation on January 14, 2013. Proposed critical habitat includes
Springbrook Creek, but not Rolling Hills Creek. Proposed steelhead critical
habitat is not within the action area for the Direct Connector Project.
I-405/SR 167 Direct Connector Project Page
19
EFFECTS OF THE ACTION
Direct Effects
Direct effects associated with the project will primarily come from filling of
wetlands and streams, and to a lesser extent, their associated buffers. There will
be up to 7 acres of vegetation removal within the project footprint. A portion of
that area occurs in a residential area south east of the I-405/SR 167 interchange,
where there is very little terrestrial habitat and no aquatic habitat.
Permanent and aquatic resource impacts are as follows:
Table 5. Wetland Impacts Summary
Notes:
A)Indirect Permanent impacts occur due to hydrology alterations in undisturbed areas as a
result of culvert replacement.
B)Permanent conversion impacts occur where wetlands are graded to create a stream
channel. The wetland is permanently converted to stream.
C)Long-term temporary impacts are those that can be restored by re-planting, but will take
longer than one year to return to a pre-impact condition.
Impacted
Wetland Category
Impact Type (ft2)
Direct
Permanent
Indirect
PermanentA
Permanent
ConversionB Long-term
TemporaryC
2.2R-B IV 856 N/A N/A N/A
2.31R III 309 N/A N/A N/A
2.6R III 6,424 N/A N/A N/A
24.7R-A II 3,680 N/A N/A 4,770
24.7R-B II 38,840 N/A 4,190 14,410
24.7R-C II 74,365 109,720 52,100 26,410
25.0L III 840 N/A N/A 1,890
25.7L III 1,020 N/A N/A 700
25.8L III 1,440 N/A N/A 1,000
25.9L III 4,449 N/A N/A N/A
TOTAL (ft2)132,273 109,720 56,290 49,180
TOTAL (Acres)3.02 2.52 1.29 1.13
I-405/SR 167 Direct Connector Project Page
20
Table 6. Stream Impacts Summary
Notes:
A)Stream types are defined by the Washington State Department of Natural Resources.
Type F streams are those that are known to be used by fish, or meet the physical criteria
to be potentially used by fish. Fish streams may or may not have flowing water all year;
they may be perennial or seasonal.
Table 7. Wetland Buffer Impacts Summary
The impacts to wetlands, streams, and buffers are not expected to measurably
affect ESA-listed species due to a lack of species presence. The functions
provided by the aquatic resources being impacted will continue to be provided by
adjacent wetlands and buffers, and Rolling Hills Creek is being relocated to the
east and restored to provide better instream and riparian function than is
currently present.
The project will create approximately 7.36 acres of new PGIS. The vast majority
of runoff from new PGIS will flow into media filter drain treatment facilities, then
detention ponds, and eventually, Rolling Hills Creek. This will not affect ESA-
listed species because none are present in Rolling Hills Creek. A small portion of
new PGIS (approximately 1,000 ft2) will drain into existing media filter drains,
before entering The Panther Creek Wetlands, and Panther Creek, which does
contain some suitable habitat for Puget Sound steelhead.
During active construction work, when grading, excavation, drilling, and pile
driving are occurring, there will be visual and noise disturbances that can affect
Impacted Stream
WDNR
Stream
TypeA
Impact Type-ft2 (acres)
Permanent Temporary
East Fork Panther Creek F N/A N/A
Rolling Hills Creek F 2,420 (0.06)
N/A
TOTAL (ft2)2,420 N/A
TOTAL (Acres)0.06 N/A
Impacted Wetland Category
Impact Type (ft2)
Permanent Temporary
24.7R-B II 270 210
24.7R-C II 16,480 1,900
25.0L III 1,750 450
25.7L III 6,200 1,120
25.8L III 11,100 2,100
TOTAL (ft2)35,800 5,780
TOTAL (Acres)0.82 0.13
I-405/SR 167 Direct Connector Project Page
21
listed species. The support structure for new flyover ramps will be installed with
drilled shafts. Pile driving for ground improvements along the widened section of
SR 167 will not occur within the ordinary high water mark of Rolling Hills Creek,
and it will not occur within 1,000 feet of Panther Creek. Work in and around
Rolling Hills Creek will be limited to the workdays between June 16th to
September 30th each construction year, to limit exposure to resident fish that may
be present. Noise and visual disturbances are not expected to affect ESA-listed
fish, or the Oregon spotted frog due to the lack of species presence in the areas
of disturbance.
The yellow-billed cuckoo may be sensitive to the high noise generated by pile
driving, concrete demolition, paving, and general construction activities, but they
will typically avoid high noise areas. Construction noise generated by the Direct
Connector Project will extend approximately 1 mile in all directions from the
immediate work areas, but the project vicinity includes permanent noise
generating fixtures including Renton Municipal Airport, and the I-5 and I-405
interchange, with the Sea-Tac International Airport located less than 4 miles
away. The daily high ambient noise levels in the project vicinity make it unlikely
that project-related noise will have a measurable effect on the yellow-billed
cuckoo.
Salmonid Species
The project will have no direct effects to ESA-listed salmonids because they are
not present in the action area. Work in and around Rolling Hills Creek does have
the potential to impact non-listed resident fish which could include cutthroat trout,
sculpin, coho, and three-spined stickleback.
Vegetation and Wildlife
The project includes up to 8 acres of vegetation disturbance. Most disturbed
areas of will be restored after construction is complete, but there may be up to
0.28 acres cottonwood forest permanently removed, which would reduce
perching opportunities for the yellow-billed cuckoo, if the species were using the
site. This is a minimal loss of habitat, as the Panther Creek Wetland complex and
adjacent uplands will still provide upwards of 20 acres of mixed conifer, big-leaf
maple, cottonwood and Pacific willow forest adjacent to the shrubby and
herbaceous wetland/stream areas.
The conversion of wetland area to stream/riparian resulting from the re-alignment
of Rolling Hills Creek will change a primarily wetland herbaceous community to a
woody shrub/forest community with an open stream channel. This project effect
on vegetation could result in a loss of suitable Oregon spotted frog habitat.
However, Oregon spotted frog is not known or expected to occur in this area.
Indirect Effects
I-405/SR 167 Direct Connector Project Page
22
Indirect effects associated with the project will result from the replacement of the
Rolling Hills Creek culvert. A fully fish passable structure will permanently alter
drainage of the Panther Creek Wetlands (Wetlands 24.7R-A, B, and C). It is not
clear what long-term effects will result from the altered hydrology of the wetland,
but it is possible the result will be the permanent loss of wetland hydrology and
function for approximately 2.52 acres of the Panther Creek Wetlands. However,
the presence of the new channel section and improved riparian function will
improve fish habitat. The new channel section could provide rearing and foraging
opportunities in the future if fish passage is restored downstream to Springbrook
Creek. This will not affect listed fish species as no listed fish are currently present
in this area. The altered wetland hydrology may also promote growth of
cottonwoods in areas that are currently too wet, which may have a beneficial
effect to migrating yellow-billed cuckoo due to the improved habitat.
Interrelated and Interdependent Actions
The original consultation identified one interrelated action, the construction of the
Springbrook Wetland and Habitat Mitigation Bank (Springbrook Bank), which
was completed in 2007. The Springbrook Bank was constructed to
compensate for aquatic resource impacts in anticipation of future projects
along the I-405 and SR 167 corridors, including the Direct Connector Project.
There are no additional interrelated or interdependent actions associated with
the current project.
I-405/SR 167 Direct Connector Project Page
23
MINIMIZATION MEASURES
Avoidance and minimization measures are specific measures that will be
incorporated into project construction to reduce potential effects to listed species
or habitats.
Vegetation and Wetlands
x Sensitive areas and vegetation to remain will be delineated with high-
visibility fencing to avoid impacts.
x Clearing and grubbing will be limited to the greatest extent possible to
retain existing vegetation and root structure. In areas where temporary
access is needed, vegetation will not be grubbed, to allow more rapid
recovery of native woody species cover.
x Forested areas will be identified on plan sheets and protected to the
greatest extent possible. Temporary access, staging, and stockpiling will
be limited to upland sites that are already in a disturbed condition.
Water Quality
x A Temporary Erosion and Sediment Control (TESC) plan will be
implemented to minimize water quality impacts during construction.
x Silt curtains, sandbags, and straw wattles, and check dams will be utilized
for instream work associated with fish passage.
x A water quality monitoring plan will be implemented throughout in-water
work to ensure the effectiveness of BMPs.
Fish Exclusion
x Fish exclusion will be conducted with the leadership of a qualified biologist
with appropriate training.
x Non-invasive methods will be employed to exclude fish from in-water work
areas whenever possible. Seine nets and dip nets will be used as a first
choice. Electrofishing will only be used as a last resort.
Mitigation
Mitigation credits will be utilized from the Springbrook Creek Wetland Mitigation
Bank to compensate for approximately 6.8 acres of wetland impacts.
The permanent impact of 0.06 acres (and 520 linear feet) of Rolling Hills Creek
will be mitigated on-site with the re-aligning of the creek and subsequent
restoration. The low-flow channel on the restoration site will be approximately 10
feet wide and 1400 feet long, resulting in a significant increase in open channel
and riparian habitat along Rolling Hills Creek.
I-405/SR 167 Direct Connector Project Page
24
EFFECT DETERMINATIONS
Yellow-Billed Cuckoo
The project may affect yellow-billed cuckoo because:
There is a large forested wetland complex (over 50 acres) including
patches of cottonwood that will be impacted by the project, including the
removal of up to 100 trees across an area of 0.28 acres.
The large tract of forested area including the cottonwood patches has the
potential to provide dispersal or foraging habitat for migrating birds.
Elevated project noise may be generated when yellow-billed cuckoo are
dispersing into northern habitats. If these birds were in the action area,
they could be temporarily disturbed and displaced.
The project is not likely to adversely affect yellow-billed cuckoo because:
Nesting yellow-billed cuckoo have not been documented in Washington or
Oregon for many decades and are not expected within the action area;
and
Yellow-billed cuckoo are sensitive to traffic noise (Goodwin and Shriver
2011), and dispersing/migrating birds would likely avoid the elevated noise
associated with the busy I-405 corridor and the nearby Renton Municipal
Airport.
The loss of 0.28 acres of hardwood forest in a heavily urbanized area
would have insignificant effects on migrating cuckoos.
Oregon Spotted Frog
The project will have no effect on the Oregon spotted frog because:
The project is located in central King County where there are no currently
known sites occupied by Oregon spotted frogs.
The potential presence of the species in the action area is discountable
due to the distance to known historical or occupied sites and the limited
mobility of the species.
I-405/SR 167 Direct Connector Project Page
25
Puget Sound DPS Steelhead
The original BA and BiOp included an effect determination of May affect, likely
to adversely affect the Puget Sound DPS steelhead. The Direct Connector
Project will maintain that determination because there will be 1000 ft2 of new
PGIS along Panther Creek. This will increase stormwater inputs into the creek,
which may provide suitable habitat for steelhead.
Puget Sound Steelhead Proposed Critical Habitat
The project will not destroy or adversely modify proposed steelhead critical
habitat. Should Puget Sound steelhead trout critical habitat be designated
prior to completion of the project, a provisional effect determination for critical
habitat is No Effect because:
The project does not include work in proposed steelhead critical habitat.
The nearest proposed critical habitat is in Springbrook Creek
approximately 2,600 feet downstream of the immediate project area.
Potential turbid water generated during the Rolling Hills Creek culvert
replacement and channel relocation will not affect proposed critical habitat
downstream.
I-405/SR 167 Direct Connector Project Page
26
REFERENCES
Washington State Department of Transportation (WSDOT). 2007. Biological
Assessment: I-405/SR 167 Direct Connector Project. Northwest Region
Design Build Program. June 2007.
NMFS. 2015. National Oceanic and Atmospheric Administration, National
Marine Fisheries Service, Office of Protected Resources. Species under
the Endangered Species Act (ESA). Updated July 2, 2014. Accessed
January 7, 2015: http://www.nmfs.noaa.gov/pr/species/esa/
USFWS. 2015a. United States Fish and Wildlife Service. Threatened and
Endangered Species. Accessed January 7, 2015 at:
http://www.fws.gov/endangered/
USFWS, 2015b. Information Planning and Conservation System (IPaC).
Accessed at:
http://ecos.fws.gov/ipac/on May 4, 2015.
WDFW. 2011. Washington Department of Fish and Wildlife. Priority Habitats
and Species Database. Data published in GIS format for WSDOT on
December 20, 2011. Accessed on January 7, 2015.
WDNR. 2015. Washington Department of Natural Resources. Plant Heritage of
Washington. GIS layers accessed through WSDOT Environmental
Workbench. Accessed on January 7, 2015.
Washington State Department of Transportation (WSDOT). 2015. Biological
Assessment Preparation for Transportation Projects – Advanced Training
Manual. WSDOT Environmental Services, Olympia, Washington. Version
02-2015.
Washington State Department of Transportation (WSDOT). 2015. Wetland and
Stream Assessment Report Addendum: I-405/SR 167 Direct Connector
Project. Northwest Region Design Build Program. January 2015. XL 4282.
Washington State Department of Transportation (WSDOT). 2015. Wetland and
Stream Mitigation Memorandum: I-405/SR 167 Direct Connector Project.
Northwest Region Design Build Program. March 2015. XL 4282.
Washington State Department of Transportation (WSDOT). 2014. 2014
Annual Traffic Report. WSDOT in cooperation with the United States
Department of Transportation Federal Highway Administration.
I-405/SR 167 Direct Connector Project A-1
APPENDIX A – HYDRAULIC SUMMARY
I-405/SR 167 Direct Connector Project A-1
JARPA ATTACHMENT 13
STORMWATER MANAGEMENT CONCEPT FOR
I-405/SR 167 INTERCHANGE - DIRECT CONNECTOR PROJECT
Page 1 of 17
This appendix summarizes preliminary stormwater planning and design for the purposes of
environmental documentation for the I-405/SR 167 Interchange - Direct Connector Project (Project).
Note that the final design will continue to develop these preliminary stormwater management
concepts. The Design-Build Contract will specify performance standards that are based on the
Washington State Department of Transportation (WSDOT) Highway Runoff Manual (HRM)
requirements. This design is one solution that will meet that standard, but this information is subject
to change during final design using equivalent mitigation measures.
Project Watershed
The project scope includes I-405 Corridor improvements from MP 2.32 to MP 3.28, and SR 167
improvements from MP 24.80 to MP 26.26. The Project is located in the lower elevations of the
Lower Green River sub-basin and Black River/Springbrook Creek sub-basin of state Water Resource
Inventory Areas (WRIA) 9 – Green-Duwamish River Watershed. The upper portions of the Green-
Duwamish River and Lake Washington watersheds have undergone relatively little development and
most of the land cover is second-growth forest. The lower portions of these tributary basins, in
contrast, have undergone extensive land use changes in the form of either agriculture or commercial,
urban, and residential development.
The work is entirely within the City limits of Renton, Washington and falls within three tributaries of
Springbrook Creek: Rolling Hills Creek, Thunder Hills Creek; and Panther Creek.
In contrast to the biological assessment and ESA consultation, the Project flow control will be based on
a predevelopment land cover definition following the current HRM. Predevelopment will be forested
land cover condition except where the HRM allows an exemption for discharges to a 2-year floodplain.
In that case, the Project will verify that Minimum Requirement 7 (wetland hydroperiod criterion) is
met.
Runoff treatment design will follow the HRM and also meet the “no net increase” in average annual
pollutant concentrations and loadings for Total Suspended Solids, Total and Dissolved Zinc, and Total
and Dissolved Copper criteria established in the NOAA Fisheries Biological Opinion (BiOp) from the
I-405 Tukwila to Renton Improvement Project (I-5 to SR 169 – Phase 2) Environmental Assessment
effort.
I-405/SR 167 Interchange - Direct Connector Project JARPA Form Attachment 13
STORMWATER MANAGEMENT CONCEPT FOR
I-405/SR 167 INTERCHANGE - DIRECT CONNECTOR PROJECT
Page 2 of 17
Project Drainage Basins
The watershed is divided into two Threshold Discharge Areas (TDAs):
Table 1: WRIA 9 - Green-Duwamish River Watershed, Lower Green River
and Black River/Springbrook Creek Sub-Basins
Threshold
Discharge
Area
Receiving Water Body Sub-Basin Limits Along
I-405 Unless Otherwise Noted
S2.2, S2.3,
& S2.4
Rolling Hills and Thunder Hills Creek that
combine into the SW 19th Street tributary
drainage system to Springbrook Creek
SR-167 to approximately
Renton City Hall and along
SR 167 from I-405 to SE 19th
Street
S2.1 Panther Creek (SW 23rd Street channel)
tributary to Springbrook Creek
Along SR 167 from SE 19th
Street to SE 41st Street
Figure 1: Vicinity Map with TDA Locations (See Figure 2 for Streams)
I-405/SR 167 Interchange - Direct Connector Project JARPA Form Attachment 13
STORMWATER MANAGEMENT CONCEPT FOR
I-405/SR 167 INTERCHANGE - DIRECT CONNECTOR PROJECT
Page 3 of 17
Proposal Overview
The Project will increase the pollutant generating impervious surface area (PGIS) by 7.36 acres,
approximately 19 percent over current conditions. The project will include the following stormwater
facilities:
• Existing stormwater collection and conveyance systems will be modified as required for the
new roadway geometry and as required for stormwater management using equivalent
catchment areas.
• Three new flow control facilities will be constructed (see below for details).
• WSDOT HRM compliant enhanced runoff treatment BMPs will be constructed or modified as
required to meet environmental commitments made in the Environmental Assessment and
ESA Consultation process.
• One culvert under the SR 167 corridor (Mile Post 26.07) will be replaced by a new fish passable
structure (Mile Post 25.93).
• A section of the Lower Rolling Hills Creek will be extended. This work will also provide stream
restoration along the east side of SR 167 between SW 19th Street and the northbound SR 167
to northbound I-405 ramp.
See Attachment 13B for an illustration of the preliminary stormwater facilities.
Flow Control
Infiltration is the preferred flow control best management practice (BMPs), but there are no known
opportunities for infiltration along the project area. Groundwater levels are high along the Renton
valley floor where there are opportunities to site a pond. This was verified by monitoring piezometer
wells at each pond site, so the preliminary design assumes that flow control will be provided by
detention ponds and vaults. Other options may be considered as the design continues.
The preliminary design has reviewed the existing flow control facilities along the I-405 and SR 167
corridors. Few facilities existed before the I-405 Corridor Program improvements. Three facilities
were constructed within the project limit as a result of the I-405, I-5 to SR 169 Stage 1 Widening
Project (Renton Stage 1) and I-405, I-5 to SR 169 Stage 2 Widening & SR 515 Interchange Project
(Renton Stage 2):
• Renton Stage 1, Pond FC S2.1: located in the southwest quadrant of the SR 167 interchange
with I-405
• Renton Stage 2, Talbot Pond: located south of I-405 and to the west of Talbot Road.
• Renton Stage 2, Benson Pond: located on the west side of I-405 to the north of the Benson
Road Bridge crossing.
The preliminary design will maintain these facilities in place without significantly changing their
contributing areas or function.
I-405/SR 167 Interchange - Direct Connector Project JARPA Form Attachment 13
STORMWATER MANAGEMENT CONCEPT FOR
I-405/SR 167 INTERCHANGE - DIRECT CONNECTOR PROJECT
Page 4 of 17
Three new detention facilities will provide the additional flow control needed to mitigate the project.
The following table summarizes the preliminary engineering approach for flow control to mitigate
the effective new impervious area proposed by the project.
There are two pond locations that have contributing areas that are larger than the equivalent
impervious area that will be mitigated by the new detention ponds.
• SE Quad Pond – Is required to mitigate 5.94 acres, but the preliminary design uses the HRM
equivalent area on-site option to allow the full 12.04 acre contributing area to flow through
the pond. A significant portion of the bypass area is pervious surface, so the peak 100 year
flow rate is less than 50% of the peak flow for the impervious area being mitigated.
• Renton Village Pond – Is required to mitigate 2.61 acres (TDA 2.3) plus 1.10 acres (TDA 2.4)
or a total of 3.71 acres. The preliminary design allows the full 6.68 acre contributing area to
flow through the pond with 0.09 acres of impervious area as on-site bypass flows.
The HRM guidance for flow control modeling scenarios with off-site flow and flow-through areas also
includes the “on-site, full area option.” This second option could result in different pond volumes
relative to those reported in Table 2. The final determination of which option will be used is left to
the final design.
I-405/SR 167 Interchange - Direct Connector Project JARPA Form Attachment 13
STORMWATER MANAGEMENT CONCEPT FOR
I-405/SR 167 INTERCHANGE - DIRECT CONNECTOR PROJECT
Page 5 of 17
Table 2: Summary of Flow Control Facilities Proposed in Preliminary Design
Sub-
Basin
Name
Facility
I.D. Milepost
Net New
Impervious
Area (ac)
Catchment
Area (ac)
Facility
Type
Volume
Required
(ac-ft)
Remarks
S2.1
SW 23rd
Det.
Vault
SR 167
25.72 0.29 0.41 Detention
Vault 0.09
New 110’x10’x4.5’ detention vault with open top located just north of SW
23rd Street (P-9) Panther Creek channel. This facility addresses new
impervious area in the Panther Creek Basin which is tributary to Springbrook
Creek.
A large 40 acre Panther Creek wetland complex exists along northbound
SR 167. The proposal verified that the 0.33 acres of roadway widening
crosses the 2-year floodplain and is exempt from flow control. Flow control
is therefore limited to mitigating the widening on the southbound side of SR
167.
S2.2
SE
Quad.
Pond
SR 167
26.23 5.94 12.041 Detention
Pond 2.41
New detention pond that will discharge to the City storm Drainage system in
East Valley Road. Flows combine with Rolling Hills Creek to flow through SW
19th Street drainage system before discharging to Springbrook Creek.
S2.3/
S2.4
Renton
Village
Pond
I-405
2.75 3.712 6.681 Detention
Pond 1.14
New detention pond that will discharge into the I-405 ditch that leads to
Lower Rolling Hills Creek, through Culvert 42 and 44, through Culvert 76,
and the SW 19th Street drainage system to Springbrook Creek.
S2.4 Benson
Pond
I-405
3.00 0.00
Reduces
from 5.28
to 5.21
Detention
Pond 1.93
Modeling the proposed reduced contributing area found that the I-405
Renton Stage 2 Project flow control mitigation is maintained. No
modification is necessary.
Totals 9.94
Note:
1. The conceptual design accommodates a larger impervious area contributing to the pond by following the HRM guidance for flow control modeling scenarios
for off-site flow and flow-through areas.
2. The Renton Village Pond contributing area includes most of the new impervious area in TDA 2.4. See the text for additional detail.
I-405/SR 167 Interchange - Direct Connector Project JARPA Form Attachment 13
STORMWATER MANAGEMENT CONCEPT FOR
I‐405/SR 167 INTERCHANGE ‐ DIRECT CONNECTOR AND EXPRESS TOLL LANE PROJECT
Page 6 of 17
The preliminary design includes new conveyance across the Talbot Road bridge to address the
portion of TDA 2.4 that could not reach the Benson Pond by gravity. WSDOT is adding this minor
flow diversion (transferring TDA 2.4 within the same tributary to the downstream TDA 2.3) to
facilitate the 2002 I‐405 programmatic EIS Record of Decision commitment for full retrofit of
stormwater management where practicable. No watershed or basin diversions are involved, but the
diversion of TDA 2.4 to TDA 2.3 will cause a minor reduction of peak flows in Rolling Hills Creek from
it crossing under I‐405 (west of Talbot Road) to its confluence with the channel from Culvert 48.
Runoff will be routed through the Renton Village Pond and discharged to an I‐405 roadside drainage
ditch that connects to the Rolling Hills Creek tributary at Culvert 48. The downstream Rolling Hills
Creek is protected from increases in peak flow rates, but flows in that roadside drainage ditch may
increase.
Water Quality Treatment
The HRM provides a variety of enhanced runoff treatment best management practices (BMPs) that
focus on removal of sediment and metals. The preliminary design proposes to install media filter
drain (MFD) and compost amended biofiltration swales (CABS) runoff treatment BMPs.
The design criteria for this project go beyond the 2014 HRM guidelines as needed to meet the
environmental commitments made during the I‐405, I‐5 to SR 169 Phase 2, Tukwila to Renton
Improvement Project Endangered Species Act (ESA) consultation with the National Marine Fisheries
Service. The project must demonstrate that there is “no net increase” in average annual pre‐ versus
post‐project loading and concentrations for five indicator pollutants: total suspended solids, total
and dissolved copper, and total and dissolved zinc. This condition was included in the Biological
Opinion for the larger Tukwila to Renton Improvement Project definition which includes the scope of
the subject project. The method for assessing the “no net increase” requirement is based on the
WSDOT Environmental Procedures Manual that was current at the time of the ESA consultation. The
procedure considers runoff volume losses due to infiltration losses inherent with some BMPs. Refer
to Attachment 13a for additional details.
Table 3 summarizes the pollutant generating impervious surfaces (PGIS) and runoff treatment
improvements that were cleared by permits. The baseline condition for the I‐405 Tukwila to Renton
Improvement Project (I‐5 to SR 169 – Phase 2) environmental assessment was the post‐project
condition for the Springbrook Creek basin improvements that were cleared by the I‐405 Renton
Nickel Improvement Project, I‐5 to SR 169, permits. These runoff treatment considerations were
compared with as‐built improvements to determine the level of treatment required for the subject
project.
I-405/SR 167 Interchange - Direct Connector Project JARPA Form Attachment 13
STORMWATER MANAGEMENT CONCEPT FOR
I-405/SR 167 INTERCHANGE - DIRECT CONNECTOR PROJECT
Page 7 of 17
Table 3: Summary of Runoff Treatment Area for Permitted Conditions
in the Springbrook Creek Basin (in Acres)
Permit Condition Untreated
PGIS
New PGIS Treated
PGIS using
non-
infiltrative
BMPs1
Treated
PGIS using
infiltrative
BMPs2
Pre-Renton Nickel Improvement
Project 102.533 - 0.00 8.53
Renton Nickel Improvement Project =
Baseline for Tukwila to Renton
Improvement Project
98.46 9.76 7.57 14.79
Tukwila to Renton Improvement
Project 60.26 38.26 46.20 32.25
Notes:
1. Non-infiltrative BMPs include biofiltration swale and constructed stormwater treatment wetlands
2. Infiltrative BMPs include two BMPs: media filter drain using an estimated volume loss of 62% based on WSDOT data,
and infiltration ponds which are typically design to infiltrate 100% of the runoff.
3. The value noted here has been calculated based on the other numbers in this table to provide a number for
comparison. The actual value in the I-405 Renton Nickel Improvement Project documents was 53.37 acres based on a
smaller project (basin) boundary.
Table 4: Summary of Runoff Treatment Area for As-Built Conditions (in Acres)
I-405 Corridor Project Year
Completed
New PGIS Treated
PGIS using
non-
infiltrative
BMPs1
Treated
PGIS using
infiltrative
BMPs2
Pre-Project Existing Condition 0.00 8.53
I-405 Renton Stage 1 Project 2010 6.33 8.43 0.55
I-405 Renton Stage 2 Project 2011 3.91 4.13 3.45
Totals 10.24 12.56 12.53
Notes:
1. Non-infiltrative BMPs include biofiltration swale, constructed stormwater treatment wetlands, and modified media
filter drain BMPs (likely conservative: no data available)
2. Infiltrative BMPs include media filter drain using an estimated volume loss of 62% based on WSDOT data.
I-405/SR 167 Interchange - Direct Connector Project JARPA Form Attachment 13
STORMWATER MANAGEMENT CONCEPT FOR
I-405/SR 167 INTERCHANGE - DIRECT CONNECTOR PROJECT
Page 8 of 17
Comparing the permitted condition versus as-built condition, the I-405 Renton Stage 1 Project and I-
405 Renton Stage 2 (and SR 515 Interchange) Project improvements slightly exceeded the level of
development that was cleared in the I-405 Renton Nickel Improvement Project permits. The SR 515
interchange improvements were built as the first stage of the Tukwila to Renton Improvement
Project permitted work. The Project will continue that permitted (10.24 acres) work by adding 7.36
acres of new PGIS. The proposed new PGIS would be 7.81 acres greater than the Tukwila to Renton
Improvement Project (9.76 acres) baseline condition. When completed, the Project will have built
approximately 20 percent of the (38.26 acres) development considered during the Tukwila to Renton
Improvement Project ESA consultation.
Pursuant to the “no net increase” commitment, the average annual pre- versus post-project loading
and concentrations were assessed relative to the I-405, I-5 to SR 169 – Phase 2, Tukwila to Renton
Improvements Project baseline used in the ESA consultation.
Table 5: Summary of Pollutant Model Results Based on the
Proposed Project (Percent Reduction)
Parameter TSS Total Zinc Dissolved
Zinc Total Copper Dissolved
Copper
Loading 24 20 15 18 11
Concentration 20 16 11 16 8
Note: Refer to Attachment 13a for additional detail.
Table 6 summarizes the additional new runoff treatment that is proposed in the preliminary design
concept. Final design requirements will follow a performance specification based on a minimum
runoff treatment requirement. Table 5 is based on runoff treatment for 18.0 acres (less than the
indicated 18.49 acres) to leave an allowance for issues that could arise during final design.
The total PGIS treated and the split between infiltrative versus non-infiltrative BMPs may change as
that specification is met within the constraints of the WSDOT HRM. The pre- versus post-project
average annual pollutant loading and concentration calculation will be repeated to verify the final
design.
There are several runoff treatment facilities in place along I-405 and SR-167 corridors. Among them,
two will be replaced due to impacts by widening:
• Northbound SR 167 includes MFD BMPs that were constructed by SR 167/ 15th St. SW to S.
Grady Way Project (OL-2183) based on the project hydraulic report dated January 1996. The
area treated is estimated to be 2.57 acres.
• Southbound I-405, between the Benson Road S. bridge and the southbound off-ramp to
Talbot Road, includes 0.85 acres of PGIS treatment by MFD BMPs based on the Renton Stage
2 As-Built Hydraulic Report (PIN-840505A, 840502E, and 840504A) dated July 2011.
I-405/SR 167 Interchange - Direct Connector Project JARPA Form Attachment 13
STORMWATER MANAGEMENT CONCEPT FOR
I-405/SR 167 INTERCHANGE - DIRECT CONNECTOR PROJECT
Page 9 of 17
Table 6: Summary of New Runoff Treatment Proposed in Preliminary Design
Basin
Name Facility I.D.
SR 167
Milepost
unless noted
PGIS
Catchment
Area (ac)
Facility Type
Facility
Length
Req’d (ft)
S2.2 CABS2.1 26.20 (RT) 6.06 CABS 120
S2.2 MFD1.1E 26.55 (RT) 0.291 MFD 1500
S2.1/
S2.2 MFD1.1 25.80 (RT) 0.61 MFD 125
S2.2 MFD1.3 26.05 (RT) 0.42 MFD 750
S2.2 MFD1.4 26.10 (RT) 0.35 MFD 320
S2.2 MFD1.6 26.20 (RT) 0.002 MFD 240
S2.2 MFD1.9 26.10 (LT) 0.76 MFD 820
S2.2 MFD1.10 26.20 (LT) 0.24 MFD 430
S2.2 MFD1.11 26.06 (LT) 0.65 MFD 905
S2.2 MFD1.15 26.10
(median) 0.40 MFD 900 sf4
S2.2 MFD1.16 26.15 (RT) 0.29 MFD 750 sf4
S2.2 MFD1.17 26.20 (RT) 0.27 MFD 750 sf4
S2.2 MFD1.18 I-405 2.41 (RT) 0.35 MFD 735 sf4
S2.2 MFD2.2 I-405 2.40 (RT) 0.88 MFD 463
S2.2 MFD2.3 I-405 2.45 (RT) 0.06 MFD 75
S2.3 CABS2.2 I-405 2.75 (LT) 5.88 CABS 100
S2.1 MFD2.1 I-405:
2.90 (LT) 1.003 MFD 1410
Water Quality Totals 18.515
Notes:
1. MFD1.1E reports 0.29 acres as new treatment. Additional length is noted to address existing MFD that will
be reconstructed due to the widening.
2. MFD1.6 reports 0.00 acres because it replaces a compost amended vegetated filter strip BMP that will be
impacted by the widening.
3. MFD2.1 reports 1.00 acres as new treatment. Additional length is noted to address existing MFD that will be
reconstructed due to the widening
4. MFD BMPs using a flow spreader (HRM 2014 – MFD Option 5 or 6). The dimension is given as square feet of
media area.
5. The total reported Runoff Treatment is higher that evaluated for the environmental assessment value of
18.00 acres. Given the preliminary status of the design, we are not certain that all of the preliminary
design’s 18.51 acre of runoff treatment can be provided.
I-405/SR 167 Interchange - Direct Connector Project JARPA Form Attachment 13
STORMWATER MANAGEMENT CONCEPT FOR
I-405/SR 167 INTERCHANGE - DIRECT CONNECTOR PROJECT
Page 10 of 17
Conveyance
The subject project will retain much of the existing drainage structures and conveyance systems
within the project area. Closed conveyance systems will be used as the preferred conveyance
method along the I-405 corridor due to the site constraints. Open ditch and sheet flow conveyance
will continue to be the preferred conveyance method along northbound SR 167.
Roadway widening will require new collection structures along the new edge of pavement. These
new structures will connect to the existing drainage systems. Existing conveyance will be modified as
required to satisfy water quality treatment and flow control measures while maintaining existing
flow patterns to each of the receiving water bodies. The preliminary design has only considered
conveyance as it relates to the feasibility of establishing collection areas for runoff treatment and
flow control. Detailed conveyance plans will be produced during the final design. The City of Renton
conveyance systems will be protected from flow increases.
Fish Barriers
The subject project will include a new water crossing structure to address a fish barrier as part of the
project scope. There are two culverts currently on the WDFW fish barrier list:
• Culvert 76 under SR 167 at Mile Post 26.08 is listed as a partial block.
• Culvert 42/44 under I-405 at Mile Post 2.40 is also listed as a partial block
Figure 2: Vicinity Map Showing Culverts and Streams in the Project Area
I-405/SR 167 Interchange - Direct Connector Project JARPA Form Attachment 13
STORMWATER MANAGEMENT CONCEPT FOR
I-405/SR 167 INTERCHANGE - DIRECT CONNECTOR PROJECT
Page 11 of 17
The project widening will provide a fish passable structure at Culvert 76. The details of the new water
crossing are covered in a separate report.
Culvert 42/44 and Culvert 48 are on WSDOT’s list to be addressed by future I-405 improvement
projects.
Attachments:
13a. Pre- versus Post-Project Pollutant Discharge Assessment
13b. Flow Control and Water Quality Treatment Drawings
I-405/SR 167 Interchange - Direct Connector Project JARPA Form Attachment 13
STORMWATER MANAGEMENT CONCEPT FOR
I-405/SR 167 INTERCHANGE - DIRECT CONNECTOR PROJECT
Page 12 of 17
ATTACHMENT 13a
Pre- versus Post-Project Pollutant Discharge Assessment
Introduction
The pre- versus post-Project pollutant loads and concentrations assessment method was developed
in 2005 to support the ESA consultation with the National Marine Fisheries Service. The intent of
this assessment is to apply best available science to understand the potential impacts from the
project. To be consistent with the I-405 Tukwila to Renton Improvement Project (I-5 to SR 169 –
Phase 2) Biological Opinion, the design shall demonstrate that there is “no net increase” in total
suspended solids, total and dissolved copper, and total and dissolved zinc as a result of the I-405, SR
167 Interchange Direct Connector Project (Project).
Approach
The calculations follow the WSDOT Data-FHWA Method from the 2005 WSDOT Environmental
Procedures Manual (EPM). The assessment provides a projection of the relative change of pollutant
loads and concentrations discharged to the Springbrook Creek basin.
The BMP effectiveness data in the EPM uses primarily basic treatment BMPs designed to 1995 HRM
standards. In contrast, the Project will use enhanced treatment BMPs that are sized to current HRM
design standards. While BMPs that are built to new standards are presumed to work more
effectively, insufficient time has passed for such BMPs to be installed or adequately tested. As a
result, little data exists to accurately quantify the effects of projects following the current HRM
runoff treatment BMPs. The pollutant loading estimates that are attached are based on the data
from outdated BMP designs so the calculation likely underestimates the BMP effectiveness.
The WSDOT Data-FHWA Method estimates annual pollutant loads and concentrations based on
highway runoff characterization and BMP effectiveness data collected from the annual WSDOT
National Pollutant Discharge Elimination System (NPDES) Reports dating back to 2002. This data
provides the most accurate state-wide average annual estimate of pollutant load and concentration
data from both treated and untreated highway surfaces in Washington.
The results generated by this method provide:
• A table for each sub-basin showing,
o the amount of existing acres of highway surface, and
o the amount of acres of future highway surface that would exist as a result of the
project (i.e., net new acres). The table also includes the total number of treated,
infiltrated, and untreated acres in each of the sub-basins.
• The number of acres of untreated surface is multiplied by the annual pollutant load values
for each pollutant.
• The number of acres of treated surface is multiplied by the annual pollutant load value,
which is based on the mean BMP pollutant removal effectiveness.
• The annual pollutant loads from the treated and untreated surfaces are added together to
generate a total pollutant load in pounds per year.
I-405/SR 167 Interchange - Direct Connector Project JARPA Form Attachment 13
STORMWATER MANAGEMENT CONCEPT FOR
I-405/SR 167 INTERCHANGE - DIRECT CONNECTOR PROJECT
Page 13 of 17
• The results of the analysis provide a relative comparison of the annual loads for each
pollutant from each sub-basin and the entire project.
WSDOT EPM methods for evaluating annual pollutant loads produce general estimates of annual
pollutant loads to compare project alternatives in the NEPA/SEPA processes. Pollutant
concentrations in stormwater runoff are highly variable as a result of variables including:
1) the amount of discharge,
2) the size of the receiving water body,
3) the water chemistry (e.g., hardness) and background concentrations of pollutants of concern
in the receiving water,
4) antecedent dry periods,
5) the nature (e.g., intensity, duration) of the storm event,
6) the variability in BMP removal effectiveness, and
7) amounts of organic debris and sediment within the runoff.
During the I-405 Tukwila to Renton Improvement Project ESA consultation, National Marine Fisheries
Service requested that the model consider incidental runoff volume loss associated with the MFD
BMPs. WSDOT and the National Marine Fisheries Service agreed that the monitoring data was
conclusive to validate a model assumption that 62 percent of the highway runoff would infiltrate
though the soil below the media zone. All other types of runoff treatment BMPs are assumed to be
non-infiltrating. The model input calculates an equivalent basin area being “infiltrated” versus
“treated.” Thus the model accounts for the pollutant load reductions that would result from
infiltration losses both in pre- and post-project conditions.
Conclusions
Key points related to drawing conclusions from this approach:
• The assessment provides an average based on samples collected to date. There is variability
between sites and BMPs. Defensible confidence limits cannot be set until adequate
enhanced treatment BMPs are tested at a large number of sites.
• Although we generate an analysis with this approach, there is insufficient existing data to
make an accurate evaluation of BMP effectiveness, receiving water quality, dilution factors,
or adverse impacts to fish.
The proposed enhanced runoff treatment BMPs are sized to handle the runoff volumes generated
during the wet season when pollutant concentrations are expected to be at their lowest due to
dilution. Runoff treatment BMPs, such as constructed stormwater treatment ponds that promote
evapotranspiration, may not discharge during the critical summer season for fish species.
The following calculations are provided to document that the preliminary design meets the intent of
the environmental commitment for “no net increase” in pollutant loads or concentrations as a result
of the Project. The final design contract will require that the final design use the same method to
demonstrate a “no net increase” in average annual pollutant loads or concentrations.
I-405/SR 167 Interchange - Direct Connector Project JARPA Form Attachment 13
DATA ENTRY TO CHECK POST-PROJECT VERSUS ESA CONSULTATION BASELINE Assumes MFD Infiltration = 62%Springbrook Baseline Definition for BOBasinPRE-NICKEL EXISTING CONDITIONUntreatedOther BMPsMFDPRE-PROJECT - Permitted Nickel ImprovementsTotal7.57 14.79Existing treated impervious surface with discharge to waterbody (acres)13.19Treated- 7.57 5.62Existing impervious surface infiltrated (acres)9.17Infiltrated - - 9.17Existing untreated impervious surface (acres)98.46Untreated 98.46Total existing impervious surface (acres)120.82UntreatedOther BMPsMFDRenton Nickel Permit NEW RETROFITTotal- - 12.60Existing impervious surface retrofitted for treatment with discharge to waterbody (acres)4.79Treated- - 4.79Existing impervious surface retrofitted for infiltration (acres)7.81Infiltrated - - 7.81Renton Nickel Permit NEW IMPERVIOUSTotal- 7.57 2.19New treated impervious surface with discharge to waterbody (acres)9.76Treated- 7.57 2.19New impervious surface infiltrated (acres)0.00Infiltrated - - 0.00New untreated impervious surface (acres)0.00Untreated - - Total new impervious surface (acres)9.76Permit Totals:7.57 14.79Permitted Renton Nickle Treatement - TRIP BASELINESprgbrkExisting treated impervious surface with discharge to waterbody (acres) 27.74Existing impervious surface infiltrated (acres) 16.98Existing untreated impervious surface (acres) 98.46UntreatedOther BMPsMFDSR 515 Impr + PROJECT NEW RETROFITTotal- 9.12 3.80Existing impervious surface retrofitted for treatment with discharge to waterbody (acres)10.56Treated- 9.12 1.44Existing impervious surface retrofitted for infiltration (acres)2.36Infiltrated - - 2.36SR 515 Impr + PROJECT NEW IMPERVIOUSTotal- 7.81 0.00New treated impervious surface with discharge to waterbody (acres)7.81Treated- 7.81 0.00New impervious surface infiltrated (acres)0.00Infiltrated - - 0.00New untreated impervious surface (acres)0.00Untreated - - Total new impervious surface (acres)7.81Proj. Totals:16.93 3.80POST PROJECT TOTALSTotal impervious surface area untreated post-project (acres)72.94LEGENDTotal impervious surface area treated post-project with discharge to waterbody (acres)46.11Other BMPsTotal impervious surface area infiltrated (acres)19.34BA Total PGIS138.39MFD = Media Filter DrainSpringbrookIncludes "combined stormwater treatment wetland/detention", "Bioswales", "wetpool", and MMFD BMPs3/10/2015 AssessmentAttachment 13A M:\Eng\167-DC\Drn\JARPADoc\JARPA_Attach13a_CheckingBOBaseline_Mar6.xlsxDC ENTRY
I-405/SR 167 Interchange - Direct Connector Project JARPA Form Attachment 13
LOAD EFFECTS - POST-PROJECT VERSUS ESA CONSULTATION BASELINETOTAL DISSOLVED TOTAL DISSOLVEDTSSZINC ZINC COPPER COPPERMean annual load from untreated surfaces (lbs/acre)565 1.10.40.2 0.053Mean annual load from treated surfaces (lbs/acre)45 0.28 0.2 0.065 0.035TOTAL DISSOLVED TOTAL DISSOLVEDTSSZINC ZINC COPPER COPPERSpringbrook Creek BasinAnnual effluent load from existing impervious surfaces prior to project (lbs)56,878.12 116.07 44.93 21.49 6.19Annual effluent load from new and existing impervious surfaces after project (lbs)43,286.15 93.15 38.40 17.59 5.48NET CHANGE (lbs)-13,591.97 -22.93 -6.53 -3.91 -0.71NET PERCENT CHANGE-24% -20% -15% -18% -11%LOAD RATESPROJECT TOTAL3/10/2015 AssessmentAttachment 13A M:\Eng\167-DC\Drn\JARPADoc\JARPA_Attach13a_CheckingBOBaseline_Mar6.xlsxDC LOAD
I-405/SR 167 Interchange - Direct Connector Project JARPA Form Attachment 13
CONCENTRATION EFFECTS - POST-PROJECT VERSUS ESA CONSULTATION BASELINETOTALDISSOLVEDTOTALDISSOLVEDTSS ZINC ZINC COPPER COPPER(mg/L)(ug/L) (ug/L) (ug/L) (ug/L)Expected pollutant concentrations for UNTREATED runoff192 350 110 59 14Expected pollutant concentrations for TREATED runoff 14 67 44.8 12 7.8TOTALDISSOLVEDTOTALDISSOLVEDTSS ZINC ZINC COPPER COPPER(mg/L)(ug/L) (ug/L) (ug/L) (ug/L)Springbrook Creek BasinPollutant concentation for runoff PRE-project152.88 287.80 95.67 48.67 12.64Pollutant concentation for runoff POST-project123.06 240.39 84.75 40.80 11.60NET CHANGE-29.82 -47.41 -10.92 -7.87 -1.04NET PERCENT CHANGE-20% -16% -11% -16% -8%PROJECT TOTAL3/10/2015 AssessmentAttachment 13A M:\Eng\167-DC\Drn\JARPADoc\JARPA_Attach13a_CheckingBOBaseline_Mar6.xlsxDC CONC
I-405/SR 167 Interchange - Direct Connector Project JARPA Form Attachment 13
STORMWATER MANAGEMENT CONCEPT FOR
I-405/SR 167 INTERCHANGE - DIRECT CONNECTOR PROJECT
Page 17 of 17
ATTACHMENT 13b
Flow Control and Water Quality Treatment Drawings
I-405/SR 167 Interchange - Direct Connector Project JARPA Form Attachment 13
???P
P PPTREES AND BRUSHTREES AND BRUSHTREES AND BRUSHCCCCCMBUOBJUOBJUOBJ
UOBJUOBJUOBJUOBJUOBJUOBJUOBJUOBJUOBJ UOBJUOBJUOBJ UOBJ UOBJ
UOBJUOBJ??????TUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUPPPPPPP
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC???CVUUUUUUUUU UPPP15'
12'
13'
13'
12'
12'
12'12'
12'
12'
11'
12'
12'
12'
8'
13'
13'
13'
12'
10'
12'
13'
12'
12'15'8'
10'
12'12'
12'
12'
10'SW 19TH STSW 27TH ST HOTEL
HILTON GARDEN
EAST VALLEY RD
EAST VALLEY RD
LANDING
LARKSPUR
STORAGE
SHURGARD
E167 LINE
E167 LINE
E167A LINE
E167A LINE
MP 25.45
MP 25.50
MP 25.55
MP 25.60
MP 25.65
MP 25.70
MP 25.75
MP 25.80
MP 25.85
MP 25.90
MP 25.95 MP 26.00
SCALE IN FEET
0
INTERSTATE
405 Project Team
Washington State
Department of Transportation
SHEET
OF
SHEETS
01
100 200
WATER QUALITY TREATMENT
FLOW CONTROL AND 05SW 23RD STREET CHANNEL(CULVERT 72)
PANTHER CREEK
(CULVERT 76)
ROLLING HILLS CREEKSW 19TH STCATCHMENT AREA = 2.45 ACRE PGIS
LENGTH = 2170 LF
MFD 1.1E
CATCHMENT AREA = 0.61 ACRE PGIS
LENGTH = 125 LF
MFD 1.1
CATCHMENT AREA = 0.41 AC
NET NEW IMPERVIOUS AREA = 0.29 AC
REQ'D VOLUME = 0.09 AC-FT
DIMENSIONS = 110'(L) x 10'(W) x 4.5'(D)
SW 23RD ST VICINITY DETENTION OPEN VAULT
ATTACHMENT 13B
I-405/ SR 167 INTERCHANGE
DIRECT CONNECTOR
SR 167
I-405/SR 167 Interchange - Direct Connector Project JARPA Form Attachment 13
???????PPTREES AND BRUSHTREES AND BRUSHTREES AND BRUSH?44.716
43.286
41.458
41.708
37.752
40.493
37.684
35.957
35.127
33.120
CB1FLCB1FLCB2FLCB3FLCBAFL
CBAFL
CBBFL
CBCFL
29.428
42.112
46.012
58.455
28.522
52.889
66.554
28.62240.959
69.411
35.769
51.404
43.322
51.404
70.649
76.829
46.900
45.515
76.398
54.994
73.936
56.639
48.09563.723
37.381
41.294
24in CMP OUTFALL HAS BAFFLE
36in CMP
12in CMP
??CVCVC
VUOBJUOBJ?????CVUUUUUU???MP 26.00 MP 26.05 MP 26.10 MP 26.15 MP 26.20 MP 26.25
INTERSTATE
405 Project Team
Washington State
Department of Transportation
SHEET
OF
SHEETS
SCALE IN FEET
0
02
WATER QUALITY TREATMENT
FLOW CONTROL AND
50 100
05
TO REMAIN
EXISTING POND
CATCHMENT AREA = 0.29 ACRE PGIS
DIMENSIONS = 75'(L) x 10'(W)
MFD1.16 (TYPE 6)
CATCHMENT AREA = 0.40 ACRE PGIS
DIMENSIONS = 90'(L) x 10'(W)
MFD1.15 (TYPE 6)
CATCHMENT AREA = 0.27 ACRE PGIS
DIMENSIONS = 75'(L) x 10'(W)
MFD1.17 (TYPE 5)
CATCHMENT AREA = 0.24 ACRE PGIS
LENGTH = 430 LF
MFD1.10
CATCHMENT AREA = 0.65 ACRE PGIS
LENGTH = 905 LF
MFD1.11
CATCHMENT AREA = 0.76 ACRE PGIS
LENGTH = 820 LF
MFD1.9
CATCHMENT AREA = 0.35 ACRE PGIS
LENGTH = 320 LF
MFD1.4
CATCHMENT AREA = 0.35 ACRE PGIS
LENGTH = 240 LF
MFD1.6
CATCHMENT AREA = 0.42 ACRE PGIS
LENGTH = 750 LF
MFD1.3
SEE SHEET 3
SE QUADRANT POND
SEE SHEET 3
BIOSWALE - CABS 2.1
CHANNEL RELOCATION
ROLLING HILLS CREEK
TO CITY DRAINAGE SYSTEM
STORM DRAIN CONNECTION
CULVERT 76 REUSED FOR
ATTACHMENT 13B
I-405/ SR 167 INTERCHANGE
DIRECT CONNECTOR
SR167
I-405/SR 167 Interchange - Direct Connector Project JARPA Form Attachment 13
?
?P?
44.716
43.286
41.458
41.708
37.752
40.493
37.684
35.957
35.127
33.120
CB1FL
CB1FLCB2FLCB3FL
CBAFL
CBAFLCBBFLCBCFL
29.428
42.112
46.012
58.455
28.522
52.889
66.554
28.622
40.959
69.411
35.769
51.404
43.322
51.404
70.649
76.829
46.900
45.515
76.398
54.994
73.936
56.639
48.095
63.723
37.381
41.294
24in CMP OUTFALL HAS BAFFLE
36in CMP 12in CMP MBMBMBMBMBMBMBMBMBMBMBMBMBMBMB?
?
?
?
?
?
???
?
?
?
??
?
?
?
?
?
?
?CVCVCVCV
U
UUUU
U
U
U
U
U
U
U UU
UUUU
P PPPP
PPPPPP?
U
U PP PPP
P P
P
UOBJ
?
??
??
?
?
?
?
?
?
?
?
?
?
?
?STTS
TT
MP 2.30
MP 2.35
MP 2.40
MP 2.45
MP 2.50
MP 2.55
MP 26.20MP 26.25MP 26.30SCALE IN FEET
0 50 100
INTERSTATE
405 Project Team
Washington State
Department of Transportation
SHEET
WATER QUALITY TREATMENT
FLOW CONTROL AND 05
OF
03
SHEETS
TO BE ABANDONED
EXISTING CAVFS
CATCHMENT AREA = 0.35 ACRE PGIS
DIMENSIONS = 75'(L) x 10'(W)
MFD1.18 (TYPE 6)
CATCHMENT AREA = 6.06 ACRE PGIS
DIMENSIONS = 110'(L) x 7'(W); 3:1 (SIDE SLOPE)
BIOSWALE - CABS 2.1
CATCHMENT AREA = 12.04 ACRE
NET NEW IMPERVIOUS = 5.94 ACRE
REQ'D VOLUME = 2.41 AC-FT
DIMENSIONS = 9000 SF BOTTOM x 5' DEEP
SE QUADRANT DETENTION POND FC 2.2
CATCHMENT AREA = 0.88 ACRE PGIS
LENGTH = 463 LF
MFD2.2
CATCHMENT AREA = 0.06 ACRE PGIS
LENGTH = 75 LF
MFD2.3
ATTACHMENT 13B
DIRECT CONNECTOR
I-405/ SR 167 INTERCHANGE
NB I-405
SB I-405
SEE SHEET 2
MFD 1.17
I-405/SR 167 Interchange - Direct Connector Project JARPA Form Attachment 13
C
C CMBMB
MB?
?
?
?
?
?
?
?
?
??
?
?
?
??
?
CV
CV
U
UU
U
UU
U
U
U
U
U
U
U
U
U
U
U
U
U
UPP UOBJ
UOBJ
UOBJ
UOBJ
UOBJ
UOBJ
?
?
?
?
?
?
U
U
U
U
U
U
U
U
PP
PPPPPPPP
P PPPPP
P P PU
UU
U
UU
UU
U
P
PP P
P
P
UOBJ
UOBJ
UOBJ
UOBJ
?
?
?
?
T
STTSTTSTT
42" CONC
42" CONC
30" CONC72" CONC
60" CONC 60" CONC48" CONC 72" CONC
CULVERT C48CULVERT C4942" CONCCULVERT C4942" CONCMP 2.55
MP 2.60
MP 2.65
MP 2.70
MP 2.75
MP 2.80
MP 2.85
INTERSTATE
405 Project Team
Washington State
Department of Transportation
SHEET
SCALE IN FEET
0
WATER QUALITY TREATMENT
FLOW CONTROL AND
50 100
05
OF
04
SHEETS
CATCHMENT AREA = 6.68 ACRE
HRM "50% RULE" FOR FLOW THROUGH)
(INCL. ADDITIONAL MITIGATION PER
NET NEW IMPERVIOUS = 3.71 ACRE
REQ'D VOLUME = 1.14 AC-FT
DIMENSIONS = 9300 SF BOTTOM x 4.8' DEEP
RENTON VILLAGE POND - FC 2.3/2.4
CATCHMENT AREA = 5.88 ACRE PGIS
DIMENSIONS = 95'(L) x 20' (W); 2:1 (SIDE SLOPE)
BIOSWALE - CABS 2.2
ATTACHMENT 13B
DIRECT CONNECTOR
I-405/ SR 167 INTERCHANGE
SB I-405
NB I-405
TALBOT RD SSMITHERS AVE SMORRIS AVE SWHITWORTH AVE SSHATTUCK AVE SS RENTON VILLAGE PL
I-405/SR 167 Interchange - Direct Connector Project JARPA Form Attachment 13
C
U
O
BJ
U
O
BJ
U
O
BJ
UOBJ
UOBJ
UOBJ
?
?
?
??
?
?
?UU
U
U
U
U
U
U
P
P
STTSTTSTTM
P 2.90MP
2
.95
MP 3.00
MP 3.05
MP 3.10
MP 3.15
SCALE IN FEET
0 50 100
INTERSTATE
405 Project Team
Washington State
Department of Transportation
SHEET
OF
SHEETS
CATCHMENT AREA = 1.98 ACRE
LENGTH = 1410 LF
MFD2.1
WATER QUALITY TREATMENT
FLOW CONTROL AND
05
05
(TO REMAIN)
BENSON POND
ATTACHMENT 13B
I-405/ SR 167 INTERCHANGE
DIRECT CONNECTOR
BENSON ROAD
N
B
I-405
SB
I-40
5
SB I-405 TO TALBOT ROAD RAMP
I-405/SR 167 Interchange - Direct Connector Project JARPA Form Attachment 13
APPENDIX B – ROLLING HILLS CREEK RESTORATION PLAN
I-405/SR 167 Direct Connector Project B-1
APPENDIX C – EXISTING CONDITIONS PLAN SHEETS
I-405/SR 167 Direct Connector Project C-1