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Draft Phase 1 Methods and Data Report Cedar River Gravel Study Prepared for: U.S. Army Corps of Engineers Seattle District Seattle, Washington Prepared by: MJones &Stokes April 2002 V t DEPARTMENT OF THE ARMY SEATTLE DISTRICT, CORPS OF ENGINEERS P.O. BOX 3755 SEATTLE, WASHINGTON 98124-2255 REPLY TO ATTENTION OF CENWS-PM-PL-ER Mr. Gary Schimek City of Renton Renton City Hall- 51h Floor 1055 South Grady Way Renton, Washington 98055 RECEIVED JUL - 3 2002 CITY OF RENTON UTILITY SYSTEMS ul-NIME11 Subject: Request for Comment on "Cedar River Gravel Study- Phase II Draft Report". Dear Gary: I am pleased to submit for review the above titled report. The Phase II report is a companion volume to the Phase I Methods and Data Report by Jones and Stokes. Please refer to the Phase I report for maps and the supporting data. The Cedar River Gravel Study was conducted to obtain additional information on the condition and location of spawning gravels within the Cedar River for consideration during restoration planning under the Lake Washington GI Ecosystem Restoration Project. Please provide comments to me by July 16, 2002 in order to allow adequate time for inclusion. I will consolidate and forward all comments to Mr. Mike Wolonek (Jones & Stokes) and Mrs. Susan Perkins (Perkins Geosciences) for consideration in the final report. If you have any questions please call me at telephone (206) 764-6174. Enclosure cc: Larry Fisher-WDFW Keith Kurko- City of Seattle Deb Lester- King County Gary Shimeck- City of Renton Scott Brewer- King County Sincerely, 4�� 9 n Biologist- USACE N Cedar River Gravel Study Draft Phase 2 Report prepared by Perkins Geosciences 7731 14"' Avenue NW Seattle, WA 98117 (206) 783-3991 with Harper Houf Righellis, Inc. 9324 Eagle Ridge Drive Las Vegas, NV 89134 for U.S. Army Corps of Engineers Seattle District and Jones & Stokes Bellevue, Washington June 2002 TABLE OF CONTENTS 1. INTRODUCTION.......................................................................................................1 2. GRAVEL SUPPLY....................................................................................................2 2.1 Gravel Supply Methods......................................................................................... 2 2.2 Gravel Supply Results.......................................................................................... 4 2.3 Historical Context of Sediment Supply.................................................................. 6 3. EFFECTS OF MORPHOLOGY AND HYDRAULICS ON GRAVEL DISTRIBUTION...........................................................................................................13 3.1 Methods..............................................................................................................13 Hydraulic Analysis Methodology.......................................................................... 13 Segment -Level Analysis Approach........................................................................14 Cross-section analysis approach............................................................................15 3.2 Results.................................................................................................................17 Segment -Level Findings........................................................................................17 Cross -Section Level Findings................................................................................ 27 4. DISCUSSION...........................................................................................................39 4.1 Effect of Landsburg Dam on Gravel Transport .................................................... 39 Sediment Transport Through the Dam................................................................... 39 GeomorphicEvidence........................................................................................... 39 HydraulicCalculations.......................................................................................... 40 4.2 Factors Associated with Spawning Gravel Abundance ......................................... 42 Geomorphic and Hydraulic Factors ......... :............................................................. 42 HumanModifications............................................................................................ 42 4.3 Utilization of Gravels by Salmonids.................................................................... 46 5. RESTORATION NEEDS AND STRATEGIES........................................................ 47 5.1 Recommended Strategies.....................................................................................47 Levee Removal or Setback.................................................................................... 47 FloodplainExcavation........................................................................................... 48 5.2 Restoration Strategies of Limited Usefulness....................................................... 48 GravelAugmentation............................................................................................ 48 Control of Fine Sediment Sources......................................................................... 49 Artificial Spawning Channels................................................................................ 49 HEC-6 Sediment Modeling................................................................................... 50 6. CONCLUSIONS....................................................................................................... 50 7. REFERENCES......................................................................................................... 52 LIST OF FIGURES Figure 1. Cedar River Basin Location Map...................................................................... 7 Figure 2. Sources of Gravel to the Cedar River Downstream of Landsburg Dam ........... 11 Figure 3. Estimated Gravel Supply to the Cedar River Study Segments .........................12 Figure 4. Lower Cedar River Profile Showing Study Segments ..................................... 21 Figure 5. Upper Cedar River Profile.............................................................................. 22 Figure 6. Gradient -Confinement Index by River Segment ............................................. 23 Draft Phase 2 Report — Cedar River Gravel Study 611712002 Figure 7. Extent of Unarmored Cliffs by River Segment ................................................ 23 Figure 8. Extent of Armored Banks by River Segment .................................................. 24 Figure 9. Available Spawning Area by River Segment .................................................. 24 Figure 10. Gradient and Available Spawning Area ........................................................ 25 Figure 11. Gradient -Confinement Index and Available Spawning Area ......................... 25 Figure 12. Shear Stress and Available Spawning Area ................................................... 26 Figure 13. Shear Stress and Energy. Gradient................................................................. 26 Figure 14. Armored Banks and Available Spawning Area ............................................. 27 Figure 15. Surface Median Diameter Measured in Pebble Counts on the Riverbed........ 31 Figure 16. Comparison of Subsurface Samples from Gravel Bars Versus River Channel. .............................................................................................................................. 32 Figure 17. Surface Sediment Size and Available Spawning Area ................................... 32 Figure 18. Relationship Between Median Sediment Size and Gradient .......................... 33 Figure 19. Spawning Area and Local Bed Slope............................................................ 34 Figure 20. Effect of 10-year Flood Confinement Ratio on Surface Grain Size ............... 34 Figure 21. Gradient -Confinement Index and Surface Sediment Size for 10-Year Flood. 35 Figure 22. Shear Stress and Sediment Size for Cross -Sections Meeting Uniform Flow Criteria.................................................................................................................. 36 Figure 23. Predicted Median Grain Size that Would be Mobile During a 1.2-Year Flood ................................................................................................. 37 Figure 24. Excess Shear Stress Ratio During Bankfull Flood for Gravel with a Median Surface Diameter of 40 mm................................................................................... 38 Figure 25. Shear Stress Profile Upstream from Landsburg Dam, from HEC-RAS model. .............................................................................................................................. 44 LIST OF TABLES Table 1. Soil Creep Calculation....................................................................................... 8 Table 2. Sediment Budget for Cedar River above Landsburg........................................... 8 Table 3. Gravel Supply from Tributary Creeks Below Landsburg.................................... 9 Table 5. Location, Flood Confinement and Average Gradient of Cedar River Study Segments............................................................................................................... 20 Table 6. Factors that Limit Amount of Spawning -Sized Gravels on the Cedar River.... 51 LIST OF APPENDICES A. Segment Data Used for Analysis B. Peak Flow Rates Tabulation C. Cross -Section Data and Calculated Parameters D. Proportion of Surface Sediment Samples in Size Range Preferred for Spawning on the Cedar River Draft Phase 2 Report —Cedar River Gravel Study 611712002 1. INTRODUCTION The team of Jones & Stokes, Perkins Geosciences, and Harper, Houf, & Righellis has evaluated the current conditions of spawning gravel in the Cedar River from upstream of the Landsburg diversion dam to Lake Washington. Cooperating agencies include Seattle Public Utilities, the City of Renton, and King County Department of Natural Resources. The study assessed the quality and distribution of spawning gravel with respect to the hydraulic characteristics of the river. These sediment -hydraulic relationships were then used to determine whether lack of gravel in certain reaches is caused by naturally occurring factors or human changes to channel morphology. The findings will be used to identify and implement restoration needs for the river. The Washington Department of Fisheries (now WA Dept of Fish & Wildlife) conducted a survey of available sockeye spawning gravel habitat and distribution in the late 1960s. These data serve as the basis for the current sockeye escapement goal of 300,000 fish to the Cedar River. This survey was a primarily a visual survey, with minimal bed sampling and was based on surveyor's expertise in identification of suitable sockeye spawning habitat. It is not possible to replicate the study. Since the 1960s several observations of available spawning gravel on the Cedar River have been made. These observations have led researchers and fisheries managers to suggest that current spawning gravels may be less abundant and/or less suitable than the historical condition. Conversely, little research has been conducted to quantify whether current gravels present in the river represent an adequate volume or composition to support long-term salmonid spawning. The Lake Washington GI project, a multi -agency project led by the U.S. Army Corps of Engineers, King County, City of Seattle and local salmon recovery groups, initiated a study to help evaluate whether current Cedar River gravel conditions are capable of adequately sustaining long-term salmonid spawning conditions. The project was implemented in two phases, with an optional third phase dependent on Phase 2 recommendations. Phase 1 activities included data collection and a literature review of current and historic research related to spawning areas and gravel characteristics on the Cedar River. Data collection included surveys of additional cross sections and surface/subsurface bed material distributions; assessment of fine sediment influences on spawning success and delineation of river segments based on gradient and confinement. The Phase 1 report by Jones and Stokes (2002) documented methods involved in data collection and summarized all data and information compiled for analysis under Phase 2. This report describes the methods and results of the Phase 2 analysis, in which the Phase 1 data were evaluated to determine whetl.er and where a "gravel problem" presently exists along the Cedar River. Phase 1 cross sections were combined with existing cross sections from the King County and City of Renton HEC-RAS flood models to calculate the scour potential of various discharges at selected cross sections which reflect a range Draft Phase 2 Report —Cedar River Grm,el Study 611712002 of gradient, confinement and management scenarios. Incipient motion particle size was calculated at these cross sections to determine the flows necessary to initiate the downstream movement of gravel. A sediment budget of the current gravel supply was developed. The impact of the Landsburg diversion on the size and quantity of sediments transported along the river was assessed. The findings were used to determine whether spawning gravel supplies in certain reaches are limited as a result of channel modifications (levees, riparian management, flow regulation) and to identify potential restoration opportunities. This Phase 2 report is a companion volume to the Phase I Methods and Data Report by Jones and Stokes, which contains a 16-map set showing the locations of river segments and sample sites. The Phase 2 report is organized as follows: After this introduction, we present the methods and findings of the gravel supply analysis. The next section contains the methods and findings on the effects of morphology and hydraulics on gravel distribution. This is followed by a discussion of the findings, recommendations, and conclusions. A series of Appendices contain tables of data and calculated parameters used for the phase 2 analysis. 2. GRAVEL SUPPLY The Cedar River receives its gravel supply from only 110 square miles of its watershed below the Chester Morse reservoir (Figure 1). Gravel from the 78 square mile upper watershed is currently trapped within the Chester Morse reservoir. Before the reservoir was built, there was a large lake in that location that trapped gravel historically (King County, 1993). The mountainous, forested watershed between Chester Morse Lake and Landsburg supplies gravel to the river from landslides and other soil erosion processes. The small diversion dam at Landsburg impounds sediment during low flows. During the medium to larger flows at which gravel transport takes place, the Taintor gates are opened and the sediment sluices through (Inter-Fluve, 2000, King County, 1993). The effect of the Landsburg impoundment on sediment transport is discussed further in Section 4.1. Below Landsburg the river receives a significant amount of gravel from eroding bluffs as well as several small tributary streams. This chapter quantifies the rates of supply from these sources to the Cedar River. 2.1 Gravel Supply Methods Sediment supply for the 44 square mile watershed between Landsburg and Chester Morse Reservoir was calculated using a sediment budget approach. The main sources of coarse sediment are landslides and soil creep. Because this study was only concerned with gravel sediment, fine sediment from road erosion was not considered. An existing landslide inventory (Foster Wheeler, 1995b) based on 1989 and 1991 aerial photographs, Draft Phase 2 Report — Cedar River Gravel Stud}, 611712002 2 provided landslide number and surface area, geologic substrate, and approximate landslide age. A list of landslides that have occurred since 1990 was provided by Dave Beedle (SPU, 2002). Low and high volume estimates were made using a likely range of landslide depths and proportion of gravel (based on geologic type). The resultant landslide volume was divided by 28 years (the age of the oldest landslide in the inventory) to obtain an average annual rate of gravel supply to the Cedar River and its tributaries. As the landslide inventory did not include small landslides in the deep inner gorges, which are typically not visible on aerial photographs, we made a supplemental estimate of inner gorge landslide erosion based on mapped inner gorge landslide hazard zones (Foster Wheeler 1995a). The length of inner gorge landslide zone was multiplied by 50 cy/yr to 70 cy/yr, based on estimated erosion rates for the inner gorge of the South Fork Tolt River (Parametrix, 2001). Soil creep rates were estimated using standard parameters and the standard procedure for Washington State watershed analysis (Washington FPB, 1995), as shown in Table 1. The results of the sediment budget were checked by estimating bedload as a percent of suspended sediment yield. Bedload sediment moves along the stream bed by rolling, sliding, or making short jumps. It is composed primarily of gravel but includes some coarse sand. Suspended sediment yields were measured in the 1960s in the Snoqualmie watershed which lies adjacent to the north edge of the Cedar River watershed. Suspended sediment loads in the Snoqualmie watershed ranged from about 200 to 1000 tons/sq mi/yr (Nelson, 1971). We selected a rate of 500 tons/sq mi/yr, in the mid- to lower range, because the Cedar River watershed has not been intensively logged for several decades, and much of it not since the 1930s. The 500 tons/sq mi/yr rate also agrees fairly closely with the 420 tons/sq mi/yr rate estimated for the nearby Green River based on sedimentation rates in Howard Hanson Reservoir (Perkins, 1999). Since bedload in steep streams like the Cedar River is typically on the order of about 10% of suspended sediment yield (Vanoni, 1975; King County, 1993), the selected rate was multiplied by basin area and by 10% to obtain the estimated bedload sediment yield. Only a few of the numerous tributary creeks below Landsburg deliver gravel to the Cedar River. The remaining creeks deposit their gravel in alluvial fans at the toe of the valley wall and only sand and silt reaches the river (King County, 1993). For the creeks that do deliver sediment, we selected an appropriate sediment yield from Nelson (1971) using information from the 1993 study on severity of erosion in each tributary basin. The selected suspended sediment yield was mrltiplied by basin area and 10% to obtain average annual bedload yield. The location and sediment size of eroding river bluffs below Landsburg were recorded during a float trip down the river for project reconnaissance in summer 2001. The rate of cliff retreat was determined from recent and historic aerial photographs by measuring the distance from a fixed point to the river bank in each photograph. In most cases we used the 1936 aerial photographs, which had a large scale and good resolution. In one case a more recent aerial photograph was used because the river had not begun to erode the cliff Draft Phase 2 Report — Cedar Rimer Gravel Study 611712002 1936. The scale of each aerial photograph was determined by measuring reference points shown on a map. The accuracy of each measurement was noted so that the possible error could be determined. The height and length of the eroding cliffs were measured from 2-ft contour interval topographic maps. These dimensions were multiplied by the retreat rate and percentage of gravel to obtain an average gravel recruitment rate for each cliff. Two areas of the lower Cedar River have a significant amount of gravel supplied by infrequent landslides. Major landslides in these reaches occurred two or three times over a 70-year time period based on interpretation of aerial photographs. The estimated landslide volumes were divided by 70 years to obtain an average sediment delivery rate. However, it must be recognized that landslide sediment does not get metered into the river on an annual basis. Instead, large deposits of thousands of cubic yards occur very infrequently. 2.2 Gravel Supply Results Table 2 presents the gravel sediment budget for the Cedar River above Landsburg. The estimates ranged from a low of 1300 to a high of 9900 cy/yr with the medium estimate being 5300 cy/yr. The low estimate of 1300 cy/yr, based on suspended sediment for the 44 square mile basin between Landsburg and Cedar Falls, may be somewhat low. Although the river only receives gravel from the middle section of its watershed below Chester Morse reservoir, a portion of the suspended load from the upper watershed continues downstream. The total amount of water flow available to carry bedload sediment is also somewhat greater due to the larger watershed area, so the river could erode sediment from its bed and banks. Because flood peaks are moderated by the dam, the actual effective watershed area probably lies between these extremes (King County, 1993). If the entire 122-square mile watershed is used, the low estimate goes up to of 3,700 cy/yr, closer to the medium estimate based on the landslide inventories. Using the highest Snoqualmie suspended sediment load of 1000 tons/sq mi/yr gives a bedload yield of 2700 to7400 cy/yr, depending on which watershed area is chosen. The 1000 tons/sq mi/yr sediment yield is extremely unlikely on the Cedar River due to the low intensity of timber harvest in recent decades. The 9900 cy/yr high estimate, based on generous assumptions about landslide depths, appears to be unreasonably high compared to these regional suspended sediment yields. The medium estimate of 5,300 cy/yr, based on shallower landslide depths, falls within the range suggested by the regional suspended sediment yield data. Some of the 5,300 cy/yr of gravel would not reach Landsburg due to the storage in floodplains and breakdown during transport. The average annual gravel supply from the basin upstream of Landsburg is therefore estimated to be about 4000 to 5000 cy/yr. The 5000 cy/yr figure is supported by anecdotal evidence at the Landsburg Diversion. Upstream of the dam there is a submerged gravel bar in the backwater pool. The volume Draft Phase 2 Report —Cedar River Gravel Study 611712002 El of the bar is about 5000 cy/yr. Before 1975, the bar was commonly bulldozed into the flowing water during the annual forebay cleaning. It reportedly reformed within a year following each removal (Interfluve, 2000). The bar was removed once again in 1989 and reformed within a single flood season during which the peak flow was 3520 cfs, slightly less than a 5-year event (Miller, 2000). Table 3 shows the estimated gravel supply from tributary creeks below Landsburg. The seven creeks that supply gravel to the Cedar River each contribute from 2 to 280 cy/yr, with a total of about 1700 cy/yr. The largest contribution comes from Walsh Lake Diversion Ditch, a large ravine with severe bank erosion near the upper part of the study area. Peterson Creek and Rock Creek are also important contributors of gravel to the river. Table 4 shows gravel supply from cliff retreat and landslides below Landsburg. The total estimated gravel supply is about 6500 cy/yr. Most of the gravel comes from cliff erosion from Segments 5 and 6, in the first six miles below Landsburg. The relatively low gravel supply from further downstream results from two causes. First, cliffs become fewer in number downstream and most are armored at the toe to prevent river erosion. Second, the eroding cliffs downstream from Segment 6 have a much smaller fraction of gravel. In contrast, actively eroding sections of tall cliffs in the upper part of the study area are nearly all. Landslides in the vicinity of RM 14 and RM 4 to 5 are a significant gravel source at the time they occur, but each area produces less than 200 cy/yr when averaged over many decades. These landslides provide significantly larger volumes of sand, which deposits in Segment 1 in Renton. The measurements of cliff retreat are inaccurate due to the scale and quality of the aerial photographs. In many cases the computed potential measurement error was almost as large as the estimated cliff retreat rate. If all the measurements consistently erred in the same direction, the gravel erosion rate from cliffs and landslides could be as small as 2,000 cy/yr or as large as 11,000 cy/yr. HDWever, we believe the 6500 cy/yr figure to be the most likely. If this figure is correct, slightly more gravel is supplied to the river downstream from Landsburg than from the watershed upstream (Figure 2). The total annual bedload yield for the Cedar River is about 12,000 to 13,000 cy/yr. This falls within the 11000 to 15000 cy/yr previous estimate based upon sediment deposition and dredging at the river mouth in Renton (King County, 1993). The King County estimate was based upon 52 years of data and the assumption that about one third of the deposited sediment was of a size likely transported as bedload upstream from Renton. Figure 3 shows gravel supply to each of the Cedar River study segments. An average of 4000 to 5000 cy/yr enters the river above Landsburg. A larger amount enters Segments 5 and 6 primarily from eroding bluffs, but also from Rock Creek and Walsh Lake Diversion Ditch. Downstream from Segment 6, the average annual contribution of gravel from tributary creeks and eroding bluffs is quite minimal. Draft Phase 2 Report — Cedar River Gravel Study 611712002 2.3 Historical Context of Sediment Supply Sediment load both upstream and downstream of Landsburg was considerably greater in the early part of the twentieth century. Timber harvest started during the late 1800s and most of the logging occurred in the 1920s and the 1930s. The 1936 aerial photographs extend upstream only to Landsburg but it is likely that the rate of landsliding increased upstream from there. The 1936 photographs show active landslides in gravel -bearing cliffs between River Miles 3.9 and 17.5. The cliffs, formed of unstable glacial sediments that were oversteepened by river erosion at their base, may in some cases have been affected by timber harvest. Three of those landslide areas have since been protected from riverbank erosion by bank armoring at the toe of the slope, three have revegetated, and four are still active. In addition, erosion of the Walsh Lake diversion ditch delivered a large amount of gravel and sand to the river at RM 20.4. Up to 50,000 cubic yards were eroded from the ditch, forming a deep canyon (King County, 1993). Most of the sediment probably reached the river prior to 1936. The 1936 photograph shows several large bars in the river downstream of the canyon. The sediment deposit was so large that it filled the channel, causing the river to abandon a bend and flow across a previously forested floodplain. The gravel from this source would travel about one-third of a mile per year down the mainstem Cedar River, based on an empirical relationship between bedload transport distance and bankfull width (Beechie, 2001), theoretically reaching RM 5 in the 1970s and the mouth of the river in the 1980s. A later episode of logging occurred in the 1960s and 1970s upstream from Landsburg in the headwaters of Taylor Creek. Aerial photographs show considerable landsliding, with sediment deposition, braiding and channel widening in the lower reaches of Taylor Creek (Foster -Wheeler, 1995a). The rate of gravel movement from Taylor Creek would be on the order of one -tenth mile per year down Taylor Creek. Based on bedload velocities and travel distances, it is likely that much of the sediment from the 1960s landslides has already reached Landsburg and the remainder will move through the Landsburg reach (Segments 1 and 2) over the next 10 to 15 years. In summary, the gravel supply to the Cedar River above Landsburg was probably higher in the early part of the twentieth century than indicated by the sediment budget. Gravel supply is likely to drop slightly in the future due to decreased logging in the protected Cedar River watershed. Draft Phase 2 Report — Cedar River Gravel Study 611712002 0 Figure 1. Cedar River Basin Location Map Watt Study Area MILES �=INK�x Draft Phase 2 Report — Cedar River Gravel Study 611312002 Table 1. Soil Creep Calculation. SOIL CREEP RATE FOR WATE Parameter Value Creep Rate C 0.002 Stream Length L 96.1 Soil Depth D 1.0 Bedload Proportion 65% Conversion factor 1.308 Conversion factor 1609.3 Watershed area 43.4 Soil Creep Erosion Rate (cy/yr) = USE 500 cy ED BETWEEN CEDAR FALLS AND LANDSBURG: Units Remarks m/yr avg slope > 30% miles Type 1 through 5 streams; from 1995 HCP m shallow bedrock soils and deep glacial soils cubic meters to cubic yards miles to meters sq miles below dam (L "1609.3)`2" D*C*1.308 809 cy/yr X 0.65 bedload proportion 526 cy/yr Table 2. Sediment Budget for Cedar River above Landsburg Gravel Supply (cV/Vr) Source Low Medium High Landslides 4800 9200 Soil Creep 500 700 Total 1300 to 3700 5300 9900 Notes: Low estimate is Nelson's (1971) 500 Tons/sq mi/yr suspended sediment load for Snoqualmie River basins, using 44 square mile watershed between Landsburg and Cedar Falls or 122 square mile entire watershed above Landsburg and assuming bedload is 10% of suspended load. (1.65 t/cy conversion factor) Medium and high landslide estimates are based upon Foster Wheeler (1995b) landslide inventory and Dave Beedle (SPU 2002) for post-1990 landslides. Depths and percent bedload size material were assumed. Due to incomplete coverage of 1991 air photos, Foster Wheeler inventory used 1989 photos for much of the watershed. Consequently, some 1990 landslides were probably not counted. Draft Phase 2 Report — Cedar River Gravel Study 6/1712002 Table 3. Gravel Supply from Tributary Creeks Below Landsburg. Gravel Flood Unit Selected Selected RM Major Tributaries Delivery Stability Intensity mi Area 2 ( ) Bedload Bedload Bedload to River Class (Q25/Area ) Yield Yield Yield 2 (T/mi / r) (Tons/yr) (cy/yr) 20.4 Walsh Lake Div. Y 3 Low OW 7 70 461 280 18.5 Rock Cr. Y 1 Low (OW) 11 30 334 202 16.4 Dorre Don some 2 Med 1 30 40 24 14.4 Peterson Y 2.5 Med (lakes) 6 50 316 191 8.8 sewer line Y 3 0 70 3 2 4.1 Molasses I some 1 2 1 High 2 40 73 44 2.4 300 B (BR) Y 3 1 70 69 42 TOTAL 1 281 360 1 1297 1 786 Notes: Gravel delivery, stability class, and flood intensity index were obtained from King County (1993). Stability class 1 = Stable; Stability class 2 = Enlarging; Stability class 3 = Unstable Tributary creeks that do not deliver gravel to the Cedar River were omitted from this table. Bedload yield estimated as 10% of suspended sediment yields from Nelson (1971) for Snoqualmie River watersheds. Areas are rounded so totals may not add up exactly. Draft Phase 2 Report — Cedar River Gravel Study 611712002 9 Table 4. Gravel Supply from Cliff Retreat and Landslides along the Cedar River below Landsburg. Bank a rea rave River Bank Height Rate Erosion Basis for Mile Bank GeologyZ Length (ft) (ft) (ft/yr) % Gravel Rate (cy/yr) Rate Outwash site #3. 21.00 LB Qvr 1,100 17.5 0.06 100 43 RM 18.7 Outwash 1936-1999 20.75 LB Qpf 1,000 110.0 0.63 95 2,438 site #1 Outwash 1936-2000 19.30 RB Qpf 550 175.0 0.47 100 1,675 site #2 Outwash 1936-2000 18.70 RB Qpf 200 150.0 0.06 40 27 site #3 Outwash 18.45 LB Qpf 0 0 Outwash 1936-2000 18.40 RB Qpf 800 140.0 0.42 100 1,742 site #4 GL silt 18.00 RB Qpf big slump 0 0 Till 17.30 LB Qpf very low very low 2 landslides volumes Outwash since from air 14.2-14.6 LB Qpf -1920s 20 100 photos' 1960-1980 2000 Alluvium recession 12.60 RB Qoal 200 34.0 2.40 30 181 site #7 sites 2 + 4 12.00 RB Outwash 300 30.0 0.45 80 120 average GL 10.60 RB silt 0 0 10.20 RB Bedrock 0 0 9.70 RB Bedrock 0 0 volumes Mixed 3 landslides low from air 4.0-5.10 RB Qpf sill ice 1920s (10%?) 1 160 1 photos' 3.70 LB Bedrock 0 2.5,3.0 LB Bedrock 1 0 TOTAL 1 6,487 - Erosion of thousands of cubic yards occurs during infrequent landslides. Little or no gravel reaches the river during decades -long periods between landslides. 2 - Outwash (map unit Qvr): well -sorted clean gravel or sand deposited by rivers emanating from glaciers; GL silt: glaciolacuistrine silt, deposited in pro -glacial lakes; Till: dense, poorly sorted mixture of sand, silt, clay, gravel and boulders, deposited directly from the glacial ice; Qpf: pre -Fraser glacial sediments; Alluvium: Sediments deposited by the Cedar River, sandy gravel in channel, fine sand and silt on flood plain; Qoal: older alluvium, in terraces no longer flooded by the river. Draft Phase 2 Report - Cedar River Gravel Study 611712002 10 Figure 2. Sources of Gravel to the Cedar River Downstream of Landsburg Dam. Draft Phase 2 Report — Cedar River Gravel Study 611712002 11 Figure 3. Estimated Gravel Supply to the Cedar River Study Segments. Landsburg Dam is located between Segments 2 and 3. See Table 5 for locations of segments by river mile. Segment 1 includes the entire supply downstream of Chester Morse Reservoir. Gravel Supply 5000 . ..................... ....................................... ............................. ........................ .................... ........... -........................ 4500 v 4000 Q 3500 3000 a. 2500 >>a 2000 L 1500 m 1000 a 500 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Segment Number Draft Phase 2 Report — Cedar River Gravel Study 611712002 12 3. EFFECTS OF MORPHOLOGY AND HYDRAULICS ON GRAVEL DISTRIBUTION 3.1 Methods Hydraulic Analysis Methodology The Cedar River hydraulic analysis is comprised of three HEC-RAS 2.2 (Hydrologic Engineering Center River Analysis System) computer models that encompass the river from the mouth to about one mile upstream of the Landsburg Dam. HEC-RAS is a cross- section based hydraulic analysis model. HEC-RAS Cedar River Reach Model Origin and Purpose Model Reach Lower From mouth to river Modeled for City of Renton, Washington by mile 5.3 Northwest Hydraulic Consultants, Inc. to update National Flood Insurance Program maps Middle From river mile 4.8 Modeled for King County, Washington by Harper to 22.1 Houf Righellis, Inc. to update National Flood Insurance Program maps Upper From Landsburg Created for this gravel study Dam to about one mile upstream The lower and middle reaches cross -sections were developed from a combination of aerial photogrammetric mapped topographc contours and field surveyed channel area cross -sections at a spacing of about 10 to 12 per river mile. From the mouth of the river to about river mile 11 the aerial photographs were taken in March 2000 and the field surveying for the cross -sections were obtained in the summer of 2000. From about river mile 11 to river mile 22 the aerial photographs were taken in March 1999 and the field surveying for the cross -sections were obtained in the summer of 1999. The upper model was surveyed using only field -surveyed cross -sections that were obtained in the summer of 2001. River miles (RM) for the upper model were determined using the end point of the middle model as a starting point. This results in Landsburg Diversion being located at RM 22.61 instead of RM 21.8 as previously described by USGS and other agencies. The February 2001 earthquake caused a landslide at about river mile 5 that significantly altered that portion of the Cedar River. That area was re -photographed on March 2001 and a topographic and cross-section resurvey was completed soon after. Coincidently, both the lower and middle reach models model the landslide -impacted area as they overlap in this precise area. The updated information was used to modify the middle reach model, but was not included in the lower reach model provided for this study. Draft Phase 2 Report —Cedar River Gravel Study 611712002 13 A total of six cross -sections were either modified or added to the middle reach model at approximate river miles 5.6, 10.0, 11.4, 12.1, 13.2, and 18.1 based on data collected for this study. All three models were kept separate as merging them provided little value to this study. The lower and middle reach models differed as mentioned above. The Landsburg Dam separates the middle and upper reach models without overlap. The Landsburg Dam is operated to maintain the water level range at the dam to two -foot. That elevation range was used for the entire range of model flows Five flow levels were modeled for this study: the discharges for floods with recurrence intervals of 1.2, 1.5, 5, 10 and 100 years (Appendix B). A previous study (CES, 1991) showed the 1.2 year event is the lowest flow that caused scour of spawning grounds. The 1.5 year event is the discharge at which a river typically reaches the top of its banks, the "bankfull flood". The 5 year and larger events were used to evaluate the extent of channel confinement, which affects channel morphology and bed scour. Segment -Level Analysis Approach The study area was divided into 22 segments based upon gradient and confinement during Phase I of the project. Segment locations and sampled cross -sections are shown on the maps appended to the Phase I report (Jones and Stokes, 2002). The segments were numbered consecutively from upstream to downstream, with Segment 1 starting approximately one mile upstream from the Landsburg diversion and Segment 22 ending at the river mouth at Renton. Segment length varied from 0.3 to 2.9 miles, with between 2 and 29 flood study cross -sections per river segment. Segment 3, the short reach between Landsburg and the pipeline crossing, was not included in the available hydraulic models. Information for the 100-year flood in Segment 3 was obtained from a floodplain study for the Landsburg Fish Passage Project (MWH, 2001). Average values of hydraulic variables for each river segment were computed by summing the values and then dividing by the number of cross -sections. The hydraulic variables included energy gradient, shear stress in the main channel bed, flooded width, and confinement ratio (flooded width divided by typical bankfull width). Data on available spawning area were obtained from a 2000 habitat survey for the entire river from Renton to the Landsburg pipeline (R2, 2001). The R2 available spawning area data were apportioned into each segment of the river in Phase I of this study (Jones and Stokes, 2002). The length of armored banks and cliffs in each study segment was measured from topographic maps, King County facilities maps, and field observations. Scatter plots were used to identify relationships among the hydraulic variables, morphologic variables and available spawning area on a segment basis. Data used for the segment -level analysis were collected prior to the February 2001 earthquake in which the Segments 17 and 18 were affected by a large landslide. Draft Phase 2 Report — Cedar River Grm,el Study 611712002 14 Cross-section analysis approach The HEC-RAS program computes energy gradient and bed shear stress at each cross section. The shear stress computation is based on the energy gradient. The energy gradient output by the model was found to have some strange anomalies at particular cross -sections. For example, the output shows extremely high local energy gradients at some individual cross -sections even though the profiles of water surface and energy gradient were much flatter and parallel. Therefore, this portion of the analysis was performed using the water surface gradient. Average water surface gradient at each cross-section was computed using the water surface elevation change between the cross-section above and the cross-section below the studied cross-section, divided by distance. Since the cross -sections were placed an average of 400-500 feet apart, the computed water surface slope covered a distance of 800-1000 feet. In some cases, this average water surface slope differed significantly from the local bed slope and the low flow water surface slope, both of which were measured in the field. The field measurements of slope were made for a channel length of two channel widths or typically about 200 feet. Additional parameters were computed from the HEC- RAS output, using water surface gradient where appropriate: • Shear stress - slope times the weight of water overlying the bed. • Gradient -confinement index - the gradient divided by confinement and multiplied by 1000 feet. • Confinement ratio - the width of flooded area for a given flood discharge divided by bankfull width. • Critical shear stress - the shear stress that would mobilize the median diameter (D50) of subsurface sediment in the gravel bed, computed using Andrews' (1983, 1984) relation for gravel beds with mixed grain sizes. • Excess shear stress ratio - the shear stress for a given flood divided by the critical shear stress. At an excess shear stress ratio of 1.0 (bed shear stress = critical shear stress) the armored gravel bed starts to move and bedload transport begins. • Predicted mobile size - The Andrews equation was rearranged to predict the median diameter of sediment that would be mobilized at excess shear stress ratio = 1. The calculations of critical shear stress and predicted mobile size both require the median diameter of subsurface gravel. The surface gravel median diameter for the pebble counts was divided by 1.7, which was average surface -to -subsurface D50 ratio at 18 gravel bars for which both surface and subsurface gravel were measured (Jones and Stokes, 2002; King County, 1993). Most sites had ratios between 1.5 and 2.0. Use of the average ratio of 1.7 would yield less than a 15% difference in results of the two calculated parameters. Field data used for the cross-section analysis include pebble counts of sediment size, bankfull width, bankfull depth, local gradient of the water surface, local bed gradient, and available spawning area. The last three parameters were measured for a length of channel two bankfull widths in length, centered on the cross-section. Based on the pebble counts, the following parameters were computed for this analysis: Draft Phase 2 Report — Cedar River Gravel Study 611712002 15 • D50 (median diameter) — the gravel size for which 50% of the sampled particles were finer. • D84, D 16 — the gravel size for which 84 or 16%, respectively, of the particles were finer. • Percentage of the pebble count material in spawnable size range 38 —152 min (chinook spawning preferences; Burton et al., 2000). • Percentage of the pebble count material in spawnable size range 13-152 min (steelhead, sockeye, chinook and coho; CES, 1991). • Sorting index (D84 — D16) 112 (Kondolf and Wolman, 1993). Two primary bed material data sets were used for analysis. The first was a set of 32 sites with pebble count data collected at or near the location of the flood -study HEC-RAS cross -sections. The three cross -sections in the Landsburg pool (Segment 2) were omitted from this data set but were used for hydraulic modeling. Two had no pebble count data due to the water depth and the third was primarily sand deposited when the dam gates were closed. The fine sediment in these pool sections does not represent transport conditions when the gates were open. At several cross -sections, more than one pebble count was made to characterize different areas of the channel such as low submerged bars. At each cross-section, the pebble count covering the largest, most representative portion of the riverbed was selected for analysis. In one case, two adjacent pebble counts were combined to make a single pebble count for the analysis. The second data set was a subset of the 32 cross -sections. Uniform flow is an essential condition for the applicability of sediment transport or initial motion formulas. The fourteen cross -sections that were chosen for analysis met the following uniform flow criteria: • Cross-section was located within a single habitat unit, such as a glide or a riffle and not at a transition between two units; • Cross-section was relatively flat in the cross -stream direction; • Gradient did not change abruptly at the cross-section; • The pebble count covered most of the bed; and • The pebble count was located at the HEC-RAS cross-section as opposed to some distance away. Slightly less than half the data set met the uniform flow criteria. At these 14 cross - sections, sediment size on the bed is most likely to reflect the hydraulic conditions in the flood model and therefore produce reasonable relationships with the least amount of scatter. Many of the HEC-RAS cross -sections were located at the top of a steep riffle at a transition in gradient and habitat unit. These conditions in many cases resulted in spawning gravel distributions that were typical of the segment and were therefore sampled. However, the conditions at these transitions did not meet uniform flow criteria due to local hydraulic influences on bed material distributions. Draft Phase 2 Report — Cedar River Gravel Study 611712002 0 For both the large and small data sets, scatter plots were prepared to identify relationships among variables. Histograms were made portraying a single variable as it changed along the river to identify trends in the downstream direction. Initiation of motion and bedload transport calculations were made for the uniform cross-section data set for a selected range of floods. These two data sets described above only included sediment data from this study (Jones and Stokes, 2001) due to consistent methods of data collection at the flood -study cross - sections. However, sediment data from previous studies on the Cedar were included in graphs portraying the range of sediment sizes along the length of the river. This greater data set of sediment sizes was used to identify along -river trends and examine the full range of variability of sediment size. Surface and subsurface data from both bars and riverbed samples were considered. 3.2 Results Segment -Level Findings Figure 4 is a profile showing the gradient of the Cedar River study segments. The channel generally becomes steeper upstream, from 0.2% at the river mouth to between 0.5% and 0.7% between River Mile 15 (Segment 8) and Landsburg. The pool above the Landsburg diversion dam, Segment 2, has an average gradient of 0.1%. The channel steepens somewhat to 0.3% in Segment 1 above the pool. This relatively low gradient continues for approximately two miles upstream of Landsburg dam and the river steepens again with gradients between 0.5% and 2.1% (Figure 5). The Cedar River valley floor is composed of sand and gravel alluvium, sediments laid down by the river over thousands of years. The alluvium is generally 1,500 to 2,000 feet wide below River Mile 18 (Booth, 1995). Above River Mile 18 (Segment 6), the valley narrows to a 500 to 1,000 foot wide strip of alluvium. The valley is extremely constricted for about one mile below the Landsburg diversion. The strip of alluvium is only 100 to 300 feet wide (Segments 3 and 4) and bedrock is exposed in the riverbed at RM 20.25. Above Landsburg Dam, the valley widens slightly and the alluvium is typically a few hundred feet wide (Philips, 1984). The Cedar River no longer floods the full width of its valley bottom as a result of flow regulation by Chester Morse reservoir, le• �ees, and channel incision. The average flooded width predicted by the HEC-RAS model was divided by typical bankfull width to obtain a confinement ratio for each river segment. A value of 1.0 indicates that flow is contained entirely within the channel. For the 100-year flood, ratios of 1 to 2 are normally considered confined, larger than 4 is considered unconfined and intermediate values of 2 to 4, moderately confined. A river in equilibrium normally spills onto the floodplain at flows exceeding a 1.5-year recurrence interval. Draft Phase 2 Report - Cedar River Gravel Study 611712002 17 On the Cedar River many segments remain tightly confined even in the 5 or 10-year flood, and some are tightly confined even in a 100-year flood (Table 5). Because confinement affects flood depth, the deepest, fastest flows occur in segments that are both steep and tightly confined. These conditions typically occur from Maple Valley and further upstream. Figure 6 is a plot of the gradient -confinement index, which is gradient divided by confinement and multiplied by 1,000. A low value of the gradient - confinement index indicates low gradient and unconfined conditions, whereas a high value indicates either a steep gradient, tight confinement, or both. Segments 4, 5, 6, and 9 have high gradient -confinement indices, whereas 14 and 19 have very low values. In general the lower values of this index occur downstream from Segment 9, as well as upstream from Landsburg in Segment 1 and 2. The river's ability to migrate laterally across its floodplain is constrained by cliffs and armored banks. Most segments of the Cedar River are quite constrained (Figures 7 and 8). Cliffs and armored banks tend to be located at the outsides of river bends, where they effectively prevent channel migration even if substantially less than 50% of one bank is armored. Channel migration is also reduced by flood control by Chester Morse Reservoir, which reduces the energy available for bank erosion. Active channel migration presently occurs only in Segment 14, however there is potential for channel migration to occur in 15, 19, 16, 12 and 8 (King County, 1993). Perennial side channels were formerly common but now occur in only three river Segments: 19, 15 and 8. Available spawning area was characterized in a habitat survey in 2000 (R2, 2001). The percent of bed area that contains gravel suitable for spawning was quite low in Reaches 4-10, 12, 17 and 22 (Figure 9). The segments with the highest available spawning area were 19, 14, and 15, which had 55%, 45% and 32% of bed area in potential spawning gravels, respectively. No data were collected in Segments 1-3. Based on visual observations, available spawning area is probably quite high in Segment 1, non-existent in Segment 2 (the Landsburg Pool), and quite low (below 10%) in Segment 3. The three segments with greater than 30% available spawning area occurred within a fairly narrow range of gradients, between 0.3 and 0.4% (Figure 10). Moderate amounts of spawning gravel (20-30% of segment) occurred in a somewhat wider band of gradients, from 0.3-0.5%. Segments with less than 10% available spawning area occurred over a very wide range of gradients, from 0.2 to 0.8%. These results suggest that gradient alone does not control the amount of available spawning area but sets an upper limit on the potential spawning area as indicated by the sloping line on the graph. Low available spawning area in segments with gradients below 0.3% is likely due to sand that deposits near the downstream end of the river. Note that these results are for energy gradient, which is output directly from the HEC-RAS model. Similar results were obtained with the 1.5-year floodwater surface gradient, the only difference being that gradients were slightly smaller in some cases. Figure 11 shows available spawning area in relation to the gradient -confinement index. Low values of this index indicate that the river segment was flatter and generally less confined, while high values of this index indicate a steeper, more confined condition. Draft Phase 2 Report — Cedar River Grm,el Study 611712002 It] Confinement would be expected to result in deeper flows, higher sediment transport rates, and coarser sediment. As with gradient alone, the gradient -confinement index appears to set an upper limit for the amount of spawning area. Above a value of about 3 or 4, only segments with less than 11% spawning area occurred. The two segments with highest spawning area had gradient -confinement indices below 1. In the middle range of about 12% to 35% available spawning area, there was no clear relationship. Shear stress on the riverbed is the driving force that causes gravel to be transported. Shear stress is the product of water depth, slope, and the unit weight of water. Shear stress is determined largely by gradient and discharge, with a smaller influence by confinement. During floods, flow depth and shear stress are larger where the channel is confined, and lower in unconfined reaches where water spills out onto the floodplain. There is a weak inverse correlation between shear stress and available spawning area (Figure 12). At high shear stress, sediment tends to be too coarse for spawning. At the very low end of the spectrum is Segment 22, where the limiting factor is too much sand deposition due to low velocity near Lake Washington. Thus this data point was excluded from the correlation. The solid regression line is drawn through the middle of the data. It may be more useful to think of shear stress as a limiting factor delineating an envelope of potential spawning area, as shown with the dashed line. This line shows the maximum spawning area that could be expected to occur at a given shear stress with other factors also controlling the amount of spawning area within these bounds. There is a strong correlation between shear stress and energy gradient of the river segments showing that on the Cedar River, gradient is the primary control on shear stress (Figure 13). A similar regression of shear stress to gradient -confinement index showed a weaker relationship, with a strong positive slope but an R2 of only 0.65. The three segments with over than 30% available spawning area had less than 50% armored banks (Figure 14), and the two highest values occurred in segments with perennial side channels, active gravel deposition, low confinement. These features are indicative of active channel formation processes such as channel migration. These processes are largely or completely absent in other segments of the river (King County, 1993). In summary, segments with high gradients, high shear stresses, and high gradient - confinement indices had low available spawning area (less than 11%) indicating that high values of these parameters are limiting. Segments with over 30% available spawning area had low values of these parameters. In between these extremes, segments showed a wide range of available spawning area that was not explained by any of the morphologic or hydrologic variables. To some extent, averaging the individual cross -sections in a stream segment masks local variations in gradient and confinement that result in local pockets of good spawning areas. For instance, there is an extremely wide area in the upstream end of Segment 20. Segment 8 has variable confinement and gradient within its length and contains a perennial side channel with spawning gravel. Draft Phase 2 Report — Cedar River Gravel Study 611712002 19 Table 5. Location, Flood Confinement and Average Gradient of Cedar River Studv Seements Segment Number From RM: To RM: Segment Length (miles) Description Average Confinement Ratio' (ft/ft) Average Gradientb (%) Gradient - Confinement Classd 5-year flood 10-year flood 100-year flood 1 23.64 23.11 0.53 Upstream of Landsburg pool 2.59 2.82 4.46 0.30% gc 2 23.11 22.61 0.50 Landsburg pool 3.34 3.75 3.92 0.08% gc 3 22.61 22.15 0.46 Diversion dam to pipeline 1.58 0.6% GC 4 22.15 21.00 1.15 Steep, tightly confined 0.99 1.03 1.25 0.64% GC 5 21.00 19.098 1.902 Confined w/ sed sources 1.25 1.54 2.93 0.58% GC 6 19.098 18.00 1.098 Tight bends w/ sed sources 1.36 1.75 3.61 0.67% GC 7 18.00 16.573 1.427 Upper Dorre Don, variable confinement 1.79 2.66 5.01 0.48% GC 8 16.573 15.598 0.975 Lower Dorre Don, unconfined, side channels 4.42 4.84 9.32 0.55% Gc 9 15.598 14.75 0.848 Maple Valley confined, steeper 1.20 1.99 4.96 0.57% GC 10 14.75 14.064 0.686 Flatter, variable confinement; Peterson Cr. 1.66 4.78 8.08 0.45% GC 11 11.064 ' 12.138 1.926 Bends, levees, variable confinement 1.64 2.96 8.43 0.42% GC 12 12.138 11.689 0.449 Lion's Club unconfined, flat 2.22 8.07 13.84 0.38% gc 13 11.689 11.012 0.677 Cedar Grove, floods despite levees 2.24 2.98 8.55 0.36% gc 14 11.012 10.226 0.786 Unconfined bends, side channels, LWD jams 5.15 5.51 8.42 0.36% gc 15 10.226 9.625 0.601 Moderately confined, bedrock bends, flatter 1.69 2.44 3.82 0.36% gC 16 9.625 6.694 2.931 Jones Road, mostly confined 1.59 1.88 5.10 0.43% gC 17 6.694 5.21 1.484 Elliott Br, flatter, confined 1.89° 3.00° 5.980 0.33OW gC 18 5.21 4.841 0.369 2001 Landslide 2.640 4.16° 10.05° 0.570/,° Gc 19 4.841 4.576 0.265 Unconfined, side channels, Renton golf course 4.12° 5.21 ° 10.13 ° 0.41%0 gc 20 4.576 3.25 1.326 Maplewood, mostly confined 1.22 1.33 3.04 0.34% gC 21 3.25 1.633 1.617 Confined, even flatter 1.05 1.12 1.82 0.27% gC 22 1.633 0 1.633 Renton channel 1.90 1.94 2.11 0.18% gC Notes a Calculated as the ratio of the flooded width to the wetted width of the bankfull channel, average value for each HEC-RAS cross-section in segment b Water -surface gradient of 1.5 year flood, except segment 3 which is 100-year flood. Values represent conditions prior to February 2001 landslide d A four category classification based on gradient and confinement values. Gradient: steeper "G" values are >0.4%, and flatter "g' values are <= 0.4%. Confinement: more constrained "C" values are <2.0, flood prone "c" values are >=2.0 Draft Phase 2 Report - Cedar River Grave! Study 611712002 20 Figure 4. Lower Cedar River Profile Showing Study Segments. Lower Cedar River Stream Profile Lake Washington to Landburg 600 . .......................................................................................................................................................................................................................................... Segment numbers are shown below the line. 03% 1 0 1 O/C 1— 0 50�1i L6 500 - 0.7 3 0 060 0 5 400 0. 7 O1Xq .2 0.50% /o 0.6 > 4) LL 0.60 "W 8 300 0 0.40/( 10 U 4 �/ 0 M U- 200 14 0 ,q/ 16 3 cc 100 0. 3 % 4n 0.2% 20 0 . 2 I --F- 0 5 10 15 20 25 Distance in Miles Above Mouth 21 Drqfl !'base 2 Report - Cedar River Gravel Study 611712002 Drqfl !'base 2 Report - Cedar River Gravel Study 611712002 a to m D 0 .a -14 Q r4 q 0 Cd m W Figure 5 900 850 750 700 550 500 UPPER CEDAR RIVER STREAM PROFILE Landsburg to Taylor Creek 0.6% 0.7% 1.2 0.5% 0.8% 0.6% 1.0 O.B 0.6% 0.4% 0.4% 0.3% 21 23 25 27 29 Distance in Miles Above Mouth Source: Final Report, Cedar River Instream Flow and Salmonid Habitat Utilization Study, Seattle Water Department, Cascade Environmental Services, Inc., October 1991. Gradient/Confinement Index 5-year flood g........................................................................................................................._..__...... 7 c 6 E c 5 00 4 U 3 CD 2 ' ,� >>4 L 0 � 1 2 3 ' 4 5 6 7 8 9 10 11 12 13 14 T 16 17c 18c 13c 20 21 22 Segment Number Figure 6. Gradient -Confinement Index by River Segment. High values indicate steep and/or confined. Low values indicate flat and/or unconfined. 120 100 80 d 60 L 0 E 40 L 20 0 Unarmored Cliff i r ® i 1 2 3 4 5 6 7 8 9 13 11 12 13 14 15 15 17c 1gc 19c 20 21 22 Segment Number Figure 7. Extent of Unarmored Cliffs by River Segment. An armored cliff ratio of 100% indicates that the entire channel length has cliffs on either bank where the toe of the cliff is unprotected and eroding particles are delivered directly to the channel. Draft Phase 2 Report — Cedar River Gravel Study 611712002 23 Armored Bank 250 200 cc 150 � 3 100 0 50 Q 0 1 2 3 4 5 6 7 8 9 13 11 12 13 14 15 15 17c Sc Sc 20 21 22 Segment Number Figure 8. Extent of Armored Banks by River Segment. Armored bank ratio of 100% indicates that bank length equivalent to one side of the segment was armored; 200% indicates that both banks are armored. Spawning Area by Segment from R2 habitats u rvey, 2000 c� 60......................................................................................................................................................................................... 50 cua)40 N 30 (, o 0 20 •; `6 10 QQ <_ no data -> 0I M 1 2 3 4 5 6 7 8 9 11) 11 12 13 14 15 15 17c Sc 19c 20 21 22 Segment Number Figure 9. Available Spawning Area by River Segment. From Year 2000 habitat survey by R2 Resources. Draft Phase 2 Report — Cedar River Gravel Stud; • 611712002 M11 5-year flood d60 . ................................................... L a 50 c c 40 3' fl, N 30 N o 20 d 0 10 > 0 : Figure 10. Gradient and Available Spawning Area. Outliers are labeled by segment number. 5-year flood 60 L Q 50 tF� 40 3 a H 30 co a2 0 20 .n o 10 Q 0 0 1 2 3 4 5 6 7 8 (Gradient / Confinement) * 1000 19 19 ♦14 15 6 • ♦ • 5, 9 4 Figure 11. Gradient -Confinement Index and Available Spawning Area. Outliers are labeled by segment number. Draft Phase 2 Report - Cedar River Grave! Study 611712002 25 5-year flood 60............................................................................................................................................................................... ♦ 19 < = 50 r R40 R=0.376 �......... a w 30 mo20lu ♦ ♦♦ � o • > p O 22 Q 0.0 0.5 1.0 1.5 2.0 2.5 Bed Shear Stress (Ib/ft) Figure 12. Shear Stress and Available Spawning Area. Shear stress was computed for this figure with the energy gradient. Using water surface gradient results in a similar relationship but no shear stress exceeded 2.0. 5-year flood 0.90%.................................................................................................................................................................v ♦ R2 = 0.9507 I 0.80% IF 0.70% • 0.60% d > V 0.50% •• 0 0.40% s 0.30% W 0.20% 0.10% 0.00% 0.0 1.0 2.0 3.0 Bed Shear Stress (Ib/ft) Figure 13. Shear Stress and Energy Gradient. Draft Phase 2 Report — Cedar, River Gravel Study 611712002 26 Armored Bank 60................................................................................................................................................................................ d ♦ 19 a 50 r ♦ 14 40 3 ♦15 o, y 30 a0 20 �o v 10 Q . ♦ 22 0 0 50 100 150 200 Armored Bank Ratio (%) Figure 14. Armored Banks and Available Spawning Area. Armored bank ratio of 100% indicates that a bank length equivalent to one side of the segment was armored, 200% indicates that both banks were armored. Cross -Section Level Findings Surface sediment size on the Cedar River varies widely over short distances (Figure 15). From River Mile 9 to 19, the median surface sediment on the bed ranges from 30 to 90 mm with no apparent trend as one goes downstream. Samples taken within a few hundred feet of each other can vary as much as 40 mm in median diameter due to local morphology and hydraulics. Sediment sampled in riffles spanned the full range of 30 to 90 mm whereas sediment in glides had a somewhat narrower range of 31 to 55 mm. From River Mile 6 to Lake Washington, there is a gradual downstream decline in gravel size culminating in very fine gravel and sand at the river mouth. Sediment tends to be much coarser between RM 19 and Landsburg Dam at RM 22.61. Median diameters commonly exceed 150 mm, but there are small areas of spawning gravel in the 35 to 60 mm range. Sediment sampled in the first mile above Landsburg is in the 32 to 53 mm range. The bed presumably coarsens upstream from RM 24 due to the steeper gradients. Subsurface samples showed an even larger range of variation with D50s from 12 to 72 mm in the middle section of the study area. Most of the samples with finer sediment were collected underwater in spawnable gravels. Even after compositing 2 to 4 underwater samples the typical sample size was only 1-2 cubic feet. Samples this small typically under -represent coarse sediment, particularly when McNeil samplers are used (Bunte and Abt, 2001). These small samples are judged unrepresentative of bedload moving through Draft Phase 2 Report -Cedar River Gravel Study 611712002 27 the system but are useful for discerning trends in fine sediment (see Jones and Stokes, 2002, for analysis of fine sediment conditions). The subsurface samples from gravel bars had sizes of 3 to 9 cubic feet, with sample size increasing with coarseness. This sample size is generally adequate to define the median diameter (King County, 1993). Subsurface samples collected on bars show a similar decline in sediment size below about RM 6 (Figure 16). Upstream of RM 6 the samples have a very wide range of sizes. Unlike the surface data, there is no sign of coarsening from RM 19 to Landsburg. This is because in the areas of coarse sediment there were no bars to sample. The only bar sampled in that reach occurred in a local area with some finer sediment deposits. Three small samples were collected on the bar in the Landsburg pool. Two of these three samples were finer than is typical of the river while the third was in a range typical of the rest of the bar data. The small sample size makes these results suspect as small samples tend to bias against coarse sediment. The bar data upstream of RM 6 shows median subsurface sizes in the same range as the surface samples from the riverbed, in this case from approximately 45 mm to 75 mm. Pebble counts of the surface armor layer were performed prior to collecting the bulk surface samples directly underneath. The mean and median ratios of surface D50 to subsurface D50 were 1.7 and 1.5 respectively for bars, and 2.3 and 2.0 respectively for underwater in -channel samples The higher ratios for underwater samples are probably due to the small subsurface bulk samples being finer due to the sampling bias against coarse clasts. A ratio of 1.7 was used in the formula for calculating initial motion (see Section 3.1, above). Pebble counts were located at cross sections where gradient, confinement, and bed material were typical of the rest of the segment (Section 2.2 of Phase 1 report in Jones and Stokes, 2002). In most segments these typical conditions included spawnable gravels. Two sample locations (one in each of Segments 4 and 5) were located at cross -sections that had little or no accumulations of spawnable gravel in the vicinity, although some gravels were distributed across a matrix of larger cobbles and small boulders. Two other pebble counts (one each in Segments 7 and 8) were placed in areas that had only small patches of spawning gravels, with less than 5-10% available spawning area. Most of the pebble counts had more than 70% of the grains in the 13-152 mm (medium gravel to small cobble) size range reported for spawning gravels on the Cedar River (CES, 1991; Table D, Appendix). Only the two cross sections with no spawning gravel in the vicinity had fewer than 50% of pebbles counted in that size range. For the narrower 38 - 152 mm (large gravel to small cobble) size range reported for chinook spawning by Burton et al. (2000), half the cross -sections had less than 50% of pebbles in that size range, whereas the other half had more than 50%. Only three cross -sections had 70% of pebbles in that size range. The percentage of gravel in the spawnable size classes did not correlate with any of the other variables analyzed. Sorting index also did not correlate with any of the other variables. Draft Phase 2 Report — Cedar River Gravel Study 611712002 28 The amount of available spawning area (ASA) in the vicinity of the cross -sections was weakly correlated with gravel size. Spawning area decreased as D50 or D84 increased (Figure 17). Some cross -sections were located at riffle crests with a steep riffle downstream in which spawning area was not optimal due to the coarse grain size. Consequently, the spawning area estimates varied quite widely depending on morphology downstream from the pebble count sample area. Neither ASA nor sediment size correlated with shear stress, gradient, nor any of the other hydraulic parameters from the HEC-RAS model output for the 32-cross-section data set. Instead a wide range of sediment size and spawning area occurred for any given value of shear stress or other parameters. The results suggest the size and amount of spawning gravel is controlled by local hydraulics and channel morphology at a habitat -unit scale that is much smaller than the HEC-RAS model can replicate. Median diameter (D50) showed little relationship to HEC-RAS water surface gradient, only a slight improvement with low -flow water surface gradient, and had the best (albeit still weak) correlation with local bed gradient (Figure 18). Spawning area showed a similar improvement using local bed gradient although the correlation was still poor (Figure 19). Spawning areas tended to be more abundant where local bed gradient was less than 0.5 percent and especially where gradient was negative such as at a pool tail -out. The eight cross -sections located at glides had available spawning area in the range of 50-85%, whereas the 24 riffles had a much wider range of ASA and gradients. The glide pebble counts all had median diameters of 55 mm or less, whereas the riffles encompassed a much wider size range including coarser sediments. Confinement ratio appears to exert a limiting condition on the amount of coarse sediment found in the pebble counts, similar to the segment -level findings. The very coarsest sediment occurred in confined cross -sections whereas unconfined channel cross -sections (confinement ratio > 4.0) had virtually no large cobbles (Figure 20). Considering gradient and confinement together, cross -sections without abundant large cobbles occurred only in flatter, less confined conditions (Figure 21). Median grain diameter (D50) was not affected by confinement for the cross -sections in this data set. Data analysis for the 14 cross -sections that met uniform flow criteria showed additional relationships between sediment size and hydraulic variables. Most of the observed median diameters (D50) were close to the predicted mobile D50 for either the 1.2 or 1.5- year flood, indicating that mobility of typical gravels beds starts at about the 1.2-year flood (Figure 22). Finer patches of gravel would begin to move at smaller flows. This is the range normally found for gravel -bedded rivers and indicates the appropriateness of using the Andrews equation for predicting the sediment size that would move at a given discharge. The 1.2-year flood was the lowest flow that caused scour of spawning gravels in a previous study on the Cedar River (CES, 1991). Surface grain size increased with shear stress for most of the uniform cross -sections (Figure 22). Results shown are for the 1.2-year flood. A similar but less -pronounced trend was apparent for the 5-year and larger floods. The pebble count at RM 21.61 may have Draft Phase 2 Report — Cedar River Gravel Studv 611712002 29 included lag boulders that are not transportable in the current flood regime, resulting in the abnormally high D84. Figure 23 (a) shows how the predicted mobile median diameter changes from upstream to downstream for the cross -sections with uniform flow. The mobile median diameter is the size that would be just beginning to move at the 1.2-year flood. Both upstream of Landsburg and downstream from RM 15, gravel beds with a median diameter of about 30 to 50 mm would be starting to mobilize at this discharge. In the first few miles downstream of Landsburg, cobble beds with median diameters of 80 mm would already be mobile at the 1.2-year flood. Figure 23 (b) shows the predicted mobile size for all the cross -sections. The same general trend is apparent, despite considerable fluctuation due to non -uniform bed geometry that rendered many of the cross -sections unsuitable to sediment transport calculations. Another way to view these results is to consider the mobility of a single size of gravel as it moves downstream. Figure 24 shows the excess shear stress ratio for sediment with a median surface diameter of 40 mm (1.6 in). This is the median size of spawning gravel sampled at all the cross -sections and is also typical of sediment sampled upstream of Landsburg Dam. Initial motion would begin at an excess shear stress ratio of 1.0. Full disruption of the bed and transport of the entire range of grain sizes would occur at a ratio above about 1.3 (Petit, 1994). For the 1.5-year flood shown in Figure 24, most of the uniform cross -sections are at about the initial motion threshold, but cross -sections in the six miles downstream of Landsburg have high excess shear stress. In these steeper segments, 40 mm gravel would be transported rapidly and would only be deposited in local areas with sheltered velocities or anomalously low gradients. This is most clear in the uniform cross -sections (Figure 24 (a)), but is also the general trend in all the cross - sections (Figure 24 (b)) despite a some fluctuation. Draft Phase 2 Report —Cedar River Grm,el Study 611712002 30 Landsburg _ Dam o Figure 15. Surface Median Diameter Measured in Pebble Counts on the Riverbed. All data are compiled and referenced in Jones and Stokes (2002). The circled point near River Mile 23 is sandy sediment deposited in the Landsburg pool and is not representative of bed conditions when dam gates are open during floods. Draft Phase 2 Report - Cedar River Gravel Study 611712002 31 Figure 15. Surface Median Diameter Measured in Pebble Counts on the Riverbed. All data are compiled and referenced in Jones and Stokes (2002). The circled point near River Mile 23 is sandy sediment deposited in the Landsburg pool and is not representative of bed conditions when dam gates are open during floods. Draft Phase 2 Report - Cedar River Gravel Study 611712002 31 CD LO 80 70 d N in 60 d 50 � 40 4% E N 30 20 es 10 N 0 25 20 15 10 5 0 River Mile ♦ bars Q ri\er channel o • o ♦ O O ♦ Q O Figure 16. Comparison of Subsurface Samples from Gravel Bars Versus River Channel. Bar samples typically were many times larger than the in -channel samples which were collected below water by McNeil sampler or shovel. Large cobbles were probably systematically under -represented in the river channel samples and three small samples of the bar in Landsburg pool (RM 22.7). CC m 100 _...._ Q ® o 0 a� 80 -In 0 0 3 60 0 0 � o o a� W 40 00 m . o . o 20 Q 0 0 100 200 300 400 Surface grain size (mm) • D60 o D84 Figure 17. Surface Sediment Size and Available Spawning Area. Draft Phase 2 Report —Cedar River Gravel Study 6/17/2002 3 2 a. C. Figure 18. Relationship Between Median Sediment Size and Gradient. a) water surface gradient for 1.5 year flood from HEC-RAS model over average distance of 800 to 1000 ft, b) water surface gradient at low flow over average distance of about 200 ft, c) local bed gradient over average distance of 200 ft. Negative gradient indicates bed was rising in downstream direction at a pool tailout. Draft Phase 2 Report — Cedar River Gravel Study 611712002 33 90 . ........................................................................................................................................................................... 13 80 M 70 60 cv W 50rn 13 40 0 .S 30 CL W 20 10 0 -1.0% 0.0% 1.0% 2.0% Local Bed Slope (0/4 ♦ riffle r3 glide] Figure 19. Spawning Area and Local Bed Slope. 350 . ................................................................................................................................................................. 300 A 21.61 E 19.87 250 co 200 .0 U) 150 AA A, la cobbles cm loo ----------- A -- -------------- .... small cobbles A............ A (D A A A 50 AAAA 0 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 Confinement Ratio (flooded width/bankfull width) Draft Phase 2 Report —Cedar River Gravel Studi- 611712002 34 Figure 20. Effect of 10-year Flood Confinement Ratio on Surface Grain Size. Figure 20. Effect of 10-year Flood Confinement Ratio on Surface Grain Size. 350........................................................................................................................................................ 19.8 • 300 21.6 a c 250 d N C E 200 R E 150 • _____ large cobbles___; ------------ �------- small cobbles 100 4b 50 0 0.00 2.00 4.00 6.00 8.00 Water Surface Gradient divided by Confinement x 1000 Figure 21. Gradient -Confinement Index aad Surface Sediment Size for 10-Year Flood. High gradient -confinement index indicates steep and/or confined condition. 120 .............. ..................... .. 0 100 as 10.02 C 80 �o �^ E m E 60 �o y 40 m H 20 .a O 0 0 20 40 60 80 100 120 Predicted Mobile Size D50 (mm) 01.5 year flood :is 1.2 year flood i 1 IMMOBILE f 21.61 s° o � o j MOBILE 00 o° Figure 22. Predicted Mobile Size Compared to Observed Surface Sediment. The line marks the point where bed shear stress equals critical shear stress, the threshold of initial motion of the gravel bed. Only cross -sections that met uniform flow criteria are shown. Draft Phase 2 Report —Cedar River Grm,el Study 6/17/2002 35 1.2 year flood 350 _................... ---------- ---- ..-_...._..__....._.._._ .-.... _... ........_ ..., E 300 21.61 m N 250 c 200 L 150 - m 100 , 50 • • 0 0 0.5 1 1.5 2 Shear Stress in Main Channel (lblsq ft) ♦ D50 a D84 Figure 22. Shear Stress and Sediment Size for Cross -Sections Meeting Uniform Flow Criteria. Draft Phase 2 Report —Cedar River Gravel Study 611712002 36 a 1.2 year flood Landsburg Dam 100 90 E 80 LO 70 ..... ..... .... .... ..... ..... ..... .... .... .... ..... .... ..... .... ..... ..... o 60 . . . . . . . . . . . . . . in 9? 50 - . .... 20 40 30 ...... .... .. .... .... .... . .... . ..... ...... .... ..... .... 20 .... a. 10 . . . . . ........ . .... .... ..... .... 0 ..... .. . ..... .... ..... ...... .... ... ..... ..... .. 2* 23.55 21.61 18.55 17.16 16.16 14.91 14.76 14.58 10.87 10.02 5,61 4.70 3.55 2.83 Rver Mile � � .; 1 11711 Figure 23. Predicted Median Grain Size that Would be Mobile During a 1.2-Year Flood for a) Cross Sections that Met Uniform Flow Criteria, and b) All Cross Sections. Draft Phase 2 Report —Cedar River Gravel Study 611712002 37 b 1.5 year flood Landsburg 3.00 Dam CD - E 2.50 E - 2.00 T X, - 0 vi 1.50 FL 1.00 co (n 0.50 . . . . . . . . . . . X 0.00 LU tI)LO 0) t- U) Iq 0) (D (D t- 0 CO 1h N M 0 N 0 W 0 M N V: CR LQ V7 q hOl r,-: LP q "(Pq a! OR q r 11• N P,: M LQ Cq M O M 0 W I- qr'q' V M N N — 0 0 0 W r� 0 V V MN 04 C*4 — — — — — — — — — — — — — — — — — — Rver Mile Figure 24. Excess Shear Stress Ratio During Bankfull Flood for Gravel with a Median Surface Diameter of 40 mm. Initial motion would begin at a ratio of 1.0 and full bed disruption and transport would occur above about 1.3. a) Cross sections that meet uniform flow criteria. b) All cross - sections. Draft Phase 2 Report — Cedar River Gravel Study 611712002 38 4. DISCUSSION 4.1 Effect of Landsburg Dam on Gravel Transport A preliminary assessment of the sediment -trapping potential of the Landsburg diversion dam was made in March 2000 by Inter-Fluve, Incorporated. The conclusions of their thoughtful study are confirmed by this study. Inter-Fluve concluded that the Landsburg Dam has no net effect on gravel transport through the impoundment. Inter-Fluve's findings and conclusions are paraphrased below and discussed in light of this study's findings. Sediment Transport Through the Dam The Taintor gates on Landsburg Dam are opened at flows of about 1,000 to 1,500 cfs. Inter-Fluve's incipient motion analysis using the Shields equation in the vicinity of RM 23.55 predicted that a flow of 1,000 cfs would just begin to mobilize 30 mm gravel, and a flow of 1,500 cfs would initiate transport of 38 mm gravel. This is in agreement with this study's results using the Andrews equation, that 40 min gravel at RM 23.55 would be mobilized at the 1.2-year flood of 1,550 cfs. Gravel beds above the dam are in the 30 to 50 min range. This suggests that whenever flows are large enough to transport gravel the dam gates are opened, allowing sediment to move through. During lower flows when the dam gates are closed, the gravel armor surface of the riverbed would not be mobilized. Sediment transport would be limited primarily to sand and patches of very fine gravel on the channel margins and the bedload transport rate would be low. Figure 25 shows the HEC-RAS shear stress profile upstream from Landsburg Dam for five modeled flood discharges. The exact hydraulics at the dam were not modeled; instead, the first cross-section is located 300 feet upstream in the impoundment. Shear stress of the free -flowing reach upstream of the impoundment (cross-section 23.55) is only slightly larger than the shear stress near the downstream end of the impoundment. Since sediment transport capacity is controlled by shear stress, the rather crude hydraulic model supports the conclusion that bedload sediment from upstream is transported through the pool. Inter-Fluve inspected the riverbed above Landsburg Dam during annual floodway cleaning when water was drained from the impoundment. They inspected and sampled sediment deposits behind the dam, described morphology in the impoundment area and the river section upstream, and interviewed dam operators and other SPU staff regarding dam operation. Geomorphic Evidence Inter-Fluve inspected the riverbed above Landsburg Dam during annual forebay cleaning when water was drained from the impoundment. They inspected and sampled sediment deposits behind the dam, described morphology in the impoundment area and the river Draft Phase 2 Report — Cedar River Gravel Study 611712002 39 section upstream, and interviewed dam operators and other SPU staff regarding dam operation. The backwater pool from the impoundment extends 1/3 of a mile upstream from the dam (ending at cross-section 23.20 of this study). Inter-Fluve reported no evidence of sediment aggradation beyond the channel boundaries. The backwater zone ended at a normal river width at the upstream end with no delta, braiding, gravel deposits or other features that would be associated with aggradation. The backwater pool widens in the downstream direction to two times the normal river width. This was ascribed to the configuration of the diversion dam gates. Within the backwater pool, a gravel bar has formed in the wide channel margin. The bar is submerged during normal operation when the dam gates are closed. The gravel bar volume was estimated at 5,000 cubic yarc s. The bar reportedly was last removed from the channel in 1989. The bar re-formed within the following flood season and reportedly fluctuates in configuration but "overall volume does not vary greatly from year-to-year. This suggests that without bar removal on a yearly basis there is little net trapping of sediment." Inter-Fluve's sources indicated that 1989 was the only time that gravel was actually removed from the impoundment and not returned to the river. t In the 1970s and earlier it was apparently standard practice to bulldoze the bar into the river during the annual forebay cleaning. Inter-Fluve reported no evidence of hydraulic sorting of sediment in the gravel bar. Inter- Fluve's subsurface samples from this bar were analyzed in Phase I of this study by Jones and Stokes (2002). Both surface and subsurface sediment size are very similar at 150 and 400 feet upstream of the dam. The coarsest subsurface sample occurred only 30 feet upstream of the dam. This is the opposite of the trend one would expect if hydraulic sorting and delta growth were occurring, in which case the coarsest sediment would drop out at the upstream end of the impoundment. Inter-Fluve concluded that "The annual sediment supply into the impoundment far exceeds the annual volume changes of the gravel bar... Field observations of the minimal channel instability upstream, downstream, and within the impoundment area, beyond yearly changes in the gravel bar configuration, suggest that there is not a significant yearly :rapping of sediments... Sediment would be expected to accumulate in the impoundment during lower flows when the dam gates are closed and the energy slope is reduced within the impoundment. However, during larger flows when the gates are opened from underneath, detained sediments are apparently flushed under the gates." Hydraulic Calculations Inter-Fluve made hydraulic calculations that indicated that bedload transport capacity is much higher in the steep, narrow channel downstream of Landsburg dam, compared to the low -gradient reach upstream of the dam. Hydraulic and geomorphic differences, rather than trapping of gravel by the dam, were responsible for the lack of gravel on the ' A different source indicates that the bar has been dredged twice in the last twenty years and was last removed in 1985 (Booth, 1992). Draft Phase 2 Report — Cedar River Gravel Study 6/1712002 M bed in the downstream reach. "The downstream reach is capable of moving a particle nearly twice as large as the upstream reach... The downstream reach would act as a transport or erosional reach for particle sizes that may accumulate along the upstream reach." Inter-Fluve's preliminary calculation of sediment transport capacity using the Parker equation yielded a bedload transport capacity of 26,000 cubic yards per year for the reach upstream of the dam (Segment 1 of this study). This was based on IFIM cross-section data rather than the HEC-RAS model used in the present study. Incipient particle motion analyses by Inter-Fluve and the present study show that very little bedload transport would occur at discharges smaller than the 1.2-year flood (1,550 cfs), yet the Parker equation predicted that most of the 26,000 cubic yards would move during flows below 700 cfs when the surface armor layer had not yet broken. The Parker calculation used the top width of the flooded channel rather than the narrower width of the gravel bed. Excluding transport below 700 cfs and using the narrower width yields a bedload transport capacity of approximately 7,000 cubic yards per year. Making a further adjustment based on the somewhat lower slope that was measured in the present study, the calculated transport capacity is reduced to about 5,000 cubic yards per year. This is equal to the volume of the gravel bar in Landsburg pool and the estimated bedload supply rate from erosion processes in the watershed. Bedload transport equations are imprecise and commonly yield results within two to three times the actual rate even when they perform the best. If this lower estimate of 5,000 cubic yards per year is correct, it explains the observation by Inter-Fluve and ourselves that the river shows no sign of sediment deposition or sediment starvation in the reach above Landsburg. The geomorphic observations indicate that amount of available sediment is approximately equivalent to transport capacity. In locations where transport capacity is larger than the 5,000 cubic yards per year of bedload supply, there are geological features in the vicinity of Landsburg that have effectively stabilized the river bed and prevented downcutting (Geomax, 2001). A terminal moraine approximately five miles upstream from Landsburg contains very large boulders that armor the bed. Bedrock crops out in the channel about 11/2 miles downstream from Landsburg. The riverbed '/2 mile downstream from Landsburg has been stable since a gage was installed in 1991, based on rating tables provided by the USGS. The predominant influence of hydraulics on causing the lack of gravel below Landsburg is made even clearer by considering the sources of gravel to the river. The river's gravel supply doubles in Segments 5 and 6, yet spawning gravel abundance remains low for several miles downstream because higher shear stresses and gradients preclude large areas of deposition. Draft Phase 2 Report —Cedar River Grm,e! Study 611712002 41 4.2 Factors Associated with Spawning Gravel Abundance Geomorphic and Hydraulic Factors Extremes of gravel presence or absence in the Cedar River can be adequately explained by geomorphic and hydraulic factors that affect the energy available to transport sediment. Low amounts of available spawning area occur in Se ments 4 to 9 which all have gradients above 0.45% and shear stresses above 1.7 lbs/ft in the 5-year flood. Several of these segments have tightly confined valleys as well. In contrast, the gravel - rich Segment 1 above Landsburg has an average shear stress of 0.9 lb/ft2. Shear stress that low is not found in any other segments of the river, except the Renton Channel (Segment 22). Low gradients and low shear stresses of 1.0 to 1.1 occur in the fairly gravel -rich area of Se ments 19 to 21. However, segments with intermediate shear stress levels (1.1 to 1.4 lb/ft at the 5-year flood) have a wide range of gravel abundance that was not explained by hydraulic or geomorphic variables. As gradient generally declines downstream, the balance between sediment supply and transport capacity shifts, causing gravel deposition and fining of the bed (King County, 1993). King County's 1993 transport modeling and measurements of scour rates, deposition rate and sediment size indicate that the transition from gravel -poor to a consistently gravel -rich state occurs between RM 3 and RM 2 (within Segment 21). Above RM 3, the river has short depositional zones alternating with zones of scour end transport. If sediment supply were to be much larger (as occurred in the 1930s due to accelerated erosion from the Walsh Lake Ditch and widespread timber harvest) the balance would shift. Deposition and active bar formation would once again occur in some segments that are presently transporting all the incoming gravel. Human Modifications The two segments with the highest available spawning area (14 and 19) are the only segments on the river that have a combination of active gravel deposition, perennial side channels and frequent floodplain inundation. Segment 14 also has active channel migration.' These conditions are largely absent in the rest of the Cedar River due to flood control, abundant channel constraints in the form of levees, roads, bridges and natural cliffs, and steep gradients in some segments. Table 6 lists factors that limit the amount of spawning -sized gravels in the Cedar River below Landsburg. Natural geomorphic constraints occur primarily at the upstream end of the river. Human modifications that affect gravel abundance are more widespread. Levees, railroads, and highway embankments artificially confine the river thereby increasing flow depth and (in cases of channel straightening) gradient. The hardened banks prevent channel migration, which is necessary to create gravel bars and side channels that are largely lacking on the Cedar River. Revetments (armored banks without an elevated embankment) also prevent channel migration but they do not prevent floodplain inundation and hence do not affect flow depth. 2 Reach 8, although it has side channels and low confinement, is quite steep and has high shear stress, so the mainstem channel does not have the deposition characteristics necessary for abundant spawning area. Draft Phase 2 Report —Cedar River Gravel Study 611712002 42 Flood control at Chester Morse Lake has probably increased gravel retention in the steeper, upstream part of the study area by reducing the river's transport capacity. The sediment supply was not affected since a natural lake at the dam site trapped gravel from the upper watershed. In the flatter, downstream segments, flood control has reduced the energy available for bank erosion and reduced flood heights so the river rarely accesses its floodplain. The combined effects of flood control and armored banks have resulted in a river that no longer exchanges sediment with its floodplain by eroding banks and depositing new bars. Although some spawning -size gravel occurs in simplified river reaches, it is less abundant than in more naturally -functioning reaches. Flood control and the railroad embankment have been affecting the river since early in the 20'' century. These initial changes caused average total channel width (including vegetated bars and side channels) to drop from 200 feet in 1895 to 179 feet in 1936 (King County, 1993). Between 1936 and 1989, the river narrowed even more to an average width of 110 feet. Most of the narrowing took place by 1970 and was attributed to the stabilizing effect of levees and revetments that were mostly constructed in the 1960s. The reduction in channel width corresponded with loss of major side channels and active gravel bars, resulting in a simplified channel with few active bars. Most of the former bars have become forested with a narrow, sparsely vegetated margin at the river's edge. Draft Phase 2 Report — Cedar River Gravel Study 611712002 43 Figure 25. Shear Stress Profile Upstream from Landsburg Dam, from HEC-RAS model. Station 0 is located about 300 feet upstream from the dam. 3.0 impoundment _ Legend '. - � Shea►(;►,an 1o0-year ` Shear Chen 10-Year --------------- 2 5 ' Shear Chan &Year Shear Chan 1.5-Year -------------- Shear Chan 1.2-Year 2.0 % ` 1.0 0.5 XS 23.55 o.o- --- — — rT- 0 1000� 2000 3000 �— 004 0 5000 Mein Channel Distance (R) Draft Phase 2 Report — Cedar River Gravel Study 611712002 Table 6. Factors that Limit Amount of Spawning -Sized Gravels on the Cedar River. A plus sign indicates that the limitation is particularly severe in that segment. Segment Number Downstream end of Segment (river miles): Geomorphology Human Modifications Gradient too Steep or Flat Valley Wall Confine- ment Levees Railroad, road, bridges Revet- ments Flood Control 4 21 X X X 5 19.098 X X X 6 18 X X 7 16.573 X X+ X 8 15.598 X X 9 14.75 X X X 10 14.064 X X 11 12.138 X+ X 12 11.689 X X 13 11.012 X X 14 10.226 X X 15 9.625 X 16 6.694 X X+ X+ 17 5.21 X X X 18 4.841 X X 19 4.576 X 20 3.25 X X X+ 21 1.633 X X X+ 22 0 X X Draft Phase 2 Report — Cedar River Gravel Studv 611712002 45 4.3 Utilization of Gravels by Salmonids The presence of gravel in the correct size range does not guarantee utilization for spawning. Despite moderate to high amounts of available spawning gravel, steelhead and chinook rarely utilize of gravels downstream of RM 5 (Segments 19 to 22 of this study; see Jones and Stokes, 2002). Steelhead spawn consistently upstream of RM 9, but only occasionally downstream. Chinook spawning is variable between RM 5 and 12 but consistently higher between RM 13 and 19 (Segments 5 to 11). The chinook and steelhead can utilize coarser gravel than sockeye that tend to be smaller. There are no spawning surveys for coho, another small -bodied salmonid that probably spawns mostly in tributary cracks. In 1972, sockeye spawning was heaviest from RM 12 (Segment 11 of this study) upstream to Landsburg. Stober and Graybill (1974) did not count sockeye redds below RM 4.3 (Segments 20 to 22 in this study) due to "very low" utilization despite the presence of gravels with suitable water depth and velocity. They hypothesized that low spawning utilization resulted from reduced intragravel flow in this flatter, depositional reach, exacerbated by fine sediment. Recent sockeye redd counts made in the Renton reach (Segment 22 of this study) in 1998 to 2000 found spawning levels comparable to the 1972 redd counts in the middle and upper river. There are no studies that document recent sockeye utilization above Renton, but anecdotal reports suggest that sockeye spawning is now proportionally higher in the lower river and lower in the upper river, in contrast to Stober and Graybill's findings. The reasons for the apparent change in sockeye utilization areas are unknown. The record high sockeye escapement occurred in 1972, so the declining abundance of fish or other changes to the sockeye population may have affected their spawning preference. Here we consider whether changes in channel morphology or gravel characteristics may have played a role in the apparent change in sockeye utilization. About 150,000 cubic yards of sediment were dredged from the river in Renton in 1972. Stober and Graybill's 1972 survey was presumably done shortly after dredging. Dredging may have initially created a deeper, flatter, slower channel. Smaller dredgings occurred most years from 1976 to 1985. Over 160,000 cubic yards were dredged again in 1998. Since the recent spawning surveys also followed dredging, dredging does not appear to explain recent higher utilization in Renton compared to 1972. Most of the levees and revetments on the Cedar River were constructed in the 1960s. By 1972 the river had already assumed its present morphology: a narrow channel with perennial vegetation growing on former gravel bars. The large sediment supply from the 1920s and 1930s would have moved downstream to below RM 11 by 1972. Hence at least the upstream half of the study area likely had a sediment regime similar to the present. The newly constructed levees had no riparian vegetation, whereas currently most levees have blackberries and a few trees that might provide cover. It is likely that the Draft Phase 2 Report — Cedar River Gravel Studv 611712002 riverbed adjacent to the levees scoured and became coarser, but the timing and amount of scour are unknown. Gravel supply has been fairly steady during the last several decades. The current level of sockeye utilization in the upper river is unknown. There is no evidence that gravel supply or its abundance in the upper river has been reduced since the 1970s when sockeye utilized it heavily. 5. RESTORATION NEEDS AND STRATEGIES Substrate in the medium -gravel to fine -cobble size range suitable for spawning was found in all the surveyed river segments, although the area of suitable substrate was quite small in the steeper segments below Landsburg. The mainstem Cedar River has about 158,500 square yards of wetted spawning gravel from Renton to Landsburg Dam (R2 Resources 2001). The amount of fine sediment in the gravels was generally low and not a limiting factor (see data summary in Jones & Stokes, 2002). Whether existing spawning areas are adequate for existing or anticipated future escapements is beyond the scope of this study. The following recommendations should be implemented as needed. 5.1 Recommended Strategies Levee Removal or Setback Spawning gravel area could be increased by setting back levees that confine and straighten the channel. The resulting drop in shear stress would promote gravel deposition and reduce sediment size. Where channel migration can be restored, the resulting channels would have a diversity of substrate sizes and velocities (for example, Segment 14) compared to rather uniform conditions in the leveed sections. Restoration design should attempt to reproduce confinement and shear stress levels found in reaches with spawning gravel utilization by the desired species. For instance, chinook and steelhead in the Cedar River appear to utilize steeper channels that do not in general have depositional morphology. Some reaches with intermediate gradients and gravel abundance had at least moderate utilization by these large -bodied fish. Segments 14 and 15 (RM 9.6-11) had high available spawning area and were well utilized by steelhead but moderately utilized by chinook. Segment 11 (RM 12-14) had a moderate amount of available gravel and was well utilized by both species. To increase spawning gravel that could be utilized by all species, restoration efforts should focus on the moderate gradient segments (10 to 18) in the middle portion of the study area. Spawning gravel restoration sites in the flatter, lower river would probably be utilized by sockeye but not the other species. Opportunities for levee setback are limited in some river segments due to dense housing (e.g. Dorre Don and Orchard Grove neighborhoods in Segment 7). Excellent Draft Phase 2 Report — Cedar River Gravel Studv 611712002 47 opportunities exist in Segments 11, 12 and 16 where levees protect large tracts of undeveloped floodplain. In the upper river below Landsburg (Segments 4 to 9) there are almost no opportunities for reducing confinement. Shear stress and substrate size would still remain high due to the steep gradient, and little new spawning area would be created. Floodplain Excavation Many floodplains along the river are rarely flooded due to flood control by the upstream dam as well as possible channel incision following levee building. Where this is the case, former side channels rarely are accessed by the river. In some cases fill has been placed to raise the floodplain elevation. High ground that confines the river channel could be excavated to re-establish regular flooding. As with levee removal, the resulting drop in flood depth would promote gravel deposition, reduce sediment size, and in some cases restore the natural pre -dam processes of channel migration and site channel formation. The floodplain should be excavated to a height slightly above the bankfull flood (1.5 year recurrence interval). Former side channels on the floodplain could be excavated to increase their flow. Floodplain excavation may be needed in addition to levee removal at some sites, for instance to remove fill from behind the Ricardi levee at RM 7.5. It could also be implemented as a stand-alone method where the river is confined by high floodplains or terraces. 5.2 Restoration Strategies of Limited Usefulness Gravel Augmentation Gravel augmentation is not recommended because the current gravel supply is what the fish evolved with. The Cedar River still receives gravel from the same watershed area as before dam construction at Cedar Falls and Landsburg. Cliffs downstream of Landsburg continue to supply large amounts of gravel to the river. The gravel -poor reaches below Landsburg have a very high sediment transport capacity. Very high amounts of added gravel would be needed in order to increase gravel area in those reaches. The greatly increased sediment load would likely cause flooding in flatter downstream reaches, where the additional gravel would deposit. The City of Renton is required to place 10,000 cubic yards of gravel in the river at Landsburg over a 10-year period as mitigation for dredging. The first installment of gravel was placed in 2000 in a berm along the right bank just below the Landsburg bridge (Golder, 2000). The placed gravel was dredged from the Renton channel and has an average median diameter of 12 millimeters (1/2 inch). Once mobilized by flood flows, the gravel will move rapidly downstream lue to its small size. Assuming half the added sediment is in a size range suitable for spawning, the addition of 500 cy/year is relatively Draft Phase 2 Report — Cedar River Gravel Study 611712002 small compared to the river's estimated gravel supply of 13,000 cy/year. It is unlikely to increase the area of spawning gravel. Control of Fine Sediment Sources Existing best management practices for sediment control at construction sites should continue to be enforced, but no additional efforts are warranted. Fine sediment levels in Cedar River gravels are well below the NMFS threshold for a properly functioning system. The exception is the Renton Channel (Segment 22), where sand drops out of suspension and becomes a major component of the riverbed. High fine sediment levels are an unavoidable geologic consequence of that segment's flat gradient and position at the bottom of a large watershed. Occasional large landslides from the valley walls in the vicinity of RM 3 to 5 episodically deliver fine sediment to the river. Unlike the cliffs farther upstream whose erosion provides gravel, these cliffs are composed primarily of fine sediment. These landslides occur naturally due to earthquakes and groundwater interactions with the unstable, steep, glacial sediments. Care should be taken to avoid undermining the base of cliffs, discharging surface runoff onto cliffs, or constructing infiltration facilities near the tops of potentially unstable cliffs. Artificial Spawning Channels Constructed side channels that connect to the river only at the downstream end were built in the 1990s for sockeye spawning at RM 4.7 and 4.9. In 2000, the number of sockeye redds in the constructed side channels was about 1/10th the number of redds in the lower 1.64 miles of the mainstem (Jones & Stokes, 2002). In 2001, one of the constructed side channels became the mainstem river after a landslide blocked the former river channel. A replacement spawning channel is planned for a site at RM 3.5. Constructed spawning channels commonly require expensive ongoing maintenance and repairs due to flood damage, unsuitable flood depths or velocities, and sand deposits. Fine sediment deposition is especially likely near the downstream end due to backwater flooding by the river. Most channels have insufficient flow to scour the gravel and keep it clean over the years. Where enough floodplain land is available, a preferable approach is to restore the river's ability to form and maintain gravel -bedded channels. The new mainstem channel at RM 4.7 (Segment 18) is a good example of the types of habitat that can be formed by channel migration. Some spawning was observed there the first winter, and additional spawning area will be formed once the channel widens to its full width and flattens its gradient. The Belmondo reach (RM 10.2 to 11, Segment 14) is another example of an actively migrating channel that provides a variety of habitat functions in addition to spawning gravel for a single species. Spawning channels designed specifically for sockeye should be limited to the lower four miles of river where chinook and steelhead rarely spawn. Upstream of RM 4, restoring natural river processes as recommended in Section 5.1 would likely achieve more net Draft Phase 2 Report — Cedar River Gravel Study 611712002 EEO gain in spawning and rearing habitat for all species. Levee setback could restore larger sections of river for a small portion of the cost of artificial channels. The design of future artificial spawning channels could be greatly improved by incorporating features of natural river morphology (Freeland, 2002). A permeable inlet in the form of an engineered logjam would allow flow to enter over a range of discharges and still protect the inlet from erosion. Other design features could include steeper bank angles, an excavated floodplain along one bank, and clusters of logs with rootwads that are large enough to stay in the channel without anchoring. HEC-6 Sediment Modeling HEC-6 modeling of bedload transport along the Cedar River is not needed to implement the recommendations of this report. 6. CONCLUSIONS Gravel supply to the Cedar River is estimated at about 13,000 cubic yards per year. About 4000 to 5000 cy/yr enters the river above Landsburg. Below Landsburg, about 6500 cy/yr of gravel enters the river from eroding cliffs and landslides and about 1700 cy/yr from tributary creeks. Most of the sediment supply below Landsburg enters the river within the first 6 miles below the diversion dam. The diversion dam at Landsburg shows no evidence of trapping gravel. The dam gates are opened during flows that are large enough to transport gravel, allowing bedload sediment to move through. The high gradient and shear stresses below Landsburg preclude gravel deposition, even though the sediment supply doubles from cliff erosion in the first 4 miles downstream. Low amounts of available spawning area persist for nearly 8 river miles downstream of Landsburg. These ravel -poor segments have gradients above 0.45% and shear stresses above 1.7 lbs/ft in the 5-year flood. In contrast, the gravel -rich channel above the Landsburg pool has a gradient of 0.3% and shear stress of 0.9 lbs/ft2. Shear stress that low is not found in any other river segments except the Renton channel. Gravel supply to the river was higher in the early twentieth century. Gravel supply above Landsburg is likely to drop slightly within the next 15 years due to the cessation of timber harvest in the watershed. This represents a return to lower sediment supply that existed prior to human disturbance of the watershed. Extremes of gravel presence or absence in the Cedar River are related to geomorphology and hydraulics. River segments with high gradients, high shear stresses, and high gradient -confinement indices had low available spawning area (less that 11%) indicating that high value of these parameters are limiting. Segments with over 30% available spawning area had low values of these parameters. In between these extremes, segments Draft Phase 2 Report — Cedar River Gravel Study 611712002 50 showed a wide range of available spawning area that was not explained by any of the morphologic or hydrologic variables. Substrate in the medium -gravel -to -fine -cobble size range suitable for spawning was found in all the surveyed river segments, although the area of suitable substrate was small in the steeper segments below Landsburg Dam. Above River Mile 1, subsurface samples collected within the river channel all had cumulative percentages of sediment finer than 0.85 mm well within the NNE criteria of a properly functioning system. Half the samples below River We 1 had fine sediment levels in excess of the 12 percent criterion (conclusion from Phase 1 report). The two river segments below Landsburg with the highest proportion of available spawning area are the only segments with active gravel deposition, perennial side channels and frequent floodplain inundation. These conditions are absent along most of the river due to flood control, confinement by levees, roads, bridges and cliffs, and steep gradients in some segments. Although the largest amounts of available spawning area occur in depositional zones, Cedar River chinook salmon and steelhead primarily utilize somewhat steeper channels that do not have depositional morphology. Sockeye salmon utilize the Renton channel heavily despite the fine sediment. No recent data are available for sockeye utilization in the rest of the river. The area of gravel in the size range suitable for spawning could be increased by removing levees that confine the channel. The resulting drop in shear stress would promote gravel deposition and reduce sediment size. Where channel migration can be restored, the resulting channels would have a diversity of substrate sizes and velocities. To increase spawning gravel that could be used by all species of salmonids, restoration efforts should focus on segments with moderate gradients in the middle portion of the study area. Excellent opportunities exist in Segments 11, 12 and 16 where levees protect large tracts of undeveloped floodplain. Spawning gravel improvements in the lower river would likely be utilized by sockeye but not other species. Draft Phase 2 Report — Cedar River Grm,el Study 611712002 51 T REFERENCES Andrews, E.D., 1983. Entrainment of gravel from naturally sorted riverbed material. Geological Society of America Bulletin, v. 94, p. 1225-1231. Andrews, E.D., 1984. Bed -material entrainment and hydraulic geometry of Pgravel-bed rivers in Colorado. Geological Society of America Bulletin, v. 95, p. 371-378. Beechie, T., 2001. Empirical predictors of annual bed load travel distance, and implications for salmonid habitat restoration and protection. Earth Surfaces Processes and Landforms volume 26, issue 9. pp 1025-1034. Booth, D.B., 1992, copy of field notes from Landsburg Tour, March 3, 1992, King County Surface Water Management. Booth, D.B., 1995. Surficial Geologic Map of the Maple Valley Quadrangle, King County, Washington. Miscellaneous Field Studies Map M-F2297, U.S. Geological Survey. Booth, D.B., 2000. Geology and geomorphology of stream channels course manual. Subsurface sediment sampling section. University of Washington Engineering Professional Programs, Seattle WA. Booth, D.B., K. Bell and K.X.Whipple, 1991. Sediment Transport Along the South Fork and Mainstem of the Snoqualmie River. King County Surface Water Management Division, Basin Planning Program. Bunte, K., and S.R.Abt, 2001. Sampling Surface and Subsurface Particle -Size Distributions in Wadable Gravel- and Cobble -Bed Streams for Analyses in Sediment Transport, Hydraulics, and Streambed Monitoring. Rocky Mountain Research Station General Technical Report RMRS-GTR-74, Forest Service, United States Department of Agriculture. Burton, K., S. Foley, and B. Mavros, 2000. Cedar River Chinook Salmon (Oncorhynchus tshawytscha) redd survey report, 2000: Spawning habitat characteristics, spatial and temporal redd distributions, and the incidence of spawning sockeye in the vicinity of incubating chinook. Seattle Public Utilities. CES (Cascade Environmental Services, Inc), 1991. Cedar River Instream Flow and Salmonid Habitat Utilization Study, Final Report. Prepared for Seattle Water Department. October. Foster Wheeler, 1995a. Cedar River Watershed Assessment — Basin Condition Reports, Prescriptions, and Restoration Opportunities. Cedar River Watershed Habitat Conservation Plan. Final Report. Prepared for Seattle Water Department by Foster Draft Phase 2 Report — Cedar River Gravel Study 611712002 52 Wheeler Environmental Corporation, Bellevue, Washington; Terrapin Environmental, Duvall, Washington; and Seattle Water Department, Watersheds and Environmental Services, North Bend, Washington. Foster Wheeler, 1995b. Cedar River Watershed Assessment — Mass Wasting and Surface Erosion Assessment. Cedar River Watershed Habitat Conservation Plan. Final Report. Prepared for Seattle Water Department by Foster Wheeler Environmental Corporation, Bellevue, Washington. Freeland, C., 2002. Re: Cedar River Mitigation Channel [email to Noel Gilbrough, US Army Corps of Engineers Seattle District]. Available email: NoeI.L.Gilbroh�a NWS02.usace.armm�.mil Geomax, 2001, Landsburg fish Passage Project Summary Report for the Geomorphic Analysis. Report to MWH Americas from Geomax, Spokane, WA. Golder Associates, 2001. USACE Section 205 Cedar River Flood Damage Reduction Project: Landsburg Gravel Supplementation 2001 Monitoring Results. Prepared for City of Renton — Surface Water Utilities, Renton, Washington. Harza Northwest, Inc., 1992, Reconnaissance Sediment Transport Report for the Cedar River Delta Project, Prepared for the City of Renton. Inter-Fluve, Inc., 2000. Preliminary Assessment of Sediment Trapping Potential of Cedar River Landsburg Diversion. Prepared for Seattle Public Utilities and Duke Engineering & Services by Inter-Fluve, Inc., Hood River, Oregon. Jones and Stokes, 2002. Cedar River Gravel Sudy, Draft Phase 1 Methods and Data Report. Prepared for U.S. Army Corps of Engineers, Seattle District by Jones & Stokes, Bellevue, Washington. King County, 1993. Cedar River Current and Future Conditions Report. Prepared by King County Department of Public Works, Surface Water Management Division, King County, Washington. Kondolf, G.M., and M.G. Wolman, 1993. The Sizes of Salmonid Spawning Gravels. Water Resources Research, volume 29, pp 2275-2285. Miller, D., 2000. Re: Landsburg. [email to Rand Little, Seattle Public Utilities], [Online]. Available email: danmiller(cr�,interfluve.com or appended to Inter-Fluve, 2000. Montgomery Watson Harza,1991. Floodplain/Floodway Study. Produced for Seattle Public Utilities' Landsburg Fish Passage Project. Nelson, L.M., 1971. Sediment transport by streams in the Snohomish River basin, Washington: October 1967-June 1969. USGS Open File Report OF-71-213. Draft Phase 2 Report — Cedar River Gravel Study 611712002 53 Parametrix, 2002. South Fork Tolt River 2001 Sediment Source, LWD, and Channel Survey. Draft Report. Prepared for Seattle City Light and Tolt Fish Advisory Committee by Parametrix, Inc., Kirkland, Washington, and Earth Systems, Monroe, Washington. Perkins, S.J., 1999. Geomorphic evaluation of gravel placement in the Green River, Washington. Perkins Geosciences, report prepared for US Army Corps of Engineers, Seattle District, 52 pp. Petit, F., 1994. Dimensionless critical shear stress evaluation from flume experiments using different gravel beds: Earth Surface Processes and Landforms, v. 19, p. 565- 576. Philips, W.M., 1984. Compilation Geologic Map of the Green River Coal District, King County, Washington. Washington Department of Natural Resources Division of Geology and Earth Resources Open File OF 84-4. R2 Resources, 2001. Level II habitat survey data for the Cedar River from the Landsburg dam to Lake Washington, spring 2000. Provisional data obtained August 2001. Vanoni, V.A. ed., 1975. Sedimentation engineering, American Society of Civil Engineers, New York, NY, 745 pp. Washington Forest Practices Board, 1995. Board Manual: Standard Methodology for Conducting Watershed Analysis Under Chapter 222-22 WAC. Version 3.0. Prepared by Washington Forest Practices Board, Olympia, Washington. Draft Phase 2 Report — Cedar River Gravel Study 611712002 54 APPENDICES Draft Phase 2 Report — Cedar River Gravel Study 611712002 55 Table Al. 1.5-year Flood: Seqment Data Used for Analysis Segment Number Down- stream distance (miles) Estimated local gravel input (cy/yr) Number of HEC-RAS cross- sections (Gradient / Confinement) 1000e Average Energy Gradient (%)e Available Spawning Area (%) Bed Shear Stress, main channel (Ib./ft. z)e Flooded Top Width (ft.)' Confine- ment Ratio`'e Armored bank length (ft.) Unarmored cliff length (ft.) Ratio Armored to Total Bank Length (,6°) Ratio Cliff to Total Bank Length (%)a Total con- strained ratio (°6) 1 23.224 5000 2 2.41 0.4% 0.7 146 1.5 0 800 0 27 27 2 22.608 3 0.70 0.1 % 0.4 166 1.7 300 9 3 22.15 0 4 21 12 8.88 0.8% 2 1.6 90 0.9 3620 5870 60 97 156 5 19.098 4436 20 6.19 0.7% 4 1.4 106 1.1 1100 1830 11 18 29 6 18 1971 13 7.03 0.8% 11 1.6 110 1.1 1950 2180 34 38 71 7 16.573 15 4.91 0.5°6 7 1.2 103 1.0 3970 2880 53 38 91 8 15.598 24 11 3.51 0.6% 8 1.3 172 1.7 4330 0 84 0 84 9 14.75 9 6.21 0.6% 0 1.4 102 1.0 1370 660 31 15 45 10 14.064 291 6 3.40 0.5% 11 1.0 138 1.4 1200 1040 33 29 62 11 12.138 181 20 3.95 0.5% 24 1.1 116 1.2 8090 1170 80 12 91 12 11.689 120 5 2.98 0.4% 7 0.9 124 1.2 450 1980 19 84 103 13 11.012 9 3.71 0.4% 20 1.0 116 1.2 3270 0 91 0 91 14 10.226 9 2.52 0.4% 45 0.9 147 1.5 1740 1040 42 25 67 15 9.625 6 3.01 0.4% 33 1.0 128 1.3 1200 970 38 31 68 16 6.694 2 29 3.49 0.4%. 12 1.0 130 1.2 12580 1400 81 9 90 17` 5.21 17 2.95 0.4% 10 0.9 129 1.2 4250 0 54 0 54 18` 4.841 53 4 2.84 0.5% 22 1.1 185 1.8 1550 0 80 0 80 19` 4.576 53 3 1.16 0.4% 55 0.8 362 3.1 680 440 49 31 80 20 3.25 97 16 3.26 0.3% 22 0.8 115 1.0 4000 2080 57 30 87 21 1.633 42 19 3.30 0.3% 17 0.8 107 0.9 1050 6470 12 76 88 22 0 30 1.15 0.2% 3 0.5 211 1.8 17244 0 200 0 200 Notes: a Cliffs defined as unarmored slopes greater than 10 feet in height and exceeding a 25% angle. Cliffs with bank armoring at the toe were counted as armored banks instead of cliffs. b Sum of cliff and armored bank. Values represent conditions prior to February 2001 landslide. ° Flood top width divided by assumed typical bank full width. e Average of cross section values in segment. EG Segment Analysis do not update link.xlsl .5yr data6/6/2002 Table A2. 5-year Flood: Segment Data Used for Analysis Segment Number Down stream distance (miles) Estimated local gravel nput (cy/yr) Number of HEC-RAS cross- sections (Gradient ! Confinement) `Gradient 1000e Average Energy (°.6)e Available Spawning Area (°6) Bed Shear Stress, main channel 2 (lb./ft.) Flooded Top Width (ft.)' Confine- ment Ratio° a Armored bank length (ft.) Unarmored cliff length (ft.) Ratio Armored to Total Bank Length (%) Ratio Cliff to Total Bank Length % a g ( ) Total con - strained ratio % b ( ) 1 23.224 5000 2 0.98 0.25% 0.9 259 2.6 0 800 0 27 27 2 22.608 3 0.57 0.19% 0.7 334 3.3 300 9 3 22.15 0 4 21 12 7.30 0.73% 2 2.1 99 1.0 3620 5870 60 97 156 5 19.098 4436 20 4.79 0.60% 4 1.8 125 1.2 1100 1830 11 18 29 6 18 1971 13 5.55 0.76% 11 2.1 136 1.4 1950 2180 34 38 71 7 16.573 15 2.87 0.51 % 7 1.7 179 1.8 3970 2880 53 38 91 8 15.598 24 11 1.87 0.83% 8 2.1 442 4.4 4330 0 84 0 84 9 14.75 9 5.08 0.61 % 0 1.9 120 1.2 1370 660 31 15 45 10 14.064 291 6 2.73 0.45% 11 1.3 166 1.7 1200 1040 33 29 62 11 12.138 181 20 2.79 0.46% 24 1.4 164 1.6 8090 1170 80 12 91 12 11.689 120 5 1.53 0.34% 7 1.1 222 2.2 450 1980 19 84 103 13 11.012 9 1.90 0.42% 20 1.3 224 2.2 3270 0 91 0 91 14 10.226 9 0.78 0.40% 45 1.1 515 5.1 1740 1040 42 25 67 15 9.625 6 2.13 0.36% 33 1.2 169 1.7 1200 970 38 31 68 16 6.694 2 29 2.70 0.43% 12 1.3 167 1.6 12580 1400 81 9 90 17e 5.21 17 1.84 0.35% 10 1.2 198 1.9 4250 0 54 0 54 18` 4.841 53 4 1.88 0.50% 22 1.4 278 2.6 1550 0 80 0 80 19` 4.576 53 3 0.82 0.34% 55 1.0 474 4.1 680 440 49 31 80 20 3.25 97 16 2.57 0.31 % 22 1.1 140 1.2 4000 2080 57 30 87 21 1.633 42 19 2.67 0.28% 17 1.1 121 1.1 1050 6470 12 76 88 22 0 30 1.15 0.22% 3 0.8 219 1.9 17244 0 200 0 200 Notes: a Cliffs defined as unarmored slopes greater than 10 feet in height and exceeding a 25% angle. Cliffs with bank armoring at the toe were counted as armored banks instead of cliffs. b Sum of cliff and armored bank. ` Values represent conditions prior to February 2001 landslide. Flood top width divided by assumed typical bank full width. e Average of cross section values in segment. EG Segment Analysis do not update link.xis 5yr Data 6/6/2002 Table A3. 10-year Flood: Segment Data Used for Analysis Segment Number Down- stream distance (miles) Estimated l locagravel input (cy/yr) Number of HEC-RAS cross- sections (Gradient / Confinement) 1000` Average Energy Gradient (,6) ° e Available Spawning Area (%) Bed Shear Stress. main channel (lb./ft.')' Flooded Top Width (ft.)` Confine- ment Ratio° a Armored bank length (ft.) Unarmored cliff length (ft.) Ratio Armored to Total Bank Length (%) Ratio Cliff to Total Bank Length (%)a Total con - strained ratio (°6)e 1 23.224 5000 2 1.22 0.3% 1.2 282 2.8 0 800 0 27 27 2 22.608 3 0.48 0.2% 0.8 375 3.8 300 9 3 22.15 0 4 21 12 6.81 0.7% 2 2.4 103 1.0 3620 5870 3 5 8 5 19.098 4436 20 4.00 0.6% 4 2.1 154 1.5 1100 1830 1 2 3 6 18 1971 13 4.26 0.7% 11 2.4 175 1.7 1950 2180 2 2 4 7 16.573 15 1.96 0.5% 7 1.9 266 2.7 3970 2880 4 3 7 8 15.598 24 11 1.73 0.8% 8 2.3 484 4.8 4330 0 5 0 5 9 14.75 9 2.87 0.6% 0 2.0 199 2.0 1370 660 2 1 2 10 14.064 291 6 0.96 0.5% 11 1.4 478 4.8 1200 1040 2 1 3 11 12.138 181 20 1.72 0.5% 24 1.7 296 3.0 8090 1170 11 2 12 12 11.689 120 5 0.42 0.3% 7 1.2 807 8.1 450 1980 1 3 4 13 11.012 9 1.44 0.4% 20 1.5 298 3.0 3270 0 5 0 5 14 10.226 9 0.80 0.4% 45 1.4 551 5.5 1740 1040 3 2 5 15 9.625 6 1.40 0.3% 33 1.3 244 2.4 1200 970 2 2 4 16 6.694 2 29 2.28 0.4% 12 1.4 197 1.9 12580 1400 25 3 28 17° 5.21 17 1.16 0.3% 10 1.3 315 3.0 4250 0 12 0 12 18° 4.841 53 4 1.22 0.5% 22 1.6 437 4.2 1550 0 6 0 6 19` 4.576 53 3 0.62 0.3% 55 1.1 599 5.2 680 440 3 2 4 20 3.25 97 16 2.29 0.3% 22 1.2 153 1.3 4000 2080 17 9 25 21 1.633 42 19 2.34 0.3% 17 1.2 129 1.1 1050 6470 6 38 44 22 0 30 1.14 0.2% 3 0.9 223 1.9 17244 0 200 0 200 Notes: ° Cliffs defined as unarmored slopes greater than 10 feet in height and exceeding a 25% angle. Cliffs with bank armoring at the toe were counted as armored banks instead of cliffs. b Sum of cliff and armored bank. Values represent conditions prior to February 2001 landslide. ° Flood top width divided by assumed typical bank full width. Average of cross section values in segment. EG Segment Analysis do not update link.xls - 10yr data - 6/6/2002 Table A4. 100-year Flood: Segment Data Used for Analysis Segment Number Down- stream distance (miles) Estimated local gravel input (cy/yr) Number of HEC-RAS cross- sections (Gradient / Confinement) 10001 Average Energy Gradient (%)e Available Spawning Area (%) Bed Shear Stress, main channel (Ib./ft.Z)` Flooded Top Width (ft.)` Confine- ment Ratio"' Armored bank length (ft.) Unarmored cliff length (ft.) Ratio Armored to Total Bank Length (%) Ratio Cliff to Total Bank Length (%)a Total con - strained ratio (%)b 1 23.224 5000 2 0.76 0.3% 1.7 446 4.5 0 800 0 27 27 2 22,608 3 1.01 0.4% 1.8 392 3.9 300 9 3r 22.15 21 3.67 0.6% 158 1.6 4 21 12 5.17 0.6% 2 3.4 125 1.2 3620 5870 3 5 8 5 19.098 4436 20 2.03 0.6% 4 3.0 293 2.9 1100 1830 1 2 3 6 18 1971 13 2.03 0.7 % 11 3.3 361 3.6 1950 2180 2 2 4 7 16.573 15 0.89 0.4% 7 2.3 501 5.0 3970 2880 4 3 7 8 15.598 24 11 0.67 0.6% 8 2.3 932 9.3 4330 0 5 0 5 9 14.75 9 1.11 0.6% 0 2.7 496 5.0 1370 660 2 1 2 10 14.064 291 6 0.69 0.6% 11 2.0 808 8.1 1200 1040 2 1 3 11 12.138 181 20 0.63 0.5% 24 2.4 843 8.4 8090 1170 11 2 12 12 11.689 120 5 0.37 0.5% 7 2.0 1384 13.8 450 1980 1 3 4 13 11.012 9 0.60 0.5% 20 2.2 855 8.5 3270 0 5 0 5 14 10.226 9 0.50 0.4% 45 1.8 842 8.4 1740 1040 3 2 5 15 9.625 6 0.85 0.3% 33 1.9 382 3.8 1200 970 2 2 4 16 6.694 2 29 0.92 0.5% 12 2.1 535 5.1 12580 1400 25 3 28 17` 5.21 17 0.65 0.4% 10 2.0 628 6.0 4250 0 12 0 12 18` 4.841 53 4 0,46 0.5% 22 2.0 1056 10.1 1550 0 6 0 6 19` 4.576 53 3 0.25 0.3% 55 1.3 1165 10.1 680 440 3 2 4 20 3.25 97 16 0.98 0.3% 22 1.7 350 3.0 4000 2080 17 9 25 21 1.633 42 19 1.40 0.3% 17 1.8 209 1.8 1050 6470 6 38 44 22 0 30 1.16 0.2% 3 1.4 243 2.1 17244 0 200 0 200 Notes: a Cliffs defined as unarmored slopes greater than 10 feet in height and exceeding a 25% angle. Cliffs with bank armoring at the toe were counted as armored banks instead of cliffs. b Sum of cliff and armored bank. Values represent conditions prior to February 2001 landslide. Flood top width divided by assumed typical bank full width. ` Average of cross section values in segment. Source: Montgomery Watson Harza, 2001 EG Segment Analysis do not update link.xls - 100yr data - 6/6/2002 Appendix B. Peak Flow Rates Tabulation Upper Cedar River - Above Landsburg Dam 1.2-Year 1.5-Year 5-Year 10-Year 100-Year 2367 1,550 2,030 3,830 4,900 10,300 Middle Cedar River - Maple Valley Golf Course to Landsburg Dam 1.2-Year 1.5-Year 5-Year 10-Year 100-Year 2212.5 1,550 2,030 3,830 4,900 10,300 2041.6 1,640 2,100 3,950 5,050 10,550 1881.2 1,710 2,250 4,110 5,250 10,900 1444.3 1,780 2,375 4,260 5,450 11,250 1210.5 1,800 2,450 4,340 5,550 11,400 678.4 1.870 2,600 4,500 5,750 11,650 Lower Cedar River -- Mouth to Maple Valley Golf Course 1.2-Year 1.5-Year 5-Year 10-Year 100-Year 536.4 1,860 2,600 4,480 5,728 11,660 499.4 1,900 2,650 4,560 5,834 11,830 438.0 1,900 2,650 4,560 5,834 11,300 402.0 1,900 2,650 4,560 5,834 10,200 366.2 1,900 2,650 4,560 5,834 10,750 354.8 1,900 2,650 4,560 5,834 11,300 343.6 1,900 2,650 4,560 5,834 11,450 282.6 1,900 2,650 4,560 5,834 11,830 220.7 1,990 2,700 4,650 5,940 12,000 Flows are applicable to that cross-section and those downstream until next listed cross-section. Peak flow rates analysis by King County is based on Renton and Landsburg gages, 1920-1999. King County provided values for flow variation along the river for the 10-Year and 100-Year Events. 5-Year Event flow rate variation was determined by using the average proportion of the 5-Year to 10-Year Event flow rates based on the two gages (5-Year = 78.2% of 10-Year). 1.5-Year Event flow rates (66.7% exceedence) determined by proportioning between the 80% and 50% exceedence computed values at Renton and Landsburg and then proportioning along the river for flow variation. 1.2-Year Event flow rates (83.3% exceedence) determined by proportioning between the 90% and 80% exceedence computed values at Renton and Landsburg and then proportioning along the river for flow variation. Peak flow values for the 10-Year and 100-Year Events in the Lower Cedar River per City of Renton Study. Peak flow values above Landsburg Dam are per the upper most values in the Middle Cedar River and are based on dam regulation yet the river reach is above the dam. Lowest peak annual floods 1920 to 1999 were 1050 cfs at Landsburg and 1170 cfs at Renton. Table C1. 1.2-Year Flood Cross -Section Data and Calculated Parameters River Mile Segment Q Total (cfs) Maximum Channel Depth (ft) Energy Gradient Slope Water Surface Slope Flooded Width (ft) Channel Shear Stress' (lb/ft') Critical Shear Stress (Ib/ft2) Surface Sediment Size (mm) Predicted Mobile Size ds (mm) Bankfull Width (ft) Bankfull Depth (ft) Available Spawning Area (%)z Confinement Ratio (FW/BW) Maximum Mobile d84 Median d50 d16 23.554 1 1550 4.54 0.16% 0.31 % 171.86 0.64 0.57 54 32 12 36 137.70 2.92 80 1.2 23.248 1 1550 4.61 0.70% 0.30% 110.30 0.49 0.71 186 81 40 10.5 28 112.00 3.80 55 1.0 21.608 4 1550 4.97 0.59% 0.70% 75.46 1.52 1.08 320 61 4.5 86 87.90 4.02 0 0.9 21.261 4 1550 6.30 0.34% 0.46% 70.32 1.22 0.72 160 41 10 69 92.10 3.83 50 0.8 20.493 5 1550 5.11 0.22% 0.29% 120.10 0.67 0.64 85 36 9 38 96.90 3.49 80 1.2 19.865 5 1640 2.57 2.20% 0.62% 103.11 0.76 2.83 300 160 42 43 103.60 2.24 0 1.0 18.546 6 1710 4.40 0.45% 0.68% 106.04 1.44 -1.48 260 150 84 45 81 104.20 3.10 40 1.0 18.145 6 1710 5.79 0.43% 0.61 % 83.52 1.51 0.65 125 57 37 19 85 84.30 4.16 65 1.0 17.592 7 1710 6.03 0.30% 0.45% 80.70 1.17 0.97 270 120 55 20 66 72.20 3.32 50 1.1 17.163 7 1710 5.45 0.32% 0.41 % 73.85 1.10 1.43 310 120 81 38 62 67.00 3.73 10 1.1 16.159 8 1710 5.20 0.56% 0.48% 96.38 0.95 0.92 321 100 52 28 54 66.30 3.75 5 1.5 15.765 8 1710 5.38 0.26% 0.58% 184.25 0.97 1.01 258 113 57 28.5 55 117.00 3.36 60 1.6 14.906 9 1710 4.46 0.53% 0.51 % 101.82 0.96 1.08 450 160 61 32 54 99.10 3.11 25 1.0 14.757 9 1710 4.34 0.47% 0.42% 97.62 0.87 1.06 390 113 60 31 49 92.40 2.52 75 1.1 14.575 10 1710 5.52 0.33% 0.42% 177.64 0.69 0.64 320 101 36 14 39 89.60 2.92 60 2.0 14.012 11 1780 3.90 0.56% 0.52% 111.28 0.96 0.97 315 110 55 13 54 115.40 3.22 65 1.0 13.208 11 1780 4.34 0.63% 0.48% 95.63 0.94 0.76 205 67 43 19 53 96.30 3.42 50 1.0 12.666 11 1780 5.26 0.47% 0.38% 77.23 0.93 1.40 205 110 79 49 52 83.80 3.05 35 0.9 12.054 12 1800 6.36 0.33% 0.40% 120.43 0.83 0.55 130 57 31 14 47 81.50 3.78 75 1.5 11.366 13 1800 3.03 1.49% 0.50% 105.79 0.71 0.69 260 65 39 18 40 100.80 1.80 85 1.0 10.942 14 1800 7.22 0.29% 0.32% 78.75 0.88 0.53 167 75 30 10 50 70.00 3.81 65 1.1 10.865 14 1800 5.04 0.38% 0.35% 93.74 0.80 0.97 210 91 55 24 45 92.20 3.92 70 1.0 10.017 15 1800 5.20 0.18% 0.26% 112.01 0.68 1.59 260 150 90 32 39 100.00 2.02 30 1.1 9.252 16 1800 3.66 0.40% 0.42% 123.24 0.81 0.85 250 100 48 46 115.70 2.37 40 1.1 8.193 16 1800 5.04 0.57% 0.50% 90.46 1.04 0.69 260 110 39 3 59 3. 60 1.2 7.395 16 1800 5.46 0.77% 0.53% 87.00 1.04 0.71 280 80 40 18 59 95.90 95.90 3.56 70 . 6.216 17 1870 4.57 0.38% 0.40% 170.35 0.66 1.24 360 150 70 24 37 105.80 2.40 25 1 .6 5.613 17 1870 4.10 0.45% 0.34% 102.40 0.72 0.74 190 102 42 22 41 98.90 2.05 85 1.0 4.702 19 1900 3.45 0.45% 0.45% 362.59 0.66 0.62 220 88 35 4 37 143.70 2.32 60 2.5 4.38 20 1900 4.03 0.57% 0.39% 179.36 0.48 1.06 200 110 60 7 27 180.80 1.59 40 1.0 3.548 20 1900 3.55 0.38% 0.31 % 115.57 0.56 0.51 150 57 29 4 32 115.00 2.40 75 1.0 2.286 21 1900 3.83 1.09% 0.25% 91.47 0.49 0.78 180 81 44 24 1 28 87.50 3.58 75 1.0 ' Shear Stress was calculated using water surface gradient. 2 Available spawning area is a visual estimate of the area bisected by channel cross-section, with width equal to wetted width and length equal to two times the bankfull width. Table C2. 1.5-Year Flood Cross -Section Data and Calculated Parameters River Maximum Energy Water Flooded Channel Critical Predicted Bankfull Bankfull Available Confinement Q Total Channel Gradient Surface Shear Shear Surface Sediment Size (mm) Mobile Width Depth Spawning Ratio Mile Segment Depth Slope Slope Width Stress' Stress Size Area (cfs) (ft) (ft) (lb/ft2) (lb/ft2) ds (mm) (ft) (ft) (%)2 (FW/BW) Maximum Median Mobile d84 d50 d16 23,554 1 2030 5.09 0.17% 0.30% 180.25 0.69 0.57 54 32 12 39 137.70 2.92 80 1.3 23.248 1 2030 5.38 0.53% 0.29% 111.36 0.59 0.71 186 81 40 10.5 33 112.00 3.80 55 1.0 21.608 4 2030 5.68 0.59% 0.72% 80.04 1.77 1.08 320 61 4.5 100 87.90 4.02 0 0.9 21.261 4 2030 6.99 0.38% 0.47% 73.82 1.37 0.72 160 41 10 77 92.10 3.83 50 0.8 20.493 5 2030 5.77 0.23% 0.30% 126.60 0.76 0.64 85 36 9 43 96.90 3.49 80 1.3 19.865 5 2100 2.94 2.09% 0.62% 105.34 0.88 2.83 300 160 42 50 103.60 2.24 0 1.0 18.546 6 2250 5.07 0.45% 0.69% 109.55 1.71 1.48 260 150 84 45 97 104.20 3.10 40 1.1 18.14 6 2250 6.42 0.47% 0.62% 85.92 1.71 0.65 125 57 37 19 97 84.30 4.16 65 1.0 17.592 7 2250 6.81 0.31 % 0.44% 83.89 1.30 0.97 270 120 55 20 73 72.20 3.32 50 1.2 17.163 7 2250 6.17 0.35% 0.42% 76.35 1.29 1.43 310 120 81 38 73 67.00 3.73 10 1.1 16.159 8 2250 5.95 0.66% 0.50% 154.73 0.84 0.92 321 100 52 28 47 66.30 3.75 5 2.3 15.765 8 2250 5.88 0.26% 0.55% 186.97 1.09 1.01 258 113 57 28.5 61 117.00 3.36 60 1 1.6 14.906 9 2250 5.08 0.52% 0.50% 103.98 1.12 1.08 450 160 61 32 63 99.10 3.11 25 1.0 14.757 9 2250 4.97 0.48% 0.43% 100.94 1.01 1.06 390 113 60 31 57 92.40 2.52 75 1.1 14.575 10 2250 5.97 0.34% 0.43% 180.33 0.79 0.64 320 101 36 14 45 89.60 2.92 60 2.0 14.012 11 2375 4.65 0.50% 0.50% 116.09 1.11 0.97 315 110 55 13 63 115.40 3.22 65 1.0 13.208 11 2375 4.91 0.66% 0.49% 105.87 1.10 0.76 205 67 43 19 62 96.30 3.42 50 1.1 12.666 11 2375 6.11 0.47% 0.39% 81.91 1.08 1.40 205 110 79 49 61 83.80 3.05 35 1.0 12.054 12 2450 7.07 0.35% 0.39% 129.74 0.92 0.55 130 57 31 14 52 81.50 3.78 75 1.6 11.366 13 2450 3.78 1.17% 0.51 % 114.85 0.90 0.69 260 65 39 18 51 100.80 1.80 85 1.1 10.942 14 2450 8.22 0.31 % 0.32% 85.70 0.99 0.53 167 75 30 10 56 70.00 3.81 65 1.2 10.865 14 2450 6.05 0.37% 0.35% 108.96 0.89 0.97 210 91 55 24 50 92.20 3.92 70 1.2 10.017 15 2450 6.08 0.19% 0.27% 123.52 0.77 1.59 260 150 90 32 44 100.00 2.02 30 1.2 9.252 16 2450 4.32 0.40% 0.41 % 125.59 0.93 0.85 250 100 48 8 53 115.70 2.37 40 1.1 8.193 16 2450 5.78 0.56% 0.49% 91.95 1.21 0.69 260 110 39 3 69 75.00 3.73 60 1.2 7.395 16 2450 6.36 0.66% 0.52% 92.36 1.23 0.71 280 80 40 18 69 95.90 3.56 70 1.0 6.216 17 2600 5.50 0.40% 0.39% 256.39 0.61 1.24 360 150 70 24 35 105.80 2.40 25 2.4 5.613 17 2600 5.19 0.36% 0.29% 105.17 0.78 0.74 190 102 42 22 44 98.90 2.05 85 1.1 4.702 19 2650 3.92 0.45% 0.43% 384.37 0.74 0.62 220 88 35 4 42 143.70 2.32 60 2.7 4.38 20 2650 4.93 0.34% 0.32% 203.31 0.52 1.06 200 110 60 7 29 180.80 1.59 40 1.1 3.548 20 26501 4.45 0.31 % 0.30%1 120.29 0.67 0.51 150 57 29 4 38 115.00 2.40 75 1.0 2.826 21 2650 4.93 0.90% 0.26% 94.53 0.66 0.78 180 81 44 24 37 87.50 3.58 75 1.1 Shear Stress was calculated using water surface gradient. 2 Available spawning area is a visual estimate of the area bisected by channel cross-section, with width equal to wetted width and length equal to two times the bankfull width. Table C3. 5-Year Flood Cross -Section Data and Calculated Parameters River Maximum Energy Water Flooded Channel Critical Predicted Bankfull Bankfull Available Confinement Q Total Channel Gradient Surface Width Shear Shear Surface Sediment Size (mm) Mobile Width Depth Spawning Ratio Mile Segment Depth Slope Slope Stress' Stress Size Area (cfs) (ft) (ft) (Ib/ftz) (Ib/ft2) ds (mm) (ft) (ft) (%)Z (FW/BW) Maximum Median Mobile d84 d50 d16 23.554 1 3830 6.78 0.19% 0.26% 238.79 0.84 0.57 54 32 12 47 137.70 2.92 80 1.7 23.248 1 3830 7.78 0.32% 0.26% 279.18 0.88 0.71 186 81 40 10.5 50 112.00 3.80 55 2.5 21.608 4 3830 7.54 0.60% 0.76% 88.88 2.65 1.08 320 61 4.5 150 87.90 4.02 0 1.0 21.261 4 3830 9.04 0.46% 0.48% 82.66 1.81 0.72 160 41 10 102 92.10 3.83 50 0.9 20.493 5 3830 7.79 0.24% 0.27% 135.40 0.98 0.64 85 36 9 55 96.90 3.49 80 1.4 19.865 5 3950 4.60 1.28% 0.58% 115.50 1.32 2.83 300 160 42 75 103.60 2.24 0 1.1 18.546 6 j 4110 6.97 0.42% 0.72% 119.66 2.47 1.48 260 150 84 45 140 104.20 3.10 40 1.1 18.14 6 4110 8.20 0.59% 0.56% 128.28 2.30 0.65 125 57 37 19 130 84.30 4.16 65 1.5 17.592 7 4110 8.87 0.34% 0.45% 184.02 1.68 0.97 270 120 55 20 95 72.20 3.32 50 2.5 17.163 7 4110 7.58 0.38% 0.37% 369.52 1.39 1.43 310 120 81 38 79 67.00 3.73 10 5.5 16.159 8 4110 6.28 1.53% 0.68% 155.58 1.29 0.92 321 100 52 26 73 66.30 3.75 5 2.3 15.765 8 4110 7.31 0.20% 0.48% 645.35 1.32 1.01 258 113 57 28.5 75 117.00 1 3.36 60 5.5 14.906 9 4110 6.93 0.48% 0.50% 110.47 1.58 1.08 450 160 61 32 89 3.11 25 1.1 14.757 9 4110 6.66 0.55% 0.42% 160.81 1.23 1.06 390 113 60 31 70 2.52 75 1.7 14.575 10 4110 7.17 0.38% 0.42% 187.66 1.05 0.64 320 101 36 14 60 E9.6 2.92 60 2.1 14.012 11 4260 6.68 0.39% 0.49% 129.13 1.57 0.97 315 110 55 13 89 3.22 65 1.113.208 11 4260 6.44 1.19% 0.57% 214.78 1.06 0.76 205 67 43 19 60 3.42 50 2.2 12.666 11 4260 8.02 0.41 % 0.38% 375.28 1.34 1.40 205 110 79 49 76 83.80 3.05 35 4.5 12.054 12 4340 8.65 0.37% 0.39% 140.60 1.19 0.55 130 57 31 14 67 81.50 3.78 75 1.7 11.366 13 4340 5.41 0.91 % 0.56% 134.71 1.37 0.69 260 65 39 18 77 100.80 1.80 85 1.3 10.942 14 4340 9.58 0.25% 0.26% 902.48 0.99 0.53 167 75 30 10 56 70.00 3.81 65 12.9 10.865 14 4340 7.54 0.35% 0.43% 774.90 1.40 0.97 210 91 55 24 79 92.20 3.92 70 8.4 10.017 15 4340 8.01 0.22% 0.26% 272.59 0.87 1.59 260 150 90 32 49 100.00 2.02 30 2.7 9.252 16 4340 5.90 0.42% 0.40% 137.15 1.21 0.85 250 48 8 68 115.70 2.37 40 1.3 8.193 16 4340 7.55 0.56% 0.50% 95.47 1.69 0.69 260 �80 39 3 96 75.00 3.73 60 1.3 7.395 16 4340 8.83 0.59% 0.55% 162.08 1.35 0.71 280 40 18 77 95.90 3.56 70 1.0 6.216 17 4500 7.04 0.26% 0.32% 318.72 0.69 1.24 360 150 70 24 39 105.80 2.40 25 3.0 17 4500 6.79 0.41 % 0.31 % 109.23 1.09 0.74 190 102 42 22 62 98.90 2.05 85 1.1 5.613 4560 5.04 0.39% 0.39% 527.39 0.89 0.62 220 88 35 4 51 143.70 2.32 60 3.7 4.702 19 4.38 20 4560 7.05 0.15% 0.18% 220.32 0.50 1.06 200 110 60 7 28 180.80 1.59 40 1.2 3.548 20 4560 6.38 0.24% 0.27% 126.24 0.89 1 0.51 150 57 29 4 51 115.00 2.40 75 1.1 2.826 21 4560 7.41 0.71 % 0.26% 101.88 0.97 0.78 180 81 44 24 55 87.50 3.58 75 1.2 ' Shear Stress was calculated using water surface gradient. 2 Available spawning area is a visual estimate of the area bisected by channel cross-section, with width equal to wetted width and length equal to two times the Bankfull width. Table C4. 10-Year Food Cross -Section Data and Calculated Parameters River Mile Segment Q Total (cfs) Maximum Channel Depth (ft) Energy Gradient Slope Water Surface Slope Flooded Width (ft) Channel Shear Stress' (Ib/ft2) Critical Shear Stress (lb/ft') Surface Sediment Size (mm) Predicted Mobile Size ds (mm) Bankfull Width (ft) Bankfull Depth (ft) Available Spawning Area (/o)2 Confinement Ratio (FW/BW) Maximum Mobile d84 Median d50 d16 23.554 1 4900 7.76 0.18% 0.31 % 280.68 1.20 0.57 54 32 12 68 137.70 2.92 80 2.0 23.248 1 4900 7.82 0.51 % 0.27% 282.50 0.93 0.71 186 81 40 10.5 52 112.00 3.80 55 2.5 21.608 4 4900 8.42 0.61 % 0.78% 92.64 3.15 1.08 320 61 4.5 178 87.90 4.02 0 1.1 21.261 4 4900 10 0.50% 0.49% 86.36 2.04 0.72 160 41 10 115 92.10 3.83 50 0.9 20.493 5 4900 8.68 0.25% 0.28% 138.62 1.11 0.64 85 36 9 63 96.90 3.49 80 1.4 19.865 5 5050 5.51 1.07% 0.58% 121.59 1.56 2.83 300 160 42 88 103.60 2.24 0 1.2 18.546 6 5250 7.88 0.43% 0.70% 130.44 2.77 1.48 260 150 84 45 157 104.20 3.10 40 1.3 18.14 6 5250 9.1 0.65% 0.73% 206.26 2.64 0.65 125 57 37 19 150 84.30 4.16 65 2.4 17.592 7 5250 9.81 0.35% 0.50% 243.93 2.11 0.97 270 120 55 20 119 72.20 3.32 50 3.4 17.163 7 5250 8.26 0.39% 0.35% 373.25 1.44 1.43 310 120 81 38 82 67.00 3.73 10 5.6 16.159 8 5250 6.46 2.08% 0.45% 156.04 0.89 0.92 321 100 52 28 50 66.30 3.75 5 2.4 15.765 8 5250 7.16 0.47% 0.53%1 234.54 1.42 1.01 258 113 57 28.5 80 117.00 3.36 60 2.0 14.906 9 5250 7.8 0.48% 0.51 % 143.91 1.82 1.08 450 160 61 32 103 99.10 3.11 25 1.5 14.757 9 5250 7.47 0.58% 0.36% 179.17 1.15 1.06 390 113 60 31 65 92.40 2.52 75 1.9 14.575 10 5250 7.7 0.30% 0.36% 1,398.45 1.02 0.64 320 101 36 14 58 89.60 2.92 60 15.6 14.012 11 5450 7.72 0.35% 0.48% 529.63 1.81 0.97 315 110 55 102 115.40 3.22 65 4.6 13.208 11 5450 7.17 0.95% 0.55% 220.77 1.22 0.76 205 67 43 69 96.30 3.42 50 2.3 12.666 12 5450 8.86 0.32% 0.33% 1,131.85 1.35 1.40 205 110 79 r49 76 83.80 3.78 35 135 12.054 12 5550 8.21 0.79% 0.30% 137.57 0.86 0.55 130 57 31 49 81.50 3.78 75 1.7 11.366 13 5550 6.16 0.86% 0.62% 146.12 1.75 0.69 260 65 39 99 100.80 1.80 85 1.4 10.942 14 5550 10.16 0.25% 0.23% 920.90 0.93 0.53 167 75 30 10 53 70.00 3.81 65 13.2 10.865 14 5550 8.24 0.32% 0.45% 802.63 1.65 0.97 210 91 55 24 94 92.20 3.92 70 8.7 10.017 15 5550 8.78 0.23% 0.23% 357.0 00.90 1.59 260 150 90 32 51 100.00 2.02 30 3.6 9.252 16 5550 6.75 0.46% 0.39% 155.131 1.25 0.85 250 100 48 8 70 115.70 2.37 40 1.3 8.193 16 5550 8.5 0.57% 0.50% 97.36 1.94 0.69 260 110 39 3 110 75.00 3.73 60 1.3 7.395 6.216 5.613 4.702 4.38 3.548 2.826 17 17 19 19 20 20 21 5550 5750 5750 5834 5834 5834 5834 9.99 8.16 7.54 5.71 8.27 7.44 9.9 0.49% 0.18% 0.46% 0.34% 0.11 % 0.22% 0.47% 0.56% 0.26% 0.32% 0.38% 0.15% 0.27% 0.24% 198.53 331.80 111.14 579.96 229.05 128.91 110.381 1.49 0.71 1.25 1.00 0.52 1.03 1.17 0.71 1.24 0.74 0.62 1.06 0.51 0.78 280 360 190 220 200 150 180 80 150 102 88 110 57 81 40 70 42 35 60 29 44 18 24 22 4 7 4 24 85 40 71 57 29 58 66 95.90 105.80 98.90 143.70 180.80 115.00 87.50 3.56 2.40 2.05 2.32 1.59 2.40 3.58 70 25 85 60 40 75 75 2.1 3.1 1.1 4.0 1.3 1.1 1.3 ' Shear Stress was calculated using water surface gradient. 2 Available spawning area is a visual estimate of the area bisected by channel cross-section, with width equal to wetted width and length equal to two times the bankfull width. Table C5. 100-Year Flood Cross -Section Data and Calculated Parameters River Maximum Energy Water Flooded Channel Critical Predicted Bankfull Bankfull Available Confinement Q Total Channel Gradient Surface Shear Shear Surface Sediment Size (mm) Mobile Width Depth Spawning Ratio Mile Segment Depth Slope Slope Width Stress' Stress Size Area (cfs) (ft) (ft) (lb/ft') (Ib/ft2) ds (mm) (ft) (ft) (%)Z (FW/BW) Maximum Median Mobile d84 d50 d16 23.554 1 10300 10.52 0.20% 0.32% 346.25 1.75 0.57 54 32 12 99 137.70 2.92 80 2.5 23.248 1 10300 10.49 0.48% 0.24% 544.77 1.21 0.71 186 81 40 69 112.00 3.80 55 4.9 21.608 4 10300 11.75 0.67% 0.86% 106.81 5.20 1.08 320 61 294 87.90 4.02 0 1.2 21.261 4 10300 13.47 0.62% 0.57% 95.27 3.18 0.72 160 41 E42 180 92.10 3.83 50 1.0 20.493 5 10300 10.77 0.50% 0.50% 154.88 2.38 0.64 85 36 134 96.90 3.49 80 1.6 19.865 5 10550 8.83 0.80% 0.60% 144.34 2.47 2.83 300 160 139 103.60 2.24 0 1.4 18.546 6 10900 8.67 1.27% 0.81 % 140.88 3.53 1.48 260 150 84 45 200 104.20 3.10 40 1.4 18.14 6 10900 12.44 0.47% 0.76% 332.54 4.32 0.65 125 57 37 19 244 84.30 4.16 65 3.9 17.592 7 10900 12.1 0.48% 0.60% 324.46 3.25 1 0.97 270 120 55 20 184 72.20 3.32 50 4.5 17.163 7 10900 10.75 0.40% 0.43% 380.56[2.20 1.43 310 120 81 38 132 67.00 3.73 10 5.7 16.159 8 10900 8.39 1.00% 0.45% 780.19 0.92 321 100 52 28 71 66.30 3.75 5 11.8 15.765 8 10900 8.66 0.45% 0.56% 794.14 1.01 258 113 57 28.5 113 117.00 3.36 60 6.8 14.906 9 10900 9.71 0.50% 0.46% 794.28 1.08 450 160 61 32 122 99.10 3.11 25 8.0 14.757 9 10900 10.12 0.41 % 0.49% 760.67 1.06 390 113 60 31 124 92.40 2.52 75 8.2 14.575 10 10900 10.33 0.19% 0.49% 1,824.41 0.64 320 101 36 14 122 89.60 2.92 60 20.4 14.012 11 11250 11.89 0.25% 0.81% 740.40 0.97 315 110 55 13 286 115.40 3.22 65 6.4 13.208 11 11250 9.78 0.11% 0.36% 2,009.62 0.76 205 67 43 19 77 96.30 3.42 50 20.9 12.666 11 11250 11.53 0.14% 0.22% 1,831.26 1.40 205 110 79 49 72 83.80 3.05 35 21.9 12.054 12 11400 9.56 1.49% 0.71 % 166.69 2.53 0.55 130 57 31 14 143 81.50 3.78 75 2.0 11.366 13 11400 7.54 0.80% 0.48% 898.09 1.70 0.69 260 65 39 18 96 100.80 1.80 85 8.9 10.942 14 11400 12.14 0.26% 0.43% 1,178.65 2.21 0.53 167 75 30 10 125 70.00 3.81 65 16.8 10.865 14 11400 8.77 0.89% 0.49% 812.38 1.93 0.97 210 91 55 24 109 92.20 3.92 70 8.8 10.017 15 11400 12.37 0.17% 0.18% 470.10 1.11 1.59 260 150 90 32 63 100.00 2.02 30 4.7 9.252 16 11400 9.09 0.51 % 0.41 % 328.81 1.84 0.85 250 100 48 8 104 115.70 2.37 40 2.8 8.193 16 11400 10.99 0.85% 0.63% 127.73 3.19 0.69 260 110 39 3 180 75.00 3.73 60 1.7 7.395 16 11400 14.02 0.22% 0.56% 850.95 2.62 0.71 280 80 40 18 148 95.90 3.56 70 8.9 6.216 17 11650 11.68 0.11 % 0.16% 395.75 0.76 1.24 360 150 70 24 43 105.80 2.40 25 3.6 5.613 17 11650 9.18 0.92% 0.52% 153.78 2A5 0.74 190 102 42 22 139 98.90 2.05 85 1.6 4.702 19 11830 8.29 0.23% 0.29% 1,322.42 1.24 0.62 220 88 35 4 70 143.70 2.32 60 9.2 4.38 20 11300 11.85 0.08 0 0.16% 871.59 0.83 1.06 200 110 60 7 47 180.80 1.59 40 4.8 3.548 20 11300 11.75 0.28% 027% 153.91 1.49 0.51 150 57 29 4 84 115.00 2.40 75 1.3 15.47 0.51 % 0..26% 133.86 1.81 0.78 180 81 44 24 102 87.50 3.58 75 1.5 2.826 21 11830 ' Shear Stress was calculated using water surface gradient. 2 Available spawning area is a visual estimate of the area bisected by channel cross-section, with width equal to wetted width and length equal to two times the bankfull width. r Appendix D: Proportion of surface sediment samples in size ranges preferred for spawning on the Cedar River Segment % of sample in size % of sample in size Number Description River Mile range range 13 mm to 152 mm' 38 mm to 152 mmz 1 XS, no margin 23.553 85.8% 35.0% 1 XS, no margin 23.248 82.0% 50.3% 4 XS, complete 21.61 35.9% 19.2% 4 XS, complete 21.261 66.1 % 35.2% 5 XS, complete 20.493 74.2% 40.4% 5 XS, complete 19.865 41.0% 33.0% 6 XS, complete 18.546 80.8% 68.6% 6 XS, no margin or thalweg 18.145 92.2% 44.6% 7 XS, complete 17.592 77.3% 53.3% 7 XS, complete 17.163 85.6% 71.6% 8 XS, complete 16.159 89.0% 62.6% 8 Dorre Don side channel 15.869 84.9% 36.9% 8 XS, complete 15.765 84.8% 60.6% 9 XS, complete 14.906 73.3% 58.5% 9 XS, complete 14.757 83.4% 60.9% 9 Low bench at XS margin 14.757 91.8% 48.0% 10 XS, complete 14.575 78.6% 39.4% 11 XS, complete 14.012 77.5% 55.9% 11 XS, no thalweg 13.208 89.3% 55.5% 11 XS, no thalweg 12.666 90.3% 79.3% 12 XS, no margin 12.054 88.3% 34.4% 13 XS, complete 11.366 87.0% 49.3% 14 XS, no thalweg 10.942 81.9% 39.7% 14 Low lateral bench 10.942 74.5% 25.0% 14 XS, complete 10.865 86.0% 70.9% 15 XS, complete 10.017 76.9% 67.0% 16 XS, w/ thalweg (50') 9.252 69.8% 51.4% 16 XS, top of berm (18') 9.252 86.5% 51.1 % 16 XS, no thalweg 8.193 67.5% 40.0% 16 XS, no thalweg 7.395 86.2% 49.2% 17 500 ft u/s of 6.216 in segment (ASA -95%) 6.311 93.2% 50.7% 17 XS, no thalweg (ASA -25%) 6.216 76.4% 56.1 % 17 XS, complete 5.613 90.5% 46.3% 19 XS, no margin 4.702 70.3% 46.0% 20 XS, no margin 4.38 75.6% 58.7% 20 XS, no margin 3.548 76.9% 36.1 % 21 XS, complete 2.809 92.7% 58.7% ' Preferred size range for Sockeye, Steelhead, Chinook and Coho (CES, 1991) 2 Preferred size range for Chinook (Burton et al., 2000) Size Range.xls Jones Stokes April 19, 2002 Mr. Jeffrey F. Dillon U.S. Army Corps of Engineers Seattle District P.O. Box 3755 Seattle, WA 98124-3755 RECEIVED APR 2 2 2UJ2 CITY OF RENTON UTILITY SYSTEMS SUBJECT: Draft Report for Task Order #10, Cedar River Gravel Study Phase 1, Contract No. DACW-67-00-D- 10 11 Dear Jeff: We are pleased to submit the review draft of the Phase 1 data report for the Cedar River Gravel Study. The report documents the study methodology and summarizes the results of literature reviews and data collection involving channel cross sections, surface and subsurface gravel sampling, spawning history and fish habitat, and fine sediment. Many of these data and hydraulic data generated from HEC-RAS modeling will be used in Phase 2 analyses to relate the scour potential of the channel to particle size distributions of bed material at select locations along the Cedar River. As you know, Harper, Houf, and Righellis has completed most of the HEC-RAS modeling, and Perkins Geosciences has commenced with gravel movement calculations. However, your input and the input of project sponsors is important to assuring that Phase 2 analyses address the study objectives. Please review the enclosed report as it presents many of the data that will affect Phase 2 results. By way of a copy of this letter, I am also requesting that project sponsors review the Phase 1 report and provide you with comments and proposed revisions within approximately 2 weeks of receipt of the report. I understand you will then compile the comments and forward them to me for incorporation in the final Phase 1 report. I will also coordinate with Sue Perkins to assure any concerns are addressed during Phase 2 analyses and reporting. I anticipate that changes to the final Phase 1 report will primarily be made to the report text and incorporated tables. I ask all reviewers to keep the appendices, maps, photos, and report binder because the final report will probably be submitted as replacement pages for the text and tables. 11820 Northup Way, Suite E300 • Bellevue, WA 98005-1946 • tel. 425 822.1077 • fax 425 822.1079 www.jonesandstokes.com Mr. Jeffrey F. Dillon April 18, 2002 Page 2 I trust you will find the report in order. Please call me during the review period if you have questions. I can be reached at 425-893-6433 or by email at mwolanek@jsanet.com. Sincerely, rw 1 * Lj b Michael D. Wolanek Hydrologist :lr Enclosure cc: Rand Little, Seattle Public Utilities Gary Schimek, City of Renton Deb Lester, King County Larry Fisher, Washington Department of Fish and Wildlife Sue Perkins, Perkins Geosciences o,O0t.o1 USACE/CEDAR RIVER GRAVEL 04/ I8/02e 11820 Northup Way, Suite E300 • Bellevue, WA 98005-1946 • tel. 425 822.1077 • fax 425 822.1079 www.ionesandstokes.com Draft Phase I Methods and Data Report Cedar River Gravel Study Prepared for: U.S. Army Corps of Engineers Seattle District 4735 East Marginal Way South P.O. Box 3755 Seattle, Washington 98124 Prepared by: R Jones & Stokes 11820 Northup Way, Suite E300 Bellevue, Washington 98005-1946 425/822-1077 April 2002 This document should be cited as: Jones & Stokes. 2002. Cedar River Gravel Study. Draft phase 1 methods and data report. April. (J&S OJO10.01.) Bellevue, WA. Prepared for U.S. Army Corps of Engineers, Seattle District, Seattle, WA. • Table of Contents 1 INTRODUCTION..................................................... 1.1 Project Overview ............................................. 1.2 Overview of Report ......................................... .......................................................1 .......................................................1 .......................................................2 2 STUDY APPROACH............................................................................................................2 2.1 Phase 1 Work Activities..............................................................................................2 2.2 Site Selection...............................................................................................................3 2.3 Referencing Data to Locations along the Cedar River................................................4 2.3.1 River Miles...................................................................................................4 2.3.2 Study Segments............................................................................................4 3 FIELD DATA COLLECTION METHODS.......................................................................5 3.1 Cross Sections.............................................................................................................5 3.1.1 Scope of Work.............................................................................................5 3.1.2 Data Sources................................................................................................5 3.1.3 Methods........................................................................................................5 3.2 Surface Gravel.............................................................................................................9 3.2.1 Scope of Work.............................................................................................9 3.2.2 Data Sources................................................................................................9 3.2.3 Methods......................................................................................................10 3.3 Subsurface Gravel.....................................................................................................11 3.3.1 Scope of Work...........................................................................................11 3.3.2 Data Sources..............................................................................................11 3.3.3 Methods......................................................................................................11 3.4 Fine Sediment............................................................................................................12 3.4.1 Scope of Work...........................................................................................12 3.4.2 Data Sources and Literature Review..........................................................12 3.4.2.1 Defining Gravel Quality and Fine Sediment Thresholds...............................................................................12 3.4.2.2 Fine Sediment in the Cedar River...........................................14 3.4.3 Methods......................................................................................................15 3.4.4 Results and Discussion..............................................................................16 3.5 Spawning History......................................................................................................17 3.5.1 Scope of Work...........................................................................................17 3.5.2 Data Sources..............................................................................................18 3.5.3 Methods......................................................................................................19 3.5.3.1 Defining Species of Interest....................................................19 3.5.4 Results and Discussion..............................................................................20 3.5.4.1 Historic Salmonid Escapement in the Cedar River ................20 USACE/CEDAR RIVER GRAVEL 04/ 15/02e i Draft Phase I Methods and Data Report Cedar River Grave[ Study 3.5.4.2 Redd Locations Identified in the Cedar River ........................22 3.5.4.3 Habitat Characteristics............................................................23 4 LITERATURE CITED.......................................................................................................25 APPENDIX A. CHANGES IN SEGMENT BREAK LOCATIONS DURING FIELD SAMPLING APPENDIX B. ADDITIONAL SOURCES OF CEDAR RIVER CROSS SECTION DATA APPENDIX C. FIELD DATA SUMMARIES FOR INDIVIDUAL SURVEY SITES APPENDIX D. U.S. FISH AND WILDLIFE SERVICE SUBSURFACE SEDIMENT SIZE DISTRIBUTIONS APPENDIX E. FINE SEDIMENT DATA SOURCES APPENDIX F. PHOTOGRAPHS FOR INDIVIDUAL SURVEY SITES APPENDIX G. MAPS FOR CEDAR RIVER GRAVEL STUDY PHASE I METHODS AND DATA REPORT USACE/CEDAR RIVER GRAVEL Draft Phase 1 Methods and Data Report 04115/02e 11 Cedar River Grave! Study • • List of Tables and Figures Table Page 1 Location and Characteristics of Study Segments Developed for the Cedar River Gravel Study.............................................................................................follows 6 2 Summary of Cross Sections Used in the Cedar River Gravel Study ..............................7 3 Sources of Surface Bed Material Size Distribution Data used for Cedar River Gravel Study...........................................................................................follows 10 4 Surface Bed Material Distributions and Selected Channel Characteristics Available for Phase 2, Cedar River Gravel Study............................................follows 10 5 Sources of Subsurface Bed Material Size Distribution Data and Fine Sediment Data Used for Cedar River Gravel Study.........................................follows 12 6 Subsurface Sediment Distributions Available for Analysis in Phase 2, Cedar River Gravel Study................................................................................follows 12 7 Relationship between Chinook Salmon and Steelhead Trout Embryo Survival and the Percentage of Fine Sediments Present in the Streambed...................13 8 NMFS Criteria for Fine Sediment Related Indicators of Watershed Condition and Function for Chinook Salmon Habitat..................................................14 9 Fine Sediment Observed in Bed Material Distributions during Other Studies of the Cedar River...............................................................................follows 14 10 Fine Sediment Sources and Indicators of Fine Sediment Accumulation on the Bed Surface of the Cedar River and its Tributaries ...................................follows 16 11 Spawning Data and Reports Reviewed for Use in Cedar River Gravel Study.............................................................................................................................18 12 Substrate, Velocity, and Depth of Flow Data Ranges from Studies Applicable to Cedar River Salmonids..............................................................follows 20 13 Stream Habitat Types for Observed Chinook Redds on the Cedar River.....................21 14 Sockeye Redds Observed in Close Proximity to Chinook Redds, Cedar River, 2000....................................................................................................................21 USACE/CEDAR RIVER GRAVEL Draft Phase I Methods and Data Report 04/15/02e iii Cedar River Gravel Study 15 Distribution of Total Area Spawned by Sockeye Salmon in Three Broad Segments of the Cedar River, 1973..............................................................................21 16 Maximum Number of Sockeye and Chinook Salmon Redds Observed in any Weekly Survey in the Lower Cedar River, 1998 to 2000......................................23 17 Cedar River 2001 Habitat Survey Data Summarized by Segment and River Mile..................................................................................................................follows 24 18 Habitat and Fish Observations at Cross Section Survey Sites on the Cedar River.................................................................................................................follows 24 Figure 1 d50 Sediment Size of Surface Bed Material Distributions Determined by Pebble Counts by River Mile on the Cedar River............................................follows 12 2 d50 Sediment Sizes of Subsurface and Corresponding Surface Bed Material Distributions by River Mile on the Cedar River................................follows 12 3 Percent Fine Sediment Distributions in the Cedar River Relative to Fine Sediment Threshold Criteria Established by the National Marine Fisheries Service..............................................................................................................follows 16 4 Historic Escapement of Chinook and Sockeye Salmon and Steelhead Trout in the Cedar River............................................................................................follows 20 5 Redd Counts for Chinook and Sockeye Salmon and Steelhead Trout in the CedarRiver......................................................................................................follows 22 6 Available Spawning Area as a Percentage of the Transect Area at Each SurveySite.......................................................................................................follows 24 7 Available Spawning Area as a Function of the d84, d50, and d16 Grain Sizes at Each Survey Site.................................................................................follows 24 USACE/CEDAR RIVER GRAVEL Draft Phase I Methods and Data Report 04/15/02e 1V Cedar River Gravel Study • Draft Phase I Methods and Data Report Cedar River Gravel Study 1 INTRODUCTION 1.1 Project Overview The team of Jones & Stokes, Perkins Geosciences, and Harper, Houf & Righellis is evaluating the current conditions of spawning gravel in the Cedar River from upstream of the Landsburg diversion dam to Lake Washington. Cooperating agencies include Seattle Public Utilities, the City of Renton, and King County Department of Natural Resources. The study will assess the quality and distribution of spawning gravel with respect to the hydraulic characteristics of the Cedar River. These sediment -hydraulic relationships will then be used to determine whether lack of gravel in certain reaches is caused by naturally occurring factors or human changes to channel morphology. The project is being implemented in two phases, with an optional third phase dependent on Phase 2 recommendations. Phase 1 activities include data collection and a literature review of current and historic research on the Cedar River. Data collection included surveys of additional cross sections and surface/subsurface bed material distributions; assessments of fine sediment influences on spawning success; and observations of redd distributions by gradient and confinement. This report documents methods involved in data collection and summarizes all data and information compiled for analysis under Phase 2. Phase 2 will evaluate these data and determine whether and where a "gravel problem" presently exists along the Cedar River. Phase 1 cross sections will be combined with existing cross sections from the King County and City of Renton HEC-RAS flood models to calculate the scour potential of various discharges at select cross sections which reflect a range of gradient, confinement, and management scenarios. Incipient motion particle size analyses at these cross sections will determine the flows necessary to initiate the downstream movement of gravel. Phase 2 will also include a quantitative evaluation of the current gravel supply and the impact of the Landsburg diversion on the size and quantity of sediments transported along the river. The study will determine whether spawning gravel supplies are limited as a result of channel modifications (levees, riparian management, flow regulation) and will identify potential restoration opportunities. Phase 3 will be scoped and initiated only if HEC-6 sediment modeling is required to fully implement Phase 2 recommendations. USACEICEDAR RIVER GRAVEL 1 Draft Phase I Methods and Data Report oatsio2e Cedar River Crave[ Study 1.2 Overview of Report Following this introduction, we describe our study approach, including identifying Phase 1 activities, documenting site selection criteria, and defining a spatial registration system along the river using river miles and study segments. The next section presents literature review results, data collection methods, and raw data summaries for each of the key information needs defined for Phase 1. These information areas, defined as tasks in the scope of work developed for the project (USACE 2001), are addressed in the following order: cross sections, surface gravel distributions, subsurface gravel distributions, fine sediment, and spawning history. Appendices include descriptions of data sources not used for Phase 2 analyses, data summary sheets for each survey site, photographs obtained at each site, and a 16-map set of the Cedar River showing study segments, sampling locations used in this study, and the known locations of hydraulic and sediment data collected by other investigators that are referenced in the text and data tables. 2 STUDY APPROACH 2.1 Phase 1 Work Activities A multi -agency meeting was held on June 21, 2001, prior to project commencement. Representatives included Seattle Public Utilities, City of Seattle, City of Renton, King County, Washington Department of Fish and Wildlife, U.S. Army Corps of Engineers, Perkins Geosciences, and Jones & Stokes. The objective of the meeting was to review and revise the scope of work. A list of potential sources of data applicable to the study was also developed, including published and unpublished reports, raw data, and various individuals and agencies. Notice to proceed with the project was received August 15, 2001. Phase 1 activities began with a review of literature and interviews with individuals having research experience on the Cedar River. The project team documented known data sources with potential value to the study, and developed a draft plan for data collection in areas where cross section and bed material data were lacking. The draft plan was evaluated during a 2-day float trip on August 16 and 17, 2001. The objective of the trip was to evaluate proposed sampling locations with regard to existing bed conditions and known, preferred spawning sites. The first day of the float trip covered the Cedar River from the Landsburg bridge to the Lion's Club and included Karl Burton (Seattle Public Utilities fish biologist); Terry Butler (King County geologist); Sue Perkins (Perkins Geosciences' geomorphologist); and Chris Soncarty and Mike Wolanek (Jones & Stokes' fish biologist and hydrologist, respectively). On the second day, Sue Perkins and Mike Wolanek covered the river from the Lion's Club to the I-405 bridge at Renton. The Cedar River Gravel Study Sampling Plan (Jones & Stokes 2001) was revised and submitted for review by the cooperating agencies on September 12, 2001. Because of time constraints involving chinook and sockeye spawning windows and low streamflows, field work commenced prior to submittal of the Sampling Plan for agency review. However, no comments were received from agency personnel that required changes in the Sampling Plan. USACE/CEDAR RIVER GRAVEL 2 Draft Phase ! Methods and Data Report 04/15/02c Cedar River Grave! Study Field work began August 27, and the last data were collected November 5, 2001. A review of the literature continued, and data from other sources were also summarized for use in Phase 2. Some previously unprocessed gravel samples from other investigators were analyzed in the laboratory and grain size distributions developed. Field data and data from the literature were then combined, analyzed, and summarized in preparation for Phase 2 data analyses. Cross section data were submitted to the team hydraulic engineer for HEC-RAS modeling under Phase 2. This report completes Phase 1 activities for this project. 2.2 Site Selection Prior to the August float trip, maps from previous HEC-RAS modeling efforts were obtained from King County and the City of Renton (these studies and associated maps are hereafter referred to as "flood study maps"). HEC-RAS data reports and GIS coverage of levee and revetment facilities managed by King County were also obtained. These materials, together with previous experience on the Cedar River, were used to identify preliminary segment characteristics (segments are described later in this section) and a number of potential cross sections for study. After field reconnaissance, approximately 50 cross sections downstream of the Landsburg bridge were selected for data collection. This included alternative cross sections to ensure that at least 30 were surveyed in the field. Cross sections with the following characteristics were more likely to be selected for study: ■ gradient and confinement characteristics typical of the segment description; ■ bed material distribution consistent with spawning gravel sizes typical of the segment; ■ generally uniform, rectangular channel (necessary for sediment transport calculations); ■ location at or near previous gravel studies for which data were available; and ■ location at or nearer to known preferential spawning areas as identified by Karl Burton, Seattle Public Utilities fisheries biologist. We attempted not to bias site selection toward "optimum" geomorphic and habitat characteristics that were atypical of the rest of the segment. Bed material distributions and other data collected as representative of these segments will be evaluated in Phase 2 in light of hydraulic characteristics at the specific cross sections where they were collected. Other sites of interest for additional pebble counts and subsurface gravel samples were identified during field reconnaissance and included in the Sampling Plan. These sites included gravel bars, bed features known as preferred salmonid spawning sites, and several tributaries. In addition to site selection downstream of Landsburg, the project hydraulic engineer identified on an aerial photograph five stations within about 1 mile upstream of Landsburg dam where cross sections would be surveyed. These cross section locations were selected to support development of a HEC-RAS model upstream of Landsburg, where no flood studies have USACE/CEDAR RIVER GRAVEL 3 Draft Phase 1 Methods and Data Report aul5/o2e Cedar River Gravel Study previously been completed. Phase 2 analyses upstream of Landsburg will be the same as for below Landsburg, except development of the HEC-RAS model above the dam requires the survey of new cross sections. 2.3 Referencing Data to Locations along the Cedar River This study utilizes two methods for recording and analyzing spatial data along the Cedar River river miles and study segments. 2.3.1 River Miles River miles (RM) reflect locations of features relative to the mouth of the Cedar River at Lake Washington (RM 0.0). The primary sources for these measurements are the 1:2400 scale flood study maps. Flood modeling occurred prior to the February 2001 landslide and channel avulsion at Elliott Park upstream of the Maplewood Golf Course (Segment 18 in this study). River miles were not modified to reflect the new channel location, partly because it is assumed that relatively low discharges since the landslide have resulted in negligible gravel transport from upstream segments to and through the segment. Gravel data (apart from increased fine sediment deposition) are assumed to have remained consistent with the hydraulic data modeled prior to the landslide. No additional data were collected in Segment 18 during this study. River miles upstream of the Landsburg dam at approximately RM 22.7 are estimated for this report from measurements taken from a July 1989 aerial photograph with scale of approximately 1:12672. River miles will be finalized in Phase 2 during HEC-RAS modeling of these upstream study segments. The river mile of each new cross section, pebble count, and field observation from this study, and the location of data from other studies, was determined by level surveys in the field or by measuring between established cross sections on the flood study maps. River miles assume flood study distances are accurate, and our measurements are rounded to two or three decimal places, where possible, to reflect the estimated precision of map and field measurements. 2.3.2 Study Segments The Cedar River was divided into study segments based on changes in gradient and confinement along the course of the river. The use of segments enables stratification of sediment data and other data according to these physical parameters. Habitat quality, frequency of fish use during spawning or other salmonid life stages, and other biotic characteristics were not considered during delineation of channel segments. Preliminary segment characteristics and segment breaks were identified in the office using the topographic flood study maps and data reports, GIS coverage of King County -managed levee and revetment facilities, and previous experience on the Cedar River. Segment breaks were then adjusted based on observations during field reconnaissance. A total of 22 segments, numbered consecutively from upstream to downstream, were presented in the Cedar River Gravel Study USACEICEDAR RIVER GRAVEL 4 Draft Phase 7 Methods and Data Report 64/I5/02e Cedar River Grave! Study Sampling Plan (Jones & Stokes 2001). Two minor changes to the segments identified in the Sampling Plan were made as described in Appendix A. Table 1 provides a summary of study segments, indicating their location by river mile and a description of their gradient and confinement. 3 FIELD DATA COLLECTION METHODS 3.1 Cross Sections 3.1.1 Scope of Work Requirements for this task identified in the scope of work are to ■ identify and query all relevant, existing cross section data from various agencies, and ■ survey up to 10 additional channel cross sections to support HEC-RAS modeling of the river, including 5 cross sections of the channel and floodplain upstream of the Landsburg dam. Selected sites encompass a range of confinement, gradient, and sediment supply situations. Survey data enable calculation of bankfull width, bankfull depth, and local energy gradient. 3.1.2 Data Sources Primary sources reviewed and used for this task include 1:2400 scale flood study maps of the King County and City of Renton HEC-RAS models; cross section field survey notes and/or benchmark documentation that support the models; and a bathymetric survey of the pool upstream of Landsburg dam provided by Seattle Public Utilities. Flood study cross sections are generally 500 to 700 feet apart on straight, uniform river reaches, and much closer on curved or complex reaches. Many of the cross sections are located at riffle crests, as is often the case with geomorphic work. However, because of the uniform, plane bed morphology characteristic of much of the river, cross sections are also common in runs, glides, and pool tail outs. Other studies with existing cross section data on the Cedar River include various scour and gravel monitoring studies. These studies provided little useful information because cross section data were never tabulated (as a result of an abbreviated study) (Peters 2001), were located in the depositional zone of Segments 21 and 22 (Jones & Stokes 2000a), or were primarily located at existing flood study cross sections (Golder Associates 2001 a). These studies are described in greater detail in Appendix B. 3.1.3 Methods Survey field notes, maps, and aerial photographs were used in the field to locate 30 flood study cross section locations downstream of Landsburg. On a number of sites the exact location of the cross section and/or local benchmark surveyed for the flood studies could not be determined. In USACEICEDAR RIVER GRAVEL 5 Draft Phase 1 Methods and Data Report 04/15/02e Cedar River Gravel Study these situations, the cross section location was estimated using the best available references (survey sketches, aerial photographs, flood study maps, survey field notes). Each cross section was visually evaluated to confirm that it met the characteristics described earlier under Section 2.2, "Site Selection." If a precise or estimated cross section had gradient, confinement, and gravel characteristics typical of the segment, and was generally uniform and rectangular, then it was considered suitable for data collection. If one or more of these characteristics appeared atypical of the segment, then three alternatives to cross section selection were considered: ■ conduct surveys at a flood study cross section location previously identified as an alternative in the sampling plan (Jones & Stokes 2001); ■ move the cross section to an adjacent "secondary" location; or ■ survey a new cross section at a new site (no flood study cross section). If an alternative cross section was located, it was evaluated against the same selection criteria. If the cross section met the criteria, it was selected to be surveyed without distinction from any other qualifying flood study cross section. At four cross sections, most channel characteristics were desirable, but bed material distributions contained a disproportionate range of spawning gravels relative to that typically observed in the segment. In these instances, a "secondary" cross section was created to bisect the bed material where spawning gravel was proportionate for the segment. Usually, the bed material at a cross section located at a riffle crest appeared to be coarser than the typical distribution for the segment, and the secondary cross section was located in the pool tail 30 to 50 feet upstream of the riffle crest. The project engineer later compared the four secondary cross sections to the adjacent flood study cross sections and found one that would probably result in significantly different hydraulic output from the HEC-RAS model. This cross section will be added to the existing King County HEC-RAS model during Phase 2 as a new cross section. The other "secondary" cross sections and their adjacent flood study cross sections are considered indistinguishable in terms of their hydraulic characteristics, and hereafter will be referred to simply as the flood study cross sections. In five instances, upon locating a cross section, several of the selection criteria could not be met. For example, the channel may have been visibly steeper, exhibited a local change in confinement or an extremely irregular form, or contained an atypical bed material distribution that could not be avoided through use of an adjacent "secondary" cross section as described above. A new cross section that was not previously surveyed for a flood study and that met most of the site selection criteria was identified and surveyed. These five new cross sections ranged from 115 to 270 feet from the nearest flood study cross section. The project engineer compared the new cross sections to their adjacent flood study cross sections and concluded they were appropriate for inclusion in a revision of the King County HEC-RAS model in Phase 2. With the one new cross section first located as a "secondary". site, a total of six new cross sections will be added to the King County HEC-RAS model downstream of Landsburg in Phase 2. USACE/CEDAR RIVER GRAVEL 6 Draft Phase 1 Methods and Data Report 04/15/02e Cedar River Grave! Study Table 1. Location and Characteristics of Study Segments Developed for the Cedar River Gravel Study Segment Number From RM To RM Segment Length miles Description Average 10-yr Flood Confinement Ratio' ft/ft Average Gradient`' % Gradient - Confinement Class` 1 23.665 23.180 0.485 Upstream of Landsburpool tbd' tbd Gc 2 23.180 22.71 0.470 Landsburg ool tbd tbd gc 3 122.71 22.15 0.560 Diversion dam to pipeline tbd tbd GC 4 22.15 21.000 1.150 Steep, tightly confined 0.96 0.70 GC 5 21.000 19.098 1.902 Confined w/ sed sources 2.29 0.62 GC 6 19.098 18.000 1.098 Tight bends w/ sed sources 3.20 0.73 GC 7 18.000 16.573 1.427 U er Dorre Don, variable confinement 4.03 0.48 GC 8 16.573 15.598 0.975 Lower Dorre Don, unconfined 7.80 0.64 Gc 9 15.598 14.750 0.848 Maple Valley confined, steeper 4.79 0.63 GC 10 14.750 14.064 0.686 Flatter, variable confinement; Peterson Cr. 11.84 0.46 gc 11 14.064 12.138 1.926 Bends, levees, variable confinement 8.09 0.47 gc 12 12.138 11.689 0.449 Lion's Club unconfined, flat 13.61 0.33 gc 13 11.689 11.012 0.677 Cedar Grove, floods despite levees 5.96 0.44 gC 14 111.012 10.226 0.786 Unconfined bends, 1990 avulsion, LWD jams 7.03 0.41 gc 15 10.226 9.625 0.601 Moderately confined, bedrock bends, flatter 2.15 0.34 gC 16 9.625 6.694 2.931 Jones Road, mostly confined 3.30 0.44 gC 17 6.694 5.210 1.484 Elliott Br., flatter, confined 4.36 0.37 gC 18 5.210 4.841 0.369 2001 Landslide 7.84° 0.51° Gc 19 14.841 4.576 0.265 1 Unconfined, side channels 6.75 tbd Gc 20 4.576 3.250 1.326 Maplewood, mostly confined 1.21 tbd gC 21 3.250 1 1.633 1.617 Confined, even flatter 1.16 0.32f ° C 22 1.633 0.0 1.633 Renton channel 1.07 0.25fd gC ' Calculated as the ratio of the wetted width of the 10-year flood elevation to the wetted width of the bankfull channel b Calculated as the average of the energy gradients of the 10-year flood event ' A four category classification based on gradient and confinement values relative to their mean. Gradient: steeper "G" values are > 0.47%, and flatter "g" values are <=0.47%. Confinement: more constrained "C" values are <=4.36, and more flood prone "c" values are >4.36. a To be determined (tbd) during phase 2 analyses Values represent conditions prior to February 2001 landslide f Low flow averages from Jones & Stokes 2000a measurements Upstream of Landsburg, five additional cross sections were located and surveyed in consultation with the project engineer to develop a HEC-RAS model for the one river mile upstream of the diversion dam operated by Seattle Public Utilities. This results in a total of 35 cross sections surveyed for the project, including 11 new cross sections. Regardless of whether the 35 cross sections were previous flood study cross sections (including secondary cross sections) or new cross sections surveyed specifically for this study, they were surveyed in order to document the current bed configuration, relate pebble count grain size distributions to bed forms, and serve as an interpretive aid during data analyses. Cross section descriptions are summarized in Table 2. Table 2. Summary of Cross Sections Used in the Cedar River Gravel Study River Mile Segment Number Site No. Source' Location Relative to a Flood Study Cross Section Datum` Benchmarkd 23.580 1 1 New this study At NAVD88 Landsbur 23.305 1 2 New this study At NAVD88 Landsbur 23.155 2 3 New this study At NAVD88 Landsbur 22.945 2 4 New this study At NAVD88 Landsbur 22.760 2 5 SPU At NAVD88 Landsbur 21.610 4 6 King 106 At Relative Local 21.261 4 7 King 101 At Relative Local 20.493 5 8 King 94B At NAVD88 94B 19.865 5 9 King 88 At NAVD88 88 18.546 6 10 King 74 At NAVD88 74 18.145 6 11 New this study 150 ft u/s18.117 NAVD88 69 17.592 7 12 King 65 At NAVD88 65 17.163 7 13 King 60 At Relative Local 16.159 8 14 King 50 At NAVD88 50 15.765 8 15 King 45 At NAVD88 45 14.906 9 16 King 36 At Relative Local 14.757 9 17 King 35 At NAVD88 35 14.575 10 18 King 33 At Relative Local 14.012 11 19 King 26 At Relative Local 13.208 11 20 New this study 115 ft u/s 13.186 NAVD88 19 12.666 11 21 King 13 At Relative Local 12.054 12 22 New this study 270 ft d/s 12.105 Relative Local 11.366 13 23 New this study 156 ft d/s 11.396 NAVD88 2 10.942 14 24 King 159 At NAVD88 159 10.865 14 25 King 158 At NAVD88 158 10.017 15 26 New this study 30 ft u/s 10.011 Relative Local 9.252 16 27 King 141 At Relative Local 8.193 16 28 King 131 At NAVD88 131 7.395 16 29 King 123 At Relative Local 6.216 17 130 1 King 111 At INAVD88 1111 USACEICEDAR RIVER GRAVEL .� Draft Phase 1 Methods and Data Report oalsro2e Cedar River Gravel Study Location Relative Segment Site to a Flood Study River Mile Number No. Source' Cross Section Datum` Benchmark 5.613 17 31 New this study 250 ft u/s 5.566 NAVD88 105 4.702 119 32 Renton BM At Relative Local 4.380 20 33 Renton BJ At Relative I Local 3.548 20 34 Renton AX At Relative Local 2.809 21 35 Renton AP At Relative Local ' King is King County flood study (with numeric cross-section survey ID); Renton is City of Renton flood study (with two -character alpha cross-section survey ID), SPU is Seattle Public Utilities bathymetric map b "At" is the actual or an adjacent secondary cross section location; u/s and d/s are upstream and downstream, respectively ` NAVD88 is the 1988 North American Vertical Datum; a "Relative" datum is a local benchmark d Benchmark describes any of the following: a local datum established for this study; a numeric or alphanumeric reference to a King County flood study cross-section (survey ID); or a previously established Landsburg benchmark (triangular afterbay for sites 1 through 5). Where an adjacent flood study benchmark or other benchmark could be located, each cross section was surveyed to an established datum, with elevations reported in feet NAVD88 (North American Vertical Datum 1988). Cross section elevations above Landsburg were established in NAVD88 by surveying to an established benchmark southwest of the screen house and afterbay. Where an existing benchmark could not be located, a relative benchmark was established near the cross section with an elevation of 100.00 feet. In the latter case, cross section elevations are reported with respect to this local benchmark. Any of the 11 new cross sections identified above with relative elevations can still be imported into the HEC-RAS model in Phase 2. The project engineer has already confirmed a reasonable fit of bank elevations at the new locations, and that modification of relative elevations to the NAVD88 datum in the model is appropriate. Cross section surveys downstream of Landsburg included only the channel and near -bank area (and did not include significant floodprone areas outside of the bankfull elevation). The project engineer will insert these new cross section data into averaged profiles of adjacent floodplains to estimate the actual channel and floodplain cross section during Phase 2. Above Landsburg, floodplains and sideslopes on each side of the channel were surveyed to an elevation generally greater than three times the estimated bankfull depth. A Topcon AT-7 level and tripod were used to survey elevations on a stadia rod in hundredths of feet. A tape stretched across the river at the cross section location identified channel and floodplain positions. Alternatively, when the level could be set up on the cross section, stadia were used to measure distance from the bank. Specific bed and bank positions commonly noted include pins (rebar) located on the right and/or left banks, left and right bankfull, left and right bank bottom, left and right edge of water, thalweg, in -channel slope breaks reflecting differences in bed material distributions, slope breaks adjacent to bankfull, and other floodplain features. Using these features, the following were calculated for each cross section: ■ bankfull width; USACE/CEDARRIVERGRAVEL Draft Phase I Methods and Data Report 04/15/02e 8 Cedar River Gravel Study ■ bankfull depth (the difference between the average of the two bankfull elevations and the average elevation of the right bank bottom, left bank bottom, and thalweg); ■ width/depth ratio (the quotient of bankfull width over bankfull depth); ■ bed width (the difference between right and left bank bottom); ■ wetted width (the difference between right and left edge of water); and ■ wetted depth (the average of all wetted verticals surveyed). After cross sections were surveyed, gradients were determined by measuring bed and water surface elevations of three longitudinal transects. The longitudinal transects were located at approximately one-fourth, one-half, and three-quarters of the wetted width at the cross section. Each transect was twice the bankf ill width of the cross section in length, bisected the cross section, and had elevations established at the upstream and downstream limits of the transect. Where changes in bed slope (profile) appeared significant along a longitudinal transect, the position and elevation of these breaks were also surveyed. The slope of each bed transect was reported as river left (25%), middle (50%), river right (75%), and the average of the three longitudinal transects. Water surface slope at the time of survey was calculated by averaging the hydraulic gradients of the three longitudinal transects. All cross section and other field data collected at each sample site are summarized and plotted for each cross section in Appendix C. 3.2 Surface Gravel 3.2.1 Scope of Work Requirements for this task identified in the scope of work include performing approximately 30 pebble counts of surface bed material in riffles and pool tailouts. Pebble counts are located near existing or new cross sections and focus on spawnable gravels where feasible. Sample sites encompass a range of confinement, gradient, and sediment supply situations. Additional supporting data include bankfull width, bankfull depth, energy gradient, habitat type, and potential spawnable gravel (sketch). 3.2.2 Data Sources In addition to data collected in the field during this study, surface bed material distributions were obtained for the Cedar River from several other sources. All data sources considered for use in this study are identified in Table 3. USAC&CEDAR RIVER GRAVEL 9 Draft Phase I Methods and Data Report oat sioze Cedar River Grave! Study 3.2.3 Methods Study cross sections were selected as described earlier under Section 2.2, "Site Selection" and Section 3.1, "Cross Sections." Once the cross section was located in the field, a survey tape measuring tenths of feet was strung across the river at the cross section. The bed between the left bank bottom and right bank bottom was visually assessed to determine whether bed material was uniformly distributed across the entire cross section, or patterns existed that reflect bed features such as margins, bars, benches, berms, thalweg, and excessive depth for sampling. Appropriate breaks for identifying up to four subsample areas along the cross section were identified by tape distance and discussed with all surveyors. Pebble counts were then conducted using methods consistent with Wolman (1954), Kondolf (1997, 2000), and Bunte and Abt (2001). Specific procedures follow. Where bed material was uniformly distributed, the entire bed from bank bottom to bank bottom was surveyed in two or more transects walked parallel to the cross section. A minimum of 100 particles was tallied on a field form identified as "Pebble Count A." Each individual sample transect at a site reflects the complete bed width (no stopping at 100 rocks). The maximum mobile diameter was measured after specifically searching for the largest mobile particle in the sampled area. Particles were considered frequently mobile if they were rounded or subangular, generally bright, had minimal aquatic vegetation attached, and were at or partially buried below the bed surface. Where bed material was not uniformly distributed, one pebble count (as above) was performed over the area at the cross section with the best spawning gravel. Other areas were also sampled by pebble count if the bed material distribution represented a significant portion of the survey area. The maximum mobile diameter was measured for each area receiving a pebble count. Data were recorded on a field form as "Pebble Count B" or "Pebble Count C." Areas between bank bottoms that were not surveyed by pebble counts were characterized by visually estimating either the size class or actual grain sizes for these statistics: maximum, 84th percentile (d84), median (00), 16th percentile (dl6), and minimum. At some sites the maximum mobile diameter was also estimated. Although not a pebble count, these data were recorded on a field form as "Pebble Count B" or "Pebble Count C." Pebble counts were also performed at select sites of interest along the river, including tributary streams, gravel bars, benches known to be preferred spawning sites, and the surface or armor layer over subsurface sample sites. Maximum, maximum mobile, d84, d50, d16, and minimum statistics were calculated for pebble counts and are summarized and plotted for all pebble counts and visual estimates on all sample sites in Appendix C. Data for characterizations of "primary" gravel at each sample site (i.e., Pebble Count A) are summarized in Table 4. The values of the d84, d50, and d16 sizes were determined graphically by extending verticals from the plotted distribution to log -scale grain sizes on the abscissa (x-axis). In addition to sediment data, bankfull width, bankfull depth, water surface slope, and bed slope were surveyed as described under Section 3.1, "Cross Sections." Other channel characteristics USACEICEDAR RIVER GRAVEL 1 O Draft Phase I Methods and Data Report 04/I5/02e Cedar River Gravel Study Table 3. Sources of Surface Bed Material Size Distribution Data used for Cedar River Gravel Study Source Date/Purpose of Study Location Method / Sample Size Data Reported This study 2001; Evaluate bed material size 39 locations along Pebble counts partitioned by bed Complete graphic & tabular grain distribution to hydraulic characteristics mainstem between RM feature; distributions across 18 size distributions for each site; at cross sections 2.3 and 23.6; four size classes; some visual summaries of d16, d50, d84, tributary streams estimates of size distributions maximum mobile size King County 1992; Investigate sediment 20 locations along entire Pebble counts d16, d50, d84 at each sample site (1993) characteristics for Conditions Report river; one tributary channel Jones & Stokes 1998, 1999, 2000; Monitor scour and 10 locations between Pebble counts of entire bed d16, d50, d84 at each site in (2000a) bed material changes upstream of RM 1.26 and 2.04, width; distributions across 10 size 2000; annual changes displayed dredging Segments 21 and 22 classes graphically USFWS (2001) 1999, 2000; Relate cross-section and 7 study sites' between Pebble count; distributions across d16, d50, d84 at each sample site gravel characteristics to the depth of RM —4.5 and 12.05 23 size classes (14 classes < 256 in 2000 scour indicated by scour chains mm, not including 5 classes <1 mm Inter-Fluve 2000; Sediment transport through 2 sites on bar Pebble count; distributions across Tabular grain size distribution at (2000) Landsburg dam immediately u/s of 14 size classes each sample site Landsburg dam; —RM 22.7, Segment 2 Golder (2001 a) 2001; Monitor gravel augmentation 4 sites d/s of gravel Pebble count; distributions across Tabular grain size distribution at (mitigation) d/s of Landsburg bridge berm, between RM 16 size classes each sample site 21.75 and 22.0 in Segment 4 e 2nd Cedar River Trail crossing south of Maple Valley, d/s of the SR 169 and Cedar River Trail crossings north of Maple Valley, Lion's Club, Dirt Plant, Cedar Rapids, Buck's Curve, and Elliott Park. Table 4. Surface Bed Material Distributions and Selected Channel Characteristics Available for Phase 2, Cedar River Gravel Study Segment River Mile Source Feature Method Bed Material Particle Size mm Bankfull Width feet Bankfull Depth feet Water Surface Slope feet/foot Average Bed Slope feet/foot Maximum Mobile Maximum d84 d50 d16 Minimum 1 23.580 This study XS, no margin PC nd 113 54 32 12 0.1 137.7 2.92 0.0015 -0.0027 1 23.58 This study RB margin 11' of XS Visual nd 25 4 2 0.1 0.1 1 23.43 This study Lateral bar PC 96 41 24 10 0.1 1 23.305 This study XS, no margin PC 186 161 81 40 10.5 2 112.0 3.80 0.0037 -0.0012 1 23.305 This study Inner berm of thalwe (18') Visual nd 762 500 381 190 4 1 23.305 This study LB margin 24' of XS Visual nd 449 321 3 1.5 0.1 1 23.21 This study Lateral bar 1/4 length from u/s tip) PC 153 161 91 62 35 12 1 23.21 This study Lateral bar 1/3 length from d/s tip) PC 210 113 70 50 33 12 1 23.20 Inter-Fluve 2000 Riffle upstream of impoundment PC 192 75 53 11 0.1 2 23.155 This study XS, at upper limit of Landsburg Pool, no margin Visual 210 81 29 6 1.5 0.1 83.0 4.02 nd nd 2 23.155 This study RB margin & thalwe 23' Visual nd 1537 225 41 5.5 0.1 2 22.945 This study XS, in Landsburg reservoir, complete Visual nd 769 nd nd nd 0.1 105.0 6.95 nd nd 2 22.78 Inter-Fluve 2000 Gravel bar in impoundment PC 192 68 40 22 0.1 2 22.760 This study XS, in Landsburg reservoir, complete Visual nd nd nd nd nd nd nd nd nd nd 2 22.74 Inter-Fluve 2000 Gravel bar in impoundment PC 192 68 40 22 0.1 4 21.97 Golder 2001 a XS, com fete PC 450 59 18 4 21.95 Golder 2001a) XS, complete PC 400 70 22 4 21.90 Golder 2001a XS, complete PC 440 190 73 4 21.75 Golder 2001a XS, PC 410 105 17 4 21.610 This study XS, complete PC nd 769 320 61 4.5 0.1 87.9 4.02 0.0031 0.0046 4 21.261 This study XS, complete PC nd 449 160 41 10 0.1 92.1 3.83 0.0023 -0.0041 5 20.80 King Co 1993 Point or lateral? bar PC 193.2 86.4 26.7 5 20.493 This study XS, complete PC nd 449 85 36 9 0.1 96.9 3.49 0.0035 0.0032 Tributary 20.432 King Co 1993 Walsh Lake Diversion Ditch PC 185.7 88.2 24.9 5 20.40 King Co 1993 Point or lateral?) bar PC 169.4 141.4 24.2 5 19.865 This study XS, complete PC nd 769 300 160 42 6 103.6 2.24 0.0100 0.104 6 18.70 King Co 1993 Point or lateral? bar PC 203.4 94.8 41.2 6 18.546 This study XS, complete PC 260 449 150 84 45 4 104.2 3.10 0.0077 0.0117 Tributary 18.517 This study Rock Creek PC 256 155 88 50 27 0.1 6 18.145 This study XS, no margin or thalweg PC 125 113 57 37 19 8 84.3 4.16 0.0007 0.0022 6 18.145 This study Thalweg of XS (22') Visual nd 256 161 113 81 29 6 18.145 This study RB margin of XS (11') Visual nd 120 41 29 21 0.1 7 17.592 This study XS, complete PC 270 225 120 55 20 0.1 72.2 3.32 0.0017 0.0015 7 17.30 King Co 1993 Point or lateral? bar PC 107.8 49.6 16.8 7 17.163 This study XS, complete PC 310 225 120 81 38 6 67.0 3.73 0.0012 -0.0022 8 16.159 This study XS, complete PC 321 321 100 52 28 2 66.3 3.75 0.0016 0.0071 Side channel 15.869 This study Dorre Don Side Channel PC 210 225 61 31 16 0.1 8 15.765 This study XS, complete PC 258 225 113 57 28.5 0.1 117.0 3.36 0.0090 0.0036 8 15.70 Kin Co(1993) Point or lateral?) bar PC 139.7 75.5 24 9 14.906 This study XS, complete PC 450 321 160 61 32 0.1 99.1 3.11 0.0067 0.0047 9 14.757 This study XS, complete I PC 1390 1321 1 113 160 131 i 1.5 92.4 12.52 0.0022 10.0019 Segment River Mile Source Feature Method Bed Material Particle Size mm Bankfull Width feet Bankfull Depth feet Water Surface Slope feet/foot Average Bed Slope feet/foot Maximum Mobile Maximum d84 d50 d16 Minimum 9 14.757 This study Low bench PC 160 161 60 38 17 0.1 92.4 2.52 0.0022 0.0019 10 14.575 This study XS, complete PC 320 321 101 36 14 0.1 89.6 2.92 0.0029 0.0015 Tributary 14.447 This study Peterson Creek PC nd 225 170 80 31 0.1 11 14.012 This study XS, complete PC 315 225 110 55 13 0.1 115.4 3.22 0.0036 -0.0035 Tributary 13.408 This study Taylor Creek nd nd nd nd nd nd nd 11 13.40 King Co 1993 Point or lateral?) bar PC 140.4 176.8 27.6 11 13.208 This study XS, no thalweg PC 205 161 67 43 19 0.1 96.3 3.42 0.0094 0.0057 11 13.208 This study Thalweg at RB 19' Visual nd 161 81 70 29 21 11 12.666 This study XS, no thalweg PC 205 225 110 79 49 21 83.8 3.05 0.0056 0.0141 11 12.666 This study Thalweg of XS 27' Visual nd 250 161 110 41 29 Tributary 12.605 This study Unnamed Creek PC nd 161 65 21 0.1 0.1 12 12.054 This study XS, no margin PC 130 161 57 31 14 0.1 81.5 3.78 0.0003 -0.0018 12 12.054 This study Thalweg of XS 14' Visual nd 113 81 57 21 1 12 12.054 This study LB margin 5' of XS Visual nd 4 4 2 0.5 0.5 12 12.054 This study RB margin 13' of XS Visual nd 16 15 4 0.5 0.5 12 12.05 USFWS 2001 Lions -Upper -Control (complete cross section PC 512 160 62 9 0.1 12 12.05 USFWS 2001 Lions -Upper -Tag inner berm at scour chains PC 1024 75 39 12 0.1 12 12.00 USFWS 2001 Lions -Lower -Tag inner berm at scour chains PC 256 88 38 12 0.1 12 12.00 USFWS 2001 Lions -Lower -Control (complete cross section PC 512 160 68 9 0.1 12 11.70 King Co 1993 Point or lateral? bar PC 155.7 79.5 32.1 13 11.366 This study XS, complete PC 260 161 65 39 18 0.1 100.8 1.80 0.0021 -0.0042 13 11.30 King Co 1993) Point or lateral? bar PC 86 57.6 47.4 14 10.942 This study XS, no thalweg PC 167 161 75 30 10 0.1 70.0 3.81 0.0016 -0.0025 14 10.942 This study Thalweg at LB 15' Visual nd 321 240 120 100 1.5 14 10.942 This study Low lateral bench PC 138 81 45 22 9 0.1 70.0 3.81 0.0016 -0.0025 14 10.865 This study XS, complete PC 210 161 91 55 24 0.1 92.2 3.92 0.0012 -0.0029 14 10.366 This study Point bar PC 240 240 94 40 24 0.1 15 10.017 This study XS, complete PC 260 321 150 90 32 0.1 100.0 2.02 0.0031 0.0070 15 10.017 This study Small side channel Visual nd 260 80 35 5.5 0.5 16 9.30 King Co 1993 Point or lateral? bar PC 129.4 56.3 24 16 9.252 This study XS, w/ thalwe (50') PC 250 225 120 54 5 0.1 115.7 2.37 0.0028 -0.0011 16 9.252 This study XS, top of berm (18') PC 160 161 59 41 18 0.1 115.7 2.37 0.0028 -0.0011 16 9.252 This study LB margin of XS 38' Visual 172 172 100 40 30 0.5 16 8.193 This study XS, no thalweg PC 260 321 110 39 3 0.1 75.0 3.73 0.0011 -0.0066 16 8.193 This study Thalweg of XS near LB 25' Visual 280 280 240 100 15 0.5 16 8.19 USFWS 2001 Dirt Plant -Control (complete cross section) PC 3000 145 57 6 0.1 16 8.19 USFWS 2001 Dirt Plant -Tag (inner berm at scour chains) PC 2048 160 65 22 0.1 16 7.75 USFWS 2001 Cedar Ra ids -Control (complete cross section PC 1024 175 72 18 0.1 16 7.75 USFWS 2001 Cedar Ra ids -Tag (inner berm at scour chains) PC 256 140 57 23 0.1 16 7.50 King Co 1993 Point or lateral? bar PC 180.7 114.8 50.5 16 7.395 This study XS, no thalweg PC 280 321 80 40 18 0.1 95.9 3.56 0.0017 0.0017 16 7.395 This study Thalweg of XS near LB 26' Visual 240 240 16 57 41 20 16 6.90 King Co 1993 Point or lateral?) bar PC 155.4 62.6 25.9 17 6.311 1 This study 500 ft u/s of 6.216 in segment PC nd 1161 70 141 19 1.5 _ Segment River Mile Source Feature Method Bed Material Particle Size mm Bankfull Width feet Bankfull Depth feet Water Surface Slope feet/foot Average Bed Slope feet/foot Maximum Mobile Maximum d84 d50 d16 Minimum 17 6.216 This study XS, no thalweg PC 360 321 150 70 24 0.1 105.8 2.40 0.0075 0.0094 17 6.216 This study Thalweg of XS near LB 32') Visual nd 321 161 81 29 0.1 17 6.00 King Co 1993) Point or lateral?) bar PC 114.3 72.8 31.4 17 5.82 USFWS (2001) Bucks -Upper -Tag (riffle d/s of scour chains) PC 2048 70 34 10 0.1 17 5.82 USFWS 2001) Bucks -Upper -Control (complete cross section) PC 1024 75 35 10 0.1 17 5.75 USFWS 2001) Bucks -Lower -Tag (riffle d/s of scour chains) PC 512 140 62 8 0.1 17 5.75 USFWS (2001) Bucks -Lower -Control (complete cross section) PC 362 72 36 11 0.1 17 5.613 This study XS, complete PC 190 161 102 42 22 5.5 98.9 2.05 0.0021 0.0013 18 4.90 King Co 1993) Point or lateral?) bar PC 122.5 71.8 36.5 19 4.702 This study XS, no margin PC 220 225 88 35 4 0.1 143.7 2.32 0.0065 0.0045 19 4.702 This study RB margin of XS (13') Visual nd 2 1.5 1 0.1 0.1 19 4.70 USFWS 2001 Elliott -Upper -Tag riffle d/s of scour chains) PC 180 84 49 17 2 19 4.70 USFWS (2001) Elliott -Upper -Control (complete cross section) PC 256 105 55 19 0.1 19 4.63 USFWS (2001) Elliott -Lower -Control (complete cross section) PC 512 88 48 14 0.1 19 4.63 USFWS 2001) Elliott -Lower -Tag riffle d/s of scour chains) PC 256 82 48 14 0.1 20 4.60 King Co (1993) Point or lateral?) bar PC 100.4 46.2 20.4 20 4.380 This study XS, no margin PC 200 225 110 60 7 0.1 180.8 1.59 0.0084 0.0053 20 4.38 This study Top berm nr RB margin (24') Visual 115 115 100 70 30 0.1 20 4.38 This study RB margin of XS 14' Visual nd 1537 29 2 1 0.1 20 4.00 King Co 1993) Point (or lateral?) bar PC 120.5 53.3 23.9 20 3.548 This study XS, no margin PC 150 161 57 29 4 0.1 115.0 2.40 0.0017 -0.0021 20 3.548 This study RB margin of XS (16') Visual nd 60 30 20 1.5 0.1 21 2.30 King Co 1993 Point or lateral?) bar PC 85.4 34.2 8.9 21 2.809 This study XS, complete PC 180 113 81 44 24 0.1 87.5 1 3.58 0.0024 0.0028 21 2.040 Jones & Stokes (2000a) XS, in run, complete PC 256 79 40 11 0.1 21 1.940 Jones & Stokes 2000a) XS, in riffle, complete PC 256 100 53 21 0.1 21 1.850 Jones & Stokes 2000a XS, in run, complete PC 256 88 40 12 0.1 21 1.750 Jones & Stokes (2000a) XS, in run, complete PC 256 83 38 17 0.1 22 1.620 Jones & Stokes (2000a) XS, in glide/pool, complete PC 128 46 16 0.5 0.1 22 1.530 Jones & Stokes 2000a) XS, in run, complete PC 512 90 25 11 0.1 22 1.440 Jones & Stokes 2000a) XS, in run, complete PC 256 82 31 6.5 0.1 22 1.340 Jones & Stokes (2000a) XS, in run, complete PC 256 70 31 4.5 0.1 22 1.300 Jones & Stokes (2000a) XS, in riffle, complete PC 128 65 28 9.5 0.1 22 1.260 Jones & Stokes (2000a) XS, in run, complete PC 256 90 40 17 0.1 22 1.200 King Co (1993) Point (or lateral?) bar PC 33.1 16.6 6.2 22 1.000 King Co (1993) Point (or lateral?) bar PC 27.6 12.7 1.4 22 0.55 King Co (1993) Point or lateral?) bar PC 32.5 18.7 4.4 22 0.27 1 King Co (1993) Point (or lateral?) bar PC 129.7 17.8 8.3 xs = cross section pc = pebble count nd = no data bulk = bulk sample includes surface and subsurface material were described at each site for the area bisected by the cross section that is the wetted width by two times the bankfull width long. These include habitat type, available spawning area (ASA), gravel bars, a sketch of the site, and others. These data are included in the field data summaries for each site in Appendix C. ASA is discussed in greater detail under Section 3.5, "Spawning History." Surface bed material distributions from other studies were summarized by noting, where possible, their maximum, d84, d50, and d16, and minimum size classes. These data are included in Table 4 and d50 data determined from pebble counts are displayed by river mile in Figure 1. 3.3 Subsurface Gravel 3.3.1 Scope of Work Requirements for this task identified in the scope of work include collection of up to four subsurface bed material samples to determine bedload size distribution using a volumetric approach. Samples are collected at sites that supplement existing subsurface data collected in 1992 by King County. In addition, similar methods are used to ensure data are comparable. These subsurface samples are not intended to quantify fine sediment intrusion into spawning gravel. 3.3.2 Data Sources In addition to data collected in the field during this study, subsurface bed material distributions were obtained for the Cedar River from several other sources. All data sources considered for use in this study are identified in Table 5. 3.3.3 Methods For this study, subsurface sampling methods followed those of Booth (2000). This volumetric approach involved wet sieving of samples in the field and is essentially the same method employed by King County in 1992. Sue Perkins, of Perkins Geosciences, was involved in both this study and the King County study. Two subsurface samples were collected on exposed, recent gravel bars at about RM 23.21 (Segment 1; upstream of the Landsburg diversion dam) and RM 10.366 (Segment 14). At each site, a pebble count inventoried the bed material distribution of the surface in an area about 2.5 m by 2.5 m, above the sample volume. The armor layer (about 2 grain diameters thick) was removed and discarded from about 1.5 mZ, exposing an area 1 m by 1 m for subsurface sample collection. An 80-liter sample was collected and a 20-liter subsample sieved into 11 size classes: 256, 128, 64, 53, 31.5, 16, 8, 4, 2, 1, and <1 mm. Each of these fractions was measured volumetrically through water displacement. USACE/CEDAR RIVER GRAVEL 1 1 Draft Phase I Methods and Data Report 00/15/02e Cedar River Grave[ Study The grain size distributions of six subsurface samples of varying volumes collected by the U.S. Fish and Wildlife Service (USFWS) and Inter-Fluve were determined similarly in the lab. The d84, d50, and d16 diameters of each subsurface sample are summarized with their corresponding surface sediment sizes in Table 6 and d50 data are shown in Figure 2. 3.4 Fine Sediment 3.4.1 Scope of Work The scope of work for this task requires a literature review to document existing fine sediment data, including sources and percent fines in the bed material. These data are to be compared to published data demonstrating how percent fines in spawning gravels may impact salmonid redds, egg survival, and fry emergence. McNeil core sampling for fine sediment characterization is not within the scope but could be conducted if the literature and field observations suggest fine sediment could be limiting spawning success. 3.4.2 Data Sources and Literature Review We reviewed the literature to define a scientific context for fine sediment and to document the observations of fine sediment in the Cedar River by other investigators. Additional data were recorded in the field as part of this study and are discussed in detail under Section 3.4.3, "Methods." 3.4.2.1 Defining Gravel Quality and Fine Sediment Thresholds Fine sediment deposition in critical aquatic habitats, including salmonid spawning gravel, is a well known issue of substrate quality (Bauer and Ralph 2001). A body of literature supports the assumption that fine sediments are detrimental to salmonid populations through habitat alteration and direct effects on survival of eggs and embryos (Everest et al. 1987, Havis et al. 1993, Bjornn and Reiser 1991). Fine sediments smaller than about 1 mm have been shown to affect intragravel dissolved oxygen concentrations and survival of eggs and alevins. Sediments smaller than about 4 to 6.4 mm may infiltrate salmon redds, thereby reducing oxygen uptake and alevin emergence. Bjornn and Reiser (1991) demonstrate reductions in embryo survival with increasing fine sediment less than 6.35 mm in size (Table 7). Establishing threshold criteria to define the quantity of fine sediment that detrimentally affects salmonids has been difficult. No single grain size parameter can be expected to universally predict embryo survival to emergence, even for a single species (Lisle and Eads 1991). Although bed material size distributions are quantitative and appear inclusive of all sediments, they are often incomplete with respect to fisheries applications. The use of bed material distributions should consider, for example, spatial variation across bed forms, temporal variation in fine sediment distributions through salmonid life cycles, and uncertainty in the measurement of background levels of fine sediment. Kondolf (2000) agrees that assessing salmonid spawning gravel quality by using a single statistic drawn from bed material distributions may be USACEICEDAR RIVER GRAVEL 12 Draft Phase I Methods and Data Report W15/02e Cedar River Gravel Study 170 160 150 140 130 120 110 E 100 N in 90 a� U 80 m °- 70 0 60 50 40 30 20 10 0 Jt T. J AA L4 rn 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 River Mile -+- Mainstem ♦ Tributaries Figure 1. d50 Sediment Size of Surface Bed Material Distributions Determined by Pebble Counts by River Mile on the Cedar River Table 5. Sources of Subsurface Bed Material Size Distribution Data and Fine Sediment Data Used for Cedar River Gravel Study Source Date/Purpose of Study Location Method / Sample Size Data Reported This study 2001; Evaluate bed material size 2 locations: on point bar in Segment 1 Volumetric; distributions across 11 Summaries of distribution to hydraulic at RM 10.366; on lateral bar in size classes; 80 L sample size d16, d50, d84 characteristics at cross sections Segment 14 at RM 23.21 sizes Kiiig County (1993) 1992; Investigate sediment 20 gravel bar locations along entire Volumetric for 9 size classes between d16, d50, d84 at characteristics for Conditions Report river; one tributary channel <1 and 256 mm; 80 L sample size each sample site USFWS (2001) 1999, 2000; Relate cross-section and 2 underwater bed samples (near shore, Volumetric/ gravimetric; selected d16, d50, d84 at gravel characteristics to the depth of off shore) each at 10 sites near: Lion's samples collected but not processed each sample scour indicated by scour chains Club, Dirt Plant, Cedar Rapids, were analyzed as part of this study; site Buck's Curve, and Elliott Park sample sizes ranged from 1 to 4 ft3 Inter-Fluve (2000) 2000; Sediment transport through 3 samples from bar immediately u/s of Volumetric; samples collected but not d16, d50, d84 at Landsburg dam Landsburg dam; —RM 22.7, processed were analyzed as part of each sample Segment 2 this study; sample sizes each less than site 1 ft3 CES (1995) 1994; Sediment transport analyses 2 underwater bed samples at each of Gravimetric analyses of 0.5 ft3 bulk Tabular and 37 sites in 4 general areas along the samples' for 20 standard size classes graphical grain river; depth ranges are 0 to 5 inches (15 classes < 4 in.) size distribution and 5 to 9 inches below the surface Stober and Graybill 1973; Determine depths and velocities 11 underwater bed locations between Volumetric, on bulk samplesb, for Graphical grain (1974)° preferred by spawning sockeye; RM 1.5 and 19.8 using McNeil core 9 size classes between 0.105 and 26.9 size distribution understand effects of discharge during sampler mm; assume fairly small sample low flows volume SAIC (1997)° 1997; Characterize sediments and 5 composite bed samples near mouth, Gravimetric on bulk samples b; 4 size Tabular grain pollutants in material to be dredged from RM 0.0 to 1.1; Segment 22 classes, largest is 2 mm; small sample size distribution size for 5 composite samples Golder (2001 a)* 2001; Monitor gravel augmentation Grain size distribution of dredged Gravimetric analyses of three Tabular and (mitigation) d/s of Landsburg bridge materials from RM 0.0 to 1.25 placed composite bulk samplesb using graphical grain d/s of RM 22.0 13 standard sieve sizes size distribution e These studies primarily support an assessment of fine sediment (and not sediment transport analyses) because sampling, analysis, and/or reporting practices excluded the coarse fraction of bed sediments. See discussion under "Fine Sediment." b Bulk samples collected in these studies are known or assumed to include surface armor as well as subsurface bed material, except that the CES (1995) data collected at 5 to 9 inches below the surface would not contain any surface armor material. Table 6. Subsurface Sediment Distributions Available for Analysis in Phase 2, Cedar River Gravel Study Segment River Mile Source Feature' Subsurface Particle Size mm Surface Particle Size mm b Sample Size (% of largest clast d84 d50 d16 d84 d50 d16 1 23.21 This study Point Bar 105 50 14 91 62 35 1 1.9% 2 22.790 Inter-Fluve 2000 Bar 425 ft u/s of dam 45 38 18 68 40 22 2 22.738 Inter-Fluve 2000 Bar 150 ft u/s of dam 90 32 7 68 40 22 2 22.716 Inter-Fluve 2000 Bar 30 ft u/s of dam 84 65 9 5 20.46 CES 1995 Avg of 4 samples on XS in glide 95 27 3 81 33 7 5 20.45 CES (1995) Avg of 2 samples on XS near RB in glide tailout 99 39 5 200 120 70 5 20.4 King Co 1993 Point or lateral? bar 81.5 68.6 4.2 169.4 141.4 24.2 12.9% 6 18.7 King Co 1993 Point or lateral? bar 68.3 43.6 8.2 203.4 94.8 41.2 4.8% 7 17.3 King Co 1993 Point or lateral? bar 68.7 41.6 3.4 107.8 49.6 16.8 7.0% 7 17.3 CES (1995) Avg of 4 samples on XS in glide(?) u/s of medial bar 120 20 3 60 33 14 7 17.25 CES (1995) Avg of 2 samples on XS in fast cobble run in larger of 2 channels around medial bar 45 13 2 57 26 6 8 15.7 King Co 1993 Point or lateral? bar 93.5 70.6 5.4 139.7 75.5 24 5.0% 11 13.4 King Co 1993 Point or lateral? bar 83.3 67 5.4 140.4 76.8 27.6 4.3% 12 11.7 King Co 1993 Point or lateral? bar 56.2 160.3 5 155.7 79.5 32.1 16.2% 13 11.06 CES (1995) Avg of 2 samples on XS at top of straight glide 110 52 7 150 100 66 13 11.04 CES (1995) Avg of 2 samples on XS near RB in mid -glide 80 23 2 110 82 30 13 11.02 CES (1995) Avg of 4 samples on XS in glide tailout 61 22 3 88 45 15 Segment River Mile Source Feature' Subsurface Particle Size mm Surface Particle Size mm b Sample Size (% of largest clast d84 d50 d16 d84 d50 d16 13 11.01 CES (1995) Avg of 2 samples on LP near RB in straight glide tailout 49 13 1 61 35 13 14 10.366 This study Large Point Bar 160 47 8 94 40 24 2.1% 16 19.3 King Co 1993 Point or lateral? bar 69.1 72 11.4 129.4 56.3 24 3.7% 16 7.5 King Co 1993 Point or lateral? bar 96.2 73 6.2 180.7 114.8 50.5 6.2% 16 6.9 King Co 1993 Point or lateral? bar 90.2 53.6 6.8 155.4 62.6 25.9 7.3% 17 6 King Co 1993 Point or lateral? bar 61.7 23 2.4 114.3 72.8 31.4 6.2% 18 5.06 CES (1995) Avg of 2 samples on XS in deep Tide 130 124 3 120 55 26 18 5.04 CES (1995) Avg of 2 samples on XS in glide tailout 65 19 2 120 85 36 18 5.02 CES (1995) Avg of 3 samples on XS in mid- riffle 85 20 2 99 55 21 18 4.97 CES (1995) Avg of 4 samples on LP near inside of curve in glide 60 19 2 77 41 16 18 4.96 CES (1995) Avg of 4 samples on XS in glide tailout 85 36 6 100 48 19 20 4.6 King Co 1993 Point or lateral? bar 45.8 13.6 1.4 100.4 46.2 20.4 3.4% 21 12.3 King Co 1993 Point or lateral? bar 37 1 16.2 1.2 85.4 34.2 8.9 2.6% 22 1.2 King Co 1993 Point or lateral? bar 17.7 9.2 1.4 33.1 16.6 6.2 1.3% 22 1 King Co 1993 Point or lateral? bar 18.1 9.2 1.4 27.6 12.7 1.4 1.2% 22 0.55 King Co 1993 Point or lateral? bar 16 9.4 0.8 32.5 18.7 4.4 1.2% 22 0.27 King Co 1993 Point or lateral? bar 9.8 7.2 1.4 129.7 1 17.8 18.3 1 1.4% Sites below have bulk surface and subsurface sam les collected by USFWS that are awaiting processing' 12 12.05 USFWS 2001 Lions Upper -Off -Surface 75 39 12 12 12.05 USFWS 2001 Lions Upper -Off -Subsurface 75 39 12 12 12.05 USFWS 2001 Lions Upper -Near -Surface 75 39 12 12 12.05 USFWS 2001 Lions Upper -Near -Subsurface 75 39 12 Segment I River Mile Source Feature' Subsurface Particle Size mm Surface Particle Size mm b Sample Size (% of largest clast d84 d50 d16 d84 d50 d16 12 12.00 USFWS 2001 Lions Lower -Off -Surface" 88 38 12 12 12.00 USFWS 2001 Lions Lower -Off -Subsurface` 88 38 12 12 12.00 USFWS 2001 Lions Lower -Near -Surface` 88 38 12 12 12.00 USFWS 2001 Lions Lower -Near -Subsurface' 88 38 12 16 8.193 USFWS 2001 Dirt Plant -Off -Surface 160 65 22 16 8.193 USFWS 2001 Dirt Plant -Off -Subsurface 160 65 22 16 8.193 USFWS 2001 Dirt Plant -Near -Surface 160 65 22 16 8.193 USFWS 2001 Dirt Plant -Near -Subsurface 160 65 22 16 7.75 USFWS 2001 Cedar Rapids -Off -Surface 140 57 23 16 7.75 USFWS 2001 Cedar Rapids -Off -Subsurface 140 57 23 16 17.75 USFWS 2001 Cedar Rapids -Near -Surface 140 57 23 16 7.75 USFWS 2001 Cedar Rapids -Near -Subsurface 140 57 23 17 5.82 USFWS 2001 Bucks U U3-Off-Surface 70 34 10 17 5.82 USFWS 2001 Bucks U U3-Off-Subsurface 70 34 10 17 5.82 USFWS 2001 Bucks U U3-Near-Surface 70 34 10 17 5.82 USFWS 2001 Bucks U U3-Near-Subsurface 70 34 10 17 5.81 USFWS 2001 Bucks U L3-Off-Surface 70 34 10 17 5.81 USFWS 2001 Bucks U L3-Off-Subsurface 70 34 10 17 5.81 USFWS 2001 Bucks U L3-Near-Surface 70 34 10 17 5.81 USFWS 2001 Bucks U L3-Near-Subsurface 70 34 10 17 5.75 USFWS 2001 Bucks Lower -Off -Surface 140 62 8 17 5.75 USFWS 2001 Bucks Lower -Off -Subsurface 140 62 8 17 5.75 USFWS 2001 Bucks Lower -Near -Surface 140 62 8 17 5.75 USFWS 2001 Bucks Lower -Near -Subsurface 140 62 8 19 4.70 USFWS 2001 Elliott Upper -Off -Surface 84 49 17 19 14.70 USFWS 2001 Elliott Upper -Off -Subsurface 184 149 17 Subsurface Particle Surface Particle Size Size mm mm b Sample Size (% of largest Segment 1 River Mile Source Feature' d84 d50 d16 d84 d50 d16 clast 19 4.70 USFWS 2001 Elliott Upper -Near -Surface 84 49 17 19 4.70 USFWS 2001 Elliott Upper -Near -Subsurface 84 49 17 19 4.63 USFWS 2001 Elliott Lower -Off -Surface 82 148 14 19 4.63 USFWS 2001 Elliott Lower -Off -Subsurface 82 48 14 19 14.63 1 USFWS 2001 Elliott Lower -Near -Surface 82 48 14 19 14.63 1 USFWS 2001 Elliott Lower -Near -Subsurface 82 48 14 ' Abbreviations: XS is cross section; LP is longitudinal profile; RB is right bank; u/s is upstream; Avg is average. b Surface particle size statistics are based on pebble counts of the surface material in the vicinity of the corresponding subsurface sample for all studies identified, except for CES (1995). For CES (1995) data, surface particle size statistics describe bulk grab samples to a depth of 5 inches below the surface. These bulk samples are assumed to contain primarily the armor layer, but may also contain some subsurface material at sites where the d50 of surface particles is less than about 2.5 inches. A portion of many of the USFWS samples were measured gravimetrically in the field while the remainder of the samples were returned to the lab for processing. The Lower Lions samples (RM 12.0) were processed volumetrically, but no effort has been made to combine the data and construct complete subsurface bed material distributions. Current data for these samples are provided in Appendix D. 1 50 140 130 120 110 100 E E 90 y 80 m E 70 c 60 tn 50 40 30 20 10 0 i .......... • • •y 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 River Mile �—�— Subsurface - - + Surface Figure 2. d50 Sediment Sizes of Subsurface and Corresponding Surface Bed Material Distributions by River Mile on the Cedar River impractical and inadvisable. It is more prudent to identify the grain size range, depth of infiltration, and threatened developmental stage of fish in the stream being investigated (Lisle and Eads 1991). Detailed narrative criteria are also appropriate for developing indicators of aquatic habitat quality (Bauer and Ralph 2001). Table 7. Relationship between Chinook Salmon and Steelhead Trout Embryo Survival and the Percentage of Fine Sediments Present in the Streambed a/o Fines < 6.35 mm Embryo Survival Chinook Steelhead 0 98 95 10 98 93 20 97 86 30 86 74 40 50 45 50 15 18 60 2 7 Source: Bjorn & Reiser 1991 Integrated approaches to characterizing spawning gravel quality deserve wider consideration (Kondolf 2000). For example, Lisle (1989) investigated infiltration of fine sediment (c2 mm diameter) into clean gravel beds, bed material size distributions, scour -fill depths, and sediment transport during 10 storm flow events in three streams of north coastal California. Suspended sediments composed 75% to 94% of the total sediment loads during storm flows, but it was bedload between 0.25 mm and 2 mm that accounted for 70% to 78% of the fine sediment accumulated in clean artificial gravels planted in the streambed. Lisle (1989) also observed that sand formed a seal in the top several centimeters of gravel interstices that impeded deeper penetration of fine sand and silts into the bed during periods of even greater sediment transport. However, scour and fill processes during peak flow periods commonly scoured and/or filled the bed surface to depths of 10 cm or more, creating a sandy layer at least as thick as the seal formed by sediment infiltration. Therefore, scour could erode eggs laid in the bed and expose deeper levels of the bed to infiltration of fine sediment, but at the same time could allow fine sediment to be winnowed away. They observe great temporal and spatial variation in sediment patterns and conclude that individual storms of moderate size pose a threat to eggs laid in many areas selected by fish for spawning (Lisle 1989). Although no general agreement on numerical thresholds has been reached in the scientific literature, several values have been suggested and are in common use as default criteria for the development and advancement of policy. Thresholds of concern for "percent fines" in bed material vary by species and sediment grain size but most commonly fall around 20% (Lisle and Eads 1991). The most well known threshold in the Pacific Northwest may be the National Marine Fisheries Service (NMFS) "matrix" criteria for chinook salmon (NMFS 1996). The matrix assesses percent fines as one indicator of water/sediment quality. Cobble embeddedness is also used as an indicator of habitat quality. These parameters are used to characterize environmental baseline conditions and evaluate chinook habitat impacts to make effects USACEICEDAR RIVER GRAVEL Draft Phase I Methods and Data Report 04/15/02c _ 13 Cedar River Gravel Study determinations under the Endangered Species Act. The USFWS adopted similar criteria for bull trout (USFWS 1998). Values of percent fines and cobble embeddedness parameters used as threshold criteria by NMFS are summarized in Table 8. Table 8. NMFS Criteria for Fine Sediment Related Indicators of Watershed Condition and Function for Chinook Salmon Habitat Condition Not Properly Indicator Parameter Properly Functioning Functioning At Risk Functioning Sediment/ Percent fines <12% fines (<0.85 mm) 12% to 17% > 17% Turbidity Sediment/ Turbidity Low Moderate High Turbidity Substrate Embeddedness Dominant substrate is Gravel and cobble is Bedrock, sand, silt, or gravel or cobble subdominant, or if small gravel dominant, (interstitial spaces clear), dominant, or if gravel and cobble or embeddedness <20% embeddedness 20% to dominant, 30% embeddedness >30% 3.4.2.2 Fine Sediment in the Cedar River Several sources of information regarding fine sediment distributions and the effects of fine sediment on fish habitat in the Cedar River were identified in a review of the literature. Three sources presented bed material size distributions that contained fine sediment data. CES (1995) is a data report of sieve analyses on 74 bed material samples collected for the U.S. Army Corps of Engineers Seattle District. Data are cumulative, percent -finer -than distributions taken at 37 sample sites located along cross sections and longitudinal profiles at four general locations along the Cedar River (near RMs 20.5, 17.3, 11.05, and 5.05). At each of the 37 sites, bulk samples were obtained at depths of 0.0 to 0.4 feet and 0.4 to 0.75 feet (for a total of 74 samples) (Table 9). Samples were sieved and cumulative distributions determined gravimetrically (Table 5). The 37 near -surface samples contain a combination of surface armor and subsurface material and are identified as SA (containing surface armor) in Table 9. The 37 subsurface samples are the best data known to exist for an evaluation of fine sediment in the Cedar River because they exclude the coarser armor layer and reflect the bed material that most spawning, anadromous salmonids would encounter during redd construction. These data, collected in 1994, are also the most recent fine sediment data available. The data are apparently not directly related to a CES study that developed habitat preference curves and conducted spawning analyses to guide regulation of the river during spawning periods (CES 1991). (See additional discussion of salmonid spawning gravel preferences under Section 3.5, "Spawning History.") Stober and Graybill (1974) studied river utilization by spawning sockeye salmon, including depth and velocity preferences during low flow conditions. Bed material was characterized in 11 study reaches by collecting between four and eight samples using a 6-inch by 6-inch cylindrical core from each reach (see Table 5). Ten study reaches were distributed along the USACE/CEDAR RIVER GRAVEL 14 Draft Phase I Methods and Data Report 04/15/02e Cedar River Grave[ Study Table 9. Fine Sediment Observed in Bed Material Distributions during Other Studies of the Cedar River River Mile Segment Fraction Sampled' Source Percent Fines by Maximum Sediment Size mm b' 0.1 mm 0.6 mm 10.84 mmd 1 mm 2 nun 4 mm 6 mm 20.50 5 SA Stober and Gra bill 1974 3 6 19 29 20.46 5 SS CES 1995 4 7 8 14 19 24 20.46 5 SA CES 1995 3 4 5 8 11 14 20.45 5 SS CES 1995 3 5 6 10 15 19 20.45 5 SA CES 1995 0 0 0 0 0 1 18.00 6 SA Stober and Gra bill 1974 4 7 21 33 17.30 7 SS CES 1995 4 6 7 12 20 26 17.30 7 SA CES 1995 1 1 2 3 5 7 17.25 7 SS CES 1995 5 9 11 19 28 35 17.25 7 SA CES 1995 3 6 7 10 14 16 16.10 8 SA Stober and Gra bill 1974 3 6 17 32 14.18 10 SA Stober and Gra bill 1974 4 6 6 8 13.80 11 SA Stober and Gra bill 1974 6 10 21 29 13.20 11 SA Stober and Gra bill 1974 6 13 21 28 12.70 11 SA Stober and Gra bill 1974 13 18 27 35 11.45 13 SA Stober and Gra bill 1974 3 6 19 30 11.06 13 SS CES 1995 2 3 4 7 11 15 11.06 13 SA CES 1995 0 1 1 1 1 2 11.04 13 SS CES 1995 3 6 8 14 21 26 11.04 13 SA CES 1995 1 2 2 3 5 6 11.02 13 SS CES 1995 4 6 7 12 19 25 11.02 13 SA CES 1995 1 2 2 4 6 8 11.01 13 SS CES 1995 5 10 12 21 29 35 11.01 13 SA CES 1995 1 2 2 4 6 9 8.25 16 ISA Stober and Gra bill 1974 3 7 1 1 20 1 132 River Mile Segment Fraction Sampled' Source Percent Fines by Maximum Sediment Size mm b' ` 0.1 mm 0.6 mm 0.84 mmd 1 mm 2 mm 4 mm 6 mm 5.37 17 SA Stober and Gra bill 1974 3 8 27 38 5.06 18 SS CES 1995) 5 8 9 13 18 22 5.06 18 SA CES 1995 1 1 1 1 1 2 5.04 18 SS CES 1995 5 8 9 17 22 27 5.04 18 SA CES 1995 1 1 1 1 2 2 5.02 18 SS CES 1995 5 8 9 16 24 29 5.02 18 SA CES 1995 1 2 2 3 5 5 4.97 18 SS CES 1995 5 8 9 15 22 27 4.97 18 SA CES 1995 3 3 4 5 7 8 4.96 18 SS CES 1995 3 4 5 9 13 16 4.96 18 SA CES 1995 1 2 12 4 5 6 1.50 22 SA Stober and Gra bill 1974 4 8 22 32 1.18 22 SA SAIC 1997 5.6 52.2 0.91 22 SA SAIC 1997 28.4 61.9 0.46 22 SA SAIC 1997 10.4 79.4 0.10 22 SA SAIC 1997 17.2 67.3 0.003 22 SA SAIC 1997 6.0 49.9 ' SA indicates the sample includes some surface armor as well as subsurface material; SS indicates the sample is entirely subsurface material (excludes surface armor); subsurface strata are generally finer than particles that may cover or "armor" the bed surface. b Stober and Graybill (1974) data differ from column headings as follows: Percent Finer Than 6 mm is actually 6.73 mm; 2.0 mm is actually 1.68 mm; 0.6 mm is actually 0.42 mm; and 0.1 mm is actually 0.105 mm. ` SAIC (1997) data for Percent Finer Than 0.1 mm is actually 0.06 nun (the upper limit for silt); SAIC (1997) are composite samples where RM is measured at the midpoint of the channel sampled. d Compare to percent fines threshold criteria in "chinook matrix" (NMFS 1996) as follows: Percent Fines <0.85 mm Condition of Fine Sediment Processes in Watershed <12 Properly Functioning 12 to 17 Functioning At Risk >17 Not Properly Functioning river downstream of Landsburg dam, ranging from RM 20.5 to RM 5.37. Six of the 10 reaches were between RMs 16.1 and 11.45, and the eleventh reach centered at RM 1.5 in Renton. Cumulative distributions were determined volumetrically, averaged, and presented graphically as percent -finer -than -standard sieve sizes. These graphs were interpreted and fine sediment data incorporated in Table 9. Stober and Graybill (1974) report that the resulting distributions for the different reaches were similar, and that no "qualitative deficiencies" were apparent in the data. They indicate, however, that the number of samples per reach may not have been adequate to detect significant differences between reaches. In its report characterizing the chemistry of sediments in the lower Renton reach of the Cedar River, SAIC (1997) presents limited but useful sediment size data. Grain size distributions for composite substrate samples are presented for five subsections of the lower 1.278 miles of Segment 22. A total of 22 bed material samples were collected within 10 cm of the surface using van Veen samplers. Samples were composited into five samples by subsegment (Table 5). The depositional environment, particularly immediately adjacent to Lake Washington, makes the distinction between surface and subsurface samples of little fluvial and biological consequence. Fractions less than 2 mm, linearly from the mouth to upstream, are 58%, 91%, 90%, 85%, and 56%. Corresponding silt and clay fractions less than 0.06 mm are approximately 6%, 29%, 11%, 17%, and 6%, respectively. These data are included in a summary of fine sediment data in Table 9. The most complete source of data found regarding overall sediment recruitment, transport, and storage is the Cedar River Current and Future Conditions Report (King County 1993). The discussion of sediment sources has been incorporated later in this section (see Table 10), and the fate of sediments will be helpful in the development of a sediment budget in Phase 2. Fine sediment is not a primary objective of the report, however, and no fine sediment distributions are reported. Recent fisheries reports were also consulted with regard to the effects of fine sediment on salmonid habitat in the Cedar River, but neither Kerwin (2001) nor Weitkamp et al. (2000) reported results of any fine sediment studies. Additional review of these three sources is provided in Appendix E. In summary, three primary sources of fine sediment size distributions in the Cedar River were identified in the literature. Subsurface data obtained from CES (1995) provide the best characterization of fine sediments. All fine sediment data sources are described earlier in this report with subsurface data sources in Table 5. Data are presented as percent -finer -than cumulative distributions in Table 9. Fine sediment issues will be further addressed under Section 3.4.4, "Results and Discussion" below. 3.4.3 Methods Additional observations regarding fine sediments were recorded in the field as part of this study. During the float -trip reconnaissance, general observations were made of sediment sources and depositional areas along the river. Then at each surveyed cross section, qualitative, yet specific observations of fine sediment in the streambed were made. These observations include narrative characterizations of fine sediment in both riffles and pools consistent with watershed analysis protocols established by the Washington Forest Practices Board (WDNR 1994). In addition, USACE/CEDAR LIVER GRAVEL 15 Draft Phase 7 Methods and Data Report oa/Is/oze Cedar River Gravel Study cobble embeddedness (after Bunte and Abt 2001, Bain and Stevenson 1999) was visually classified into one of four numeric categories at each site. Percent fines were also summarized for each pebble count site as described below. Sediments smaller than 4 to 8 mm are sometimes not differentiated in pebble counts because of the difficulty of touching, retrieving, and measuring only one particle randomly and accurately. Though not as accurate as various bulk sampling methods (Schuett-Hames et al. 1999), pebble counts can still detect fine sediment on a streambed, which may indicate large quantities of fine sediment throughout a gravel deposit, or deposited over a gravel bed (Kondolf 1997, WDNR 1994). Since pebble counts are a common field procedure for characterizing bed material, grain size distributions developed in this study are also analyzed for fine sediments and presented for future reference. Pebble counts included classification of sediments into sizes of <=1 mm, 1 to 2 mm, 2 to 4 mm, 4 to 6 mm, 6 to 8 mm, and 8 to 12 mm and larger. When more than one small particle was blindly retrieved from a sheltered pocket or margin of the bed, either by pinching or by adhering to a finger, a particle was selected for measure that was representative of the modal grain size of the particles and which seemed to the surveyor to be consistent with the texture felt on the bed when the particles were retrieved. The intermediate axis of the selected particle (or the apparent diameter for very small or well-rounded grains) was measured to the nearest millimeter. Once grain size distributions were developed for the pebble counts, percentages of the distributions finer than 1 mm, 2 mm, 4 mm, and 6 mm were recorded. In addition, surface sediment distributions obtained from other studies were evaluated and summarized according to sizes consistent with the size classes in their samples. 3.4.4 Results and Discussion Cumulative percent fines in the Cedar River identified in other studies (described earlier) are presented for a range of maximum sediment sizes in Table 9. Some of the subsurface data in Table 9 are plotted against NMFS fine sediment criteria by river mile in Figure 3. The appropriate distribution for comparison with the NMFS threshold is the distribution up to and including 0.84 mm particles (the bold red line with solid triangular data points in Figure 3). All cumulative percentages of subsurface sediment less than 0.85 mm are well within NMFS criteria for a properly functioning system. Sediments up to 2.0 mm are also not plentiful in the bed material sampled, with cumulative percentages less than 12% in about one-third of samples, and never greater than about 20% in any sample. The distribution less than or equal to 0.6 mm that contains some surface armor (the fine dotted green line with open squares in Figure 3) includes data for river miles sampled by Stober and Graybill (1974) that were not sampled by CES (1995). In all instances, Stober and Graybill's data result in greater percentages finer than 0.6 mm than similar distributions observed in the CES data. Stober's data suggest even higher cumulative percentages less than the 0.84 mm diameter that may have exceeded the NMFS properly functioning criteria, particularly at stations between RM 12 and RM 14. This may have indicated a fine sediment source at that time (e.g., high sand bluff at RM 14.2) that is no longer active today. It may also reflect a difference in USACEICEDAR RIVER GRAVEL 16 Draft Phase l Methods and Data Report 04115/02e Cedar River Gravel Study Table 10. Fine Sediment Sources and Indicators of Fine Sediment Accumulation on the Bed Surface of the Cedar River and its Tributaries Selected Indicators of Fine Sediment Accumulation Percent Fines by Maximum Sediment Size Sediment Cobble Source Sediment in Sediment in Embedded - Segment River Mile Schematic Feature <1mm <2mm <4mm <6mm Riffles Pools ness Source 23.58 XS, no margin 1 3 5 7 Local N/A <15% This study 23.43 Lateral bar 3 4 6 8 This study 1 23.305 XS, no margin 0 5 10 12 Local Widespread <15% This study 23.3 old slump scar on left bank This study 23.21 Lateral bar 0 0 0 0 This study 23.2 Riffle 0 0 0 Inter-Fluve 2001 23.155 XS, at upper limit of Landsburg pool, no margin nd nd nd nd Most of bed Widespread >35% This study 22.945 XS,in Landsburg reservoir, complete nd nd nd nd N/A Widespread >35% This study 2 22.78 Bar u/s dam 4 4 4 Inter-Fluve (2001) 22.76 XS, in Landsburg reservoir, complete nd nd nd nd N/A Widespread >35% This study 22.74 Bar u/s dam 5 6 6 Inter-Fluve 2001 22.0 Gravel mitigation placement site (Golder) (Golder (2001) 4 21.61 XS, complete 5 11 16 17 Local Local <15% This study 21.261 XS, complete 4 6 10 13 Local Patches 15% - 35% This study 21.1 Gravel cliff up to 30m high This stud 20.75 4 70-120 gravel banks, LB from RM 20.6 to 20.9, major gravel source This study 20.493 20.432 XS, complete A\,/ Walsh Lake Diversion Ditch, severe erosion, coarse & fine 'N/ 11 11 12 14 Local Local <15% This study 5 sed. King Co (1993) 19.865 XS, complete 0 0 0 3 Local N/A <15% This study 19.7 4 gravel cliffs 5-12m high This study 19.3 14 50m high, steep bank, stabilized since 1992 This stud 18.8 4 3m high gravel bank This study 18.546 XS, complete 0 0 1 1 Local N/A <15% This study 6 18.517 A-\_/ Rock Creek, no observed erosion, coarse & fine sediment 1 1 1 3 This Study; King Co (1993) 18.145 XS, no margin 0 0 0 0 Local N/A None This study 18.1 35m hi h banks with sm. gravellsand This stud 17.592 XS, complete 2 4 7 7 Local N/A <15% This study 7 17.3 50' high clay cliff with sand This study 17.163 XS, complete 0 0 0 1 Local N/A <15% This stud 16.159 XS, complete 0 1 3 3 Local Local <15% This study 8 15.869 A-\_/ Dorre Don live side channel, increasing erosion potential ��� 5 5 5 7 This Study; King Co (1993) 15.765 XS complete 3 3 3 4 Local N/A 15% - 35% This stud 14.906 XS, complete 1 1 3 5 Local N/A nd This study 9 14.757 XS, complete 0 1 1 1 Local N/A <15% This study 14.757 Low lateral bench 2 3 4 5 This stud 10 14.575 14.447 XS, complete *N,-/ 7 9 12 12 Local Patches 15% - 35% This study Peterson Creek, large tributary source of coarse and fine sed. 1 2 3 4 This Study; King Co (1993) 14.2 ff hi h sand blurevetment barrier prevents transport to stream This stud 14.012 XS, complete 4 5 6 8 Local N/A <15% This study 13.408 Taylor Creek, fine sed. only, minor erosion w/inc. potential not nd nd nd This study 13,208 XS, no thalweg 3 5 6 7 Local N/A 15% - 35% This study 11 12.666 XS, no thalweg 0 0 0 0 Local NIA <15% This study 12.605 A\,/ Unnamed Creek, fine sediment only, estimated small total load 29 31 34 34 This study 12.5 8m high banks This study 12.2 Webster Lake, fine sediment only, potential for increasing erosion Kinq Co 1993 12 12.054 XS, no margin 4 4 6 6 Local N/A 15% - 35% This study 11.9 40m high bluff on RB from RM 11.8 to 12.0 reve etated This stud 13 11.6 Cedar Hills, fine sediment only, potential for increasing erosion King Co (1993) 11.366 XS, complete 5 9 9 9 Local N/A 15% - 35% This stud 10.942 XS, no thalweg 5 8 10 12 Local N/A <15% This study 10.942 Low lateral bench 2 5 10 12 This study 14 10.865 XS, complete 11 13 13 13 Local N/A <15% This study 10.6 15m high slope on RB from RM 10.5 to 10.7 This study 10.366 Point bar 2 2 4 4 This stud 15 10.1 25m high slope on RB from RM 10.05 to 10.15 This study 10 017 XS, complete 2 4 4 4 Local N.<A <15°% This stud 9.6 30m high slope on RB from RM 9.5 to 9.7 This study 9.252 XS, top of berm 4 9 11 11 Local Patches <15% This study 16 9.252 XS, w/ thalweg 7 12 14 17 Local Patches <15% This study 8.193 XS, no thalweg 14 14 17 18 Local Local 15% - 35% This study 7.395 XS, no thalweg 5 6 6 7 Local N/A 15% - 35% This stud 17 6.216 XS, no thalweg 3 4 5 6 Local N/A <15% This study 5.613 XS, complete 0 0 0 1 Local N/A <15% This stud 18 5.2 Madsen Creek, very deeply incised, fine sediment source only King Co (1993) 5.05 Elliott landslide on I00m high slope on RB from RM 4.95 to 5.15 - This stud 19 4.702 XS, no margin 7 12 16 19 Local N/A 15% - 35% This study 4.6 Steep slope on RB from RM 4.5 to 4.7 at least 30m high This stud 4.38 XS, no margin 9 11 13 14 Strands Widespread <15% This study 4.1 Molasses Creek, fairly stable, coarse and fine sediment --'_'N-/ King Co (1993) 20 3.9 1987landslide (30,000 c.y.) King Co (1993) 3.548 XS, no margin 11 15 16 18 Lg clasts N/A 15% - 35% This study 3.3 Maplewood Creek, incised, unstable, fine sediment source only Kinq Co 1993 2.392 Ginger Creek, bedrock, greatest trib. source coarse sediment King Co (1993) 2.286 XS, complete 4 7 7 7 Local N/A 15% - 35% This study 2.04 XS, in run, complete 3 9 11 Jones & Stokes (2000) 21 1.94 XS, in riffle, complete 2 2 3 Jones & Stokes (2000) 1.85 XS, in run, complete 7 8 9 Jones & Stokes (2000) 1.75 XS, in run, complete 2 3 8 Jones & Stokes (2000) 1.7 Eroding slide on LB contributes sand and fine gravel This stud 1.62 XS, in glide/pool, complete 20 27 33 Jones & Stokes (2000) 1.53 XS, in run, complete 5 8 10 Jones & Stokes (2000) 22 1.44 XS, in run, complete 3 3 8 Jones & Stokes (2000) 1.34 XS, in run, complete 3 7 15 Jones & Stokes (2000) 1.3 XS, in riffle, complete 2 2 7 Jones & Stokes (2000) 1.26 1 F XS, in run, complete 2 2 3 Jones & Stokes 2000 Key 'I Sediment source (schematic) Sediment in Riffles (in order of increasing fine sediment load& WDNR 1994) Sediment inputs from channel margin sources via bank erosion or mass wasting processes Local Locally within the lee of large clasts and other hydraulically -sheltered locations Sediment inputs from tributary streams Strands As strands extending downstream of large clasts Vertical arrow represents downstream flow of mainstem Cedar River Most of bed Over most of the channel bed Lg clasts As a thin draping over larger clasts composing the bed surface Feature Sediment in Pools (in order of increasing fine sediment load WDNR 1994) XS Cross section Local Local deposition in deepest pools text Text in normal font describes mainstem Cedar River features and fine sediment parameters Patches Fine sediment patches dominate larger pools, extending into pool tails text Text in italics describes tributaries and channel margin fine and coarse sediment sources Widespread Extensive deposition in nearly all pools Cobble Embeddedness (in order of increasing fine sediment loadNMFS 1996: t1SFS 2001)Embeddedness (in order of increasing fine sediment loadNMFS 1996: USFS 2001) <15% Visual estimate assumed equivalent to "Properly Functioning" (<20%) in NMFS matrix 15% - 35% Visual estimate assumed equivalent to "At Risk" (20% to 30%) in NMFS matrix >35% Visual estimate assumed equivalent to "Not Properly Functioning" >30% in NMFS matrix 30% 25% 20% 10% 5% 0% 22 20 18 16 14 12 10 8 6 4 2 0 River Mile Figure 3. Percent Fine Sediment Distributions in the Cedar River Relative to Fine Sediment Threshold criteria established by the National Marine Fisheries Service (NMFS 1996). NMFS criteria are established for subsurface distributions (SS) less than 0.85 mm (compare to SS 0.84 mm). Percent fines less than 0.6 mm and 2.0 mm are also shown, including the percent of fines less than 0.6 mm in a near -surface sample normally containing some surface armor (SA). sampling methodology. However, Stober and Graybill (1974) observe no "qualitative deficiencies" from the data. Table 10 presents additional approaches to describing fine sediment in the Cedar River, including surface "percent fines" data from pebble counts, narrative descriptions of fine sediment in riffles and in pools, and categorical representations of the embeddedness of small cobbles and coarse gravels in fine sediments. Percent fines and cobble embeddedness are parameters for comparison with chmook salmon threshold criteria that are summarized in Table 8 (NMFS 1996). Narratives for sediment accumulations in riffles and pools describe situations that may or may not be found in a naturally functioning river system with few disturbances. Table 10 also identifies locations of sediment input to the Cedar River identified by King County (1993) and during field data collection. Data indicate that fine sediment generally represents only a small proportion of the surface bed material. Fine sediment is present in greater proportions on the bed surface in Segments 4, 5, 14, 19, and 20 (Table 10), but these distributions are not necessarily inconsistent with natural fluvial transport of these materials. Segment 4 likely reflects fine sediments in the lee of coarser cobble and small boulder substrates at RM 21.61, and in an area of slightly finer substrate where numerous sockeye salmon were observed spawning. Fine sediments are marginally high in Segment 14, perhaps related to its position at the downstream end of several consecutive segments that were flatter and less confined than other segments upstream. Segments 19 and 20 exhibit high percent fines downstream of the Elliott landslide in Segment 18, but these effects are not observed further downstream in Segment 21 (Table 10). Often, at least one other recorded parameter also detects an increase in fine sediment on the bed (Table 10). Estimates of cobble embeddedness indicate a system functioning properly or functioning at risk under NMFS criteria; only in the pool upstream of Landsburg dam does cobble embeddedness reflect a situation that is not properly functioning. Besides the landslide, many of the potential sediment sources identified in Table 10 appear to have no detectable effect, or only local effects, on grain size distributions in downstream bed features. The data observed by CES (1995) represent both the best data for evaluation of fine sediment impacts and the most recent subsurface fine sediment data available. Even if Stober and Graybill's (1974) data suggest the potential for encroachment across the NMFS threshold, we conclude that fine sediment in subsurface bed material is not currently a significant limiting factor in salmonid production at the sites sampled. Fine sediment distributions observed on the bed surface do not appear to be inconsistent with transient storage of fine sediments under natural processes. 3.5 Spawning History 3.5.1 Scope of Work Under this task, annual spawning data are to be compiled for comparison to existing gravel distributions. These data will be analyzed to determine historical trends in spawning between different river reaches. USACE/CEDAR RIVER GRAVEL 17 Draft Phase I Methods and Data Report 04/I5/02e Cedar River Gravel Study 3.5.2 Data Sources In addition to data collected in the field during this study, information regarding spawning history and characteristics for a range of salmonids and Pacific Northwest rivers was reviewed in the literature. Material devoted specifically to the Cedar River and anadromous salmonids common to the river was given priority. Some of the more applicable literature sources reviewed are identified in Table 11. Table 11. Spawning Data and Reports Reviewed for Use in Cedar River Gravel Study Source Date/Purpose of Study Location Data Reported Burton, Foley, and 2000 and 1999 chinook Mainstem Cedar River d/s Densities by river mile, substrate Mavros 2000 redd surveys Landsburg and streamflow characteristics Burton and Little 2000 Cedar River steelhead Mainstem Cedar River d/s Steelhead densities by river mile, 2001) monitoring Landsburg escapement, flows R2 Resources 2001 Cedar River habitat Mainstem Cedar River d/s Excel file of individual habitat 2001) survey Landsburg to mouth unit data and descriptions Golder (2001b) 2000 salmonid spawner Renton reach and side Sockeye spawner and redd and redd survey channels near Elliott Park counts Jones & Stokes 1999 sockeye salmon Cedar River, Renton reach Sockeye spawner and redd 2000b spawner and redd survey counts Jones & Stokes 1999 chinook salmon Cedar River, Renton reach chinook spawner and redd 2000c spawner and redd survey counts Jones & Stokes 1998 salmon spawner and Cedar River, Renton reach chinook and sockeye spawner 1999 redd survey and redd counts Carrasco et at. 1998 chinook spawner Cedar River and Spawner counts, historic 1998 survey data 4 tributaries; WRIA 8 escapement CES (1991) 1986 to 1990 instream flow Cedar River u/s and d/s of Habitat preference data for and habitat preference Landsburg dam steelhead, sockeye, chinook, curve analyses coho; weighted usable area curves; instream flow history Stober and Graybill 1972, Relate effects of Cedar River, 11 short Spawner and redd distribution (1974) discharge on sockeye segments, most between and timing by reach, utilization spawning area Landsburg and lower Jones of spawning area, gravel depth Rd bride and velocity characteristics Quihillalt (1999) Trinity River chinook redd Trinity River, Northern Densities and trends by river surveys, 1996 through California mile, substrate and stream -flow 1998 characteristics Bjomn and Reiser Habitat requirements of General General substrate characteristics 1991 salmonids in streams, text Groot and Margolis Pacific salmon life General Substrate requirements for (1998) histories, text spawning, incubation, emergence by species Kondolf (2000) Assessing salmonid General Gravel requirements of salmonid spawning gravel quality life stages, grain size descriptors USACE/CEDAR RIVER GRAVEL 1 g Draft Phase I Methods and Data Report 04/I5/02e Cedar River Gravel Study 3.5.3 Methods 3.5.3.1 Defining Species of Interest This study is predicated on a suspected change in spawning gravel abundance and/or quality from that observed during a survey of spawning habitat on the river in the 1960s (see the historical review included in CES [1991]). One of the purposes of that survey was to develop a sockeye salmon escapement goal for the Cedar River, which has remained at 300,000 sockeye since that time. Sediment data from the 1960s study cannot be replicated since it was primarily a visual survey with minimal bed sampling, relying heavily on the surveyor's expertise (USACE 2001). Until recently, no other spawning habitat surveys were known to exist that resulted in escapement goals for sockeye or other salmonid species. R2 Resources (2001) completed a habitat survey of the mainstem Cedar River in 2001. A report is not yet available, and it is not clear whether the data are sufficient for use with hydraulic data to develop escapement estimates for various species in the river. Observations of spawning gravel since the 1960s have suggested that changes in the grain size distributions and locations of bed material may be partly responsible for declines in production for all anadromous salmonids (USACE 2001). However, little research has been conducted to quantify whether gravels present in the river represent an adequate volume or composition to support current or long-term salmonid spawning. Segment or reach specific locations where spawning frequency varies with bed material size distributions are undocumented. Although what constitutes good spawning gravel varies greatly among salmonid species, many studies observe that particles in the range of 13 to 102 mm should dominate the size distribution for salmonids in gravel -bedded streams (Table 12). There are definite departures from this range for many salmonids. Kondolf (2000) indicates that salmon often spawn in gravels and cobbles with diameters equal to approximately 10% of their body length. Larger chinook salmon can therefore accommodate a larger spawning substrate than coho and smaller bodied sockeye salmon. In fact, sockeye salmon can tolerate much finer sediment, spawning even in silty conditions. However, many other factors further define where various salmonids prefer to construct their redds, including flow type, water depth and velocity at the redd, and patterns of water upwelling and infiltration through the gravels (Table 12). Burton et al. (2000) observed a predominance of fall chinook redds in the larger substrate of riffles as opposed to the somewhat finer, more uniform spawning gravel typical of pool tails in the Cedar River (Table 13). One possible explanation is that the fall chinook are attempting to avoid the "nuisance" of spawning sockeye and the superimposition of sockeye redds (Burton pers. comm.). However, a USFWS study of gravel and scour characteristics in chinook spawning habitat focused on chinook redds observed in pool tails and not at or downstream of riffle crests (Peters 2001). These diverging views suggest that spawning habitat preferences, at least for fall chinook in the Cedar River, remain unclear. Upon evaluating 52 chinook redds and their proximity to sockeye redds, Burton et al. (2000) observed that 12% of chinook redds had sockeye redds superimposed on them, and an additional 44% of chinook redds had sockeye redds within 15 feet of them (Table 14). Conversely, a count of all sockeye redds within 20 feet of a chinook redd resulted in an average of 17% of them USACE CEDAR RIVER GRAVEL Draft Phase I Methods and Data Report oa1ts/oze 9 Cedar River Gravel Study superimposed on the chinook redd, and another 74% within 15 feet (Table 14) (Burton et al. 2000). Given the overlapping ranges of spawning gravels and the close proximity of sockeye and chinook redds, it is appropriate to focus this study on spawning substrate in general and not spawning area or a bed material size for a particular salmon species. Results from this study can then be applied to individual species based the occurrence of gravel and other preferential factors at a site. However, spawning preferences (intrariver escapement trends and redd counts) of various species and general habitat characteristics observed along the river are helpful for expanding hydraulic -sediment relationships observed during Phase 2 from the site scale to the segment scale, and for interpreting the effects of spatial and temporal sediment distributions on various salmonid species. Accordingly, preferential spawning data and habitat characteristics are further discussed below. 3.5.4 Results and Discussion 3.5.4.1 Historic Salmonid Escapement in the Cedar River Historic escapement rates of chinook salmon, sockeye salmon, and steelhead trout in the Cedar River are shown in Figure 4. Although native to the Cedar River, many chinook salmon were planted in the Cedar River between 1944 and 1965, and the highest chinook escapement values in the 1960s may reflect an increased proportion of hatchery stock (Burton et al. 2000). Stober and Graybill (1974) observed overutilization of some spawning areas (described below) during the peak sockeye salmon escapement of about 320,000 in 1973. It is unclear whether overutilization at this peak escapement is, in part, the justification for the development of the current sockeye escapement goal of 300,000 fish. Stober and Graybill (1974) expanded 1973 sockeye salmon escapement counts into spatial and temporal estimates of spawning gravel utilization. To do so, they applied male to female ratios and female spawning density to escapement counts obtained in three of four broad river segments. The three segments were each approximately 5.75 miles long, covering the then 17.3 miles between RM 4.3 and the Landsburg dam. Using the river miles and segments established for this study, Stober and Graybill's (1974) three broad segments correspond approximately to RM 4.3 to 10.1 (Segments 20 to 15); RM 10.1 to 15.9 (Segments 15 to 8); and RM 15.9 to 21.7 (Segments 8 to 4). Utilization results are presented as total area spawned within each of three broad river segments over the course of the 1973 spawning season. Percent utilization by segment is summarized in Table 15 for three biweekly periods beginning with peak utilization for the entire Cedar River (October 16). The researchers observed greater use of the middle segments (15 to 8) and upper segments (8 to 4) by spawning sockeye in terms of total area spawned for early, middle, and complete season totals. For example, spawning occurred predominately in the middle segments (15 to 8) and upper segments (8 to 4) from initiation of spawning (September 18) through the sixth week of surveys. Peak utilization was observed in the fifth week of spawning (October 16), when 55% and 36% of spawned area occurred in the middle segments (15 to 8) and upper segments (8 to 4), respectively (Table 15). Interestingly, the upper segments had more active spawners than the middle segments and lower segments (20 to 15), including more than twice as many spawners near current RM 20.5 than any of the 10 other sampling stations. However, the USACE/CEDAR RIVER GRAVEL 20 Draft Phase 1 Methods and Data Report 04/15/02e Cedar River Gravel Studv 1600 4-1 1400 a) E 1200 -0 a 1000 800 0 w 0 600 400 200 0 LO a ti r r r L o LO ti 00 00 r r r Year 10 Chinook ® Steelhead ❑ Sockeye o LC) CDG) a 0) � o T- T- N 350 c co 300 u,) 0 250 H c 200 a� 150 CU a� 100 a� 50 0 0 Figure 4. Historic Escapement of Chinook and Sockeye Salmon and Steelhead Trout in the Cedar River Chinook salmon data obtained or derived from Carrasco et al. (1998) and Burton et al. (2000); steelhead trout data obtained from Burton and Little (2000); sockeye salmon data from Stober and Graybill (1974). Table 12. Substrate, Velocity, and Depth of Flow Data 12:u ges 1'rom Studies Applicable to Cedar River Salmonids Study": Burton et al. 2000 Quihillalt 1999 Bjornn & Reiser 1991 CES 1991 Species: Chinook Chinook All salmonids Steelhead Sockeye I Chinook Coho Substrate Boulders >305 mm % 0.2 n/a n/a n/a n/a n/a n/a Large cobbles 152 to 305 mm % 1.8 4 to 5 n/a n/a n/a n/a n/a Small cobbles 76 to 152 mm % 27.4 20 to 22 n/a n/a n/a n/a n/a Large gravel 38 to 76 mm % 45.7 35 to 44 n/a n/a n/a n/a n/a Medium gravel 12 to 38 mm % 16.9 not defined n/a n/a n/a n/a n/a Small gravel 2 to 12 mm % 6.2 27 to 32 n/a n/a n/a n/a n/a Sand <2 mm % 1.8 3 to 8 n/a n/a n/a n/a n/a Preferred range forspawning, dominant sizes mm 38 to 152 -12 to 152 13 to 102 13 to 152 n/a 13 to 152 13 to 152 Preferred range for rearing, dominant sizes mm n/a n/a n/a 152 to >305 n/a n/a n/a Velocity Preferred range for spawning, dominant velocities (fps) 1.5 to 3.0 n/a Range 0.7 (sockeye) to 3.6 Chinook 1.9 to 2.9 0.5 to 2.7 1.3 to 3.5 0.75 to 2.0 Preferred range for rearing, dominant velocities (fps) n/a n/a Varies widely, typical 0.3 to 0.8 0.3 to 1.7 n/a 0.3 to 0.9 0.3 to 0.9 Depth of Flow Preferred range for spawning, dominant depths (feet) 0.9 to 2.1 n/a Range 0.5 (sockeye) to >1.0 Chinook 1.0 to 3.0 0.5 to 2.0 1.0 to 3.4 0.95 to 3.4 Preferred range for rearing, dominant depths (feet) n/a n/a Varies widely, typical 0.7 to 2.5 >0.8 n/a >1.5 >1.5 e See report text and citations for references n/a = not applicable upper segments were overutilized, resulting in the superimposition of redds and probable increases in egg -to -fry mortality due to dislodging of eggs and other density dependent factors. Underutilized early in the season, utilization of the lower segments (20 to 15) increased late in the spawning season and was greatest in the eighth week of spawning (November 6). The lower segments contained 53% of all spawning activity on November 13 (Table 15). Table 13. Stream Habitat Types for Observed Chinook Redds on the Cedar River Habitat Type 1999 Survey 180 redds 2000 Survey 53 redds Riffle 163(91%) 38 72% Glides 16 9% 14 (26% Pool Tailouts 1 1 0.5a/o 1 2% Source: Burton et al. 2000 Table 14. Sockeye Redds Observed in Close Proximity to Chinook Redds, Cedar River, 2000 Distance from < 5 5-10 10-15 15-20 >20 Chinook Redd Superimposed feet feet feet feet feet Percent of Chinook redds with any sockeye 12% 10% 17% 17% 2% 42% redds in close proximity (52 redds) Percent distribution of all sockeye redds 17% (11% on mounds, 9% 33% 32% 9% - within 20 feet of a Chinook redd 6% in its Source: Burton et al. 2000) Table 15. Distribution of Total Area Spawned' by Sockeye Salmon in Three Broad Segments of the Cedar River, 1973 Percent Utilization for All Spawning Sockeye by River Se mentsb and River Mile Lower Middle Upper Date Total Area Spawned (Utilization) ft2 x 1000 4.3 to 10.1 10.1 to 15.9 15.9 to 21.7 October 16 1,600 9 55 36 Peak week for utilization'' October 30 1,250 29 46 25 2nd highest week November 13 600 53 37 11 Reduced by 2/3 frompeak) ' Total area spawned is also termed "utilization'. Data from Stober and Graybill (1974). b The lower 4.3 mires of the Cedar River was not included due to underutilization of that segment. Lower includes Segments 20 to 15 in this study. Middle includes Segments 15 to 8. Upper includes Segments 8 to 4. Row totals (100%, not shown) represent all area spawned by sockeye salmon in the 17.3 miles of the Cedar River downstream of the Landsburg dam Values shown may not total 100% due to rounding. USACEICEDAR RIVER GRAVEL 21 Draft Phase 1 Methods and Data Report 04/15/02e Cedar River Gravel Study Stober and Graybill (1974) did not include the lower 4.3 miles of the Cedar River in their study (Segments 22 to 20 in this study) because spawning activity was observed to be "very low." Water depth and velocity were generally suitable for sockeye spawning near Renton and they hypothesized that the underutilization may partially result from reduced intragravel flows. Intragravel flow reduction in the naturally flatter, depositional reach could have been exacerbated by additional fine sediments deposited from surrounding development at that time (Stober and Graybill 1974). 3.5.4.2 Redd Locations Identified in the Cedar River Chinook salmon redd surveys have only occurred in the Cedar River since the listing of the Puget Sound stocks as threatened under the Endangered Species Act in 1999 (Burton et al. 2000; Jones & Stokes 1999, 2000c; Golder Associates 2001b; Foley pers. comm.). Steelhead trout redd surveys have occurred on a regular basis since about 1984, but most data are not readily available (Foley pers. comm.). Most of the mainstem river and some tributaries are surveyed under these efforts. Sockeye salmon redd counts have not been regularly performed and are often limited to specific segments of interest. Stober and Graybill (1974) counted redds at 11 stations along most of the length of the Cedar River downstream of Landsburg. Jones & Stokes (1999, 2000b) and Golder Associates (2001b) conducted sockeye and chinook salmon redd surveys in the Renton reach (Segments 21 and 22) and Elliott reach (Segments 18 and 19) of the Cedar River to monitor spawning responses to dredging (Renton) and side -channel construction for spawning (Elliott). Cedar River redd counts were translated into redd density distributions by river mile in Figure 5 as follows: ■ 1999 and 2000 chinook salmon redds by whole river mile (Burton et al. 2000); ■ 1999 and 2000 chinook salmon redds by study segment (river mile of upstream segment break) based on GIS coverage (Mavros 2002); ■ 1997 through 1999 steelhead trout redds by whole river mile (Burton and Little 2000); and ■ 1972 sockeye salmon redds in stations (river mile of station midpoint) (Stober and Graybill 1974). All of the above data indicate little use of the Cedar River for spawning downstream of RM 5.0. Chinook salmon spawning is variable between RM 5 and RM 12 but is consistently highest between RM 13 and RM 19. GIS data of chinook redds obtained for this study contain some known errors that may explain the variability between the chinook redd count data shown. Steelhead trout spawn fairly consistently in the river between about RM 9 and the Landsburg dam at RM 21.7 but only occasionally downstream of RM 9. The sockeye redd distribution from 1972 reflects the heavy utilization of the river upstream of about RM 10 described earlier in this section. Sockeye redd counts for 1998 to 2000 (Jones & Stokes 1999, 2000b, 2000c; Golder Associates 2001) are summarized for various locations within Segment 22 (the "Renton reach") in Table 16. Data represent the maximum number of redds observed in a "subsegment" during any weekly USACEICEDAR RIVER GRAVEL 22 Draft Phase I Methods and Data Report oan5ioze Cedar River Grave! Study 30% a� z j 25% 0 5 10 15 20 25 River Mile [ * Chinook, 1999, 2000 --N- Chinook, GIS -, Steelhead, 1997 - 1999 )(- Sockeye, 1972 Figure 5. Redd Counts for Chinook and Sockeye Salmon and Steelhead Trout in the Cedar River Chinook salmon data obtained Burton et al. (2000), except GIS data from Mavros (2002); steelhead trout data obtained from Burton and Little (2000); sockeye salmon data derived from Stober and Graybill (1974). survey throughout the spawning season (not the total redd count for a season). Most of Segment 22 receives regular spawning activity, especially upstream of the South Boeing bridge. These counts are comparable to redd counts observed by Stober and Graybill (1974) between RM 4.3 and 21.7, and they are in contrast to the lack of spawning activity observed in the "Renton reach" at that time. Chinook redds reported in Segment 22 in 1998 and 1999 (Table 16) were distinguished from sockeye redds by their larger size and greater depth (Jones & Stokes 2000c). Sockeye redd counts are also included in Table 16 for constructed groundwater and Elliot side - channel enhancement and mitigation projects in Segments 18 and 19 in 2000. Table 16. Maximum Number of Sockeye and Chinook Salmon Redds Observed in any Weekly Survey in the Lower Cedar River, 1998 to 2000 River Mile Description Socke a Salmon Chinook Salmon 1998a 1999b 2000` 19982 1999d 2000` 1.64 to 1.60 I-405 to Houser 545 3 21 1 0 0 1.60 to 1.52 Houser to Library 545 55 525 1 0 0 1.52 to 1.47 Library to Bronson 115 19 112 0 0 0 1.47 to 1.32 Bronson to Wells 840 98 422 0 0 0 1.32 to 1.25 Wells to Williams 333 55 256 0 0 0 1.25 to 1.09 Williams to Logan 30 124 207 0 2 0 1.09 to 0.76 Logan to S. Boeing Bride 129 62 481 0 0 0 0.76 to 0.0 S. Boeing Bridge to Lake Washington 110 17 2 0 0 0 1.64 to 0.0 Maximum Weekly Total for "Renton Reach" 1488 1413 2024 1 1 0 4.7 Groundwater Side Channel nd nd 69 nd nd 0 4.91 Elliott Side Channel nd nd 171 nd nd 0 a Data obtained from Jones & Stokes (1999) b Data obtained from Jones & Stokes (2000b) ` Data obtained from Golder Associates (2001b). Chinook salmon redd counts were not a specified monitoring objective of this study; no incidental observations of chinook salmon redds were reported. d Data obtained from Jones & Stokes (2000c) nd = no data 3.5.4.3 Habitat Characteristics R2 Resources (2001) conducted a Level H habitat survey of the Cedar River in the summer of 2001 during a 5-day float trip from Landsburg dam downstream to Lake Washington. Provisional data were obtained, related to river mile and study segment, and summarized by segment in Table 17. Spatial habitat data do not correlate precisely with study segments because some longer habitat units may straddle a segment break but are assigned wholly to one segment when calculated within a spreadsheet. For example, pool:riffle:glide ratios for Segments 18 and 19 in Table 17 that indicate all riffles and all pools, respectively, do not reflect actual USACE/CEDAR RIVER GRAVEL 23 Draft Phase 1 Methods and Data Report Dons/D2e Cedar River Gravel Study segment conditions on the ground. However, habitat indicators for segments (or paired, adjacent segments) are appropriate for use in this study. The percentage of the riverbed with cobbles (Table 17) is an indicator of the coarseness of the bed that may be used to differentiate the preference or utilization of certain segments for various salmonid species. Larger percentages of cobbles may indicate reduced overall usage of a segment for spawning by smaller fish. The highest percentages of cobbles may limit spawning by all species altogether. Estimates of ASA in riffles, glides, pools, and the overall segment are also presented in Table 17. Data are presented as a percentage of all area in specific habitat units (riffles, glides, and pools) occurring within a segment, as well as a percentage of the entire bed surface area within the segment. Riffle -glide -pool ratio is an indicator of habitat diversity within a segment. Riffles compose 70 to 100% of nearly all segments, and pools frequently compose less than 20% of segment area (Table 17). Optimal fish habitat is generally considered to include a balance between pool and riffle area, with each component making up 40 to 60% of the total stream habitat (Peterson et al. 1992). Glides are habitat units intermediate to riffles and pools. Although they have characteristics common to both, they provide little of the functional capabilities of either. Like pools, they are deeper, slow water habitats during low flow conditions, but they provide little cover or refuge during high flow events. Glides tend to be depositional zones, resulting in a fining of bed material relative to riffles, and are therefore less suitable for spawning. Greater pool frequencies are generally more desirable for fish habitat. NMFS (1996) criteria for a stream like the Cedar River suggest a frequency of 18 to 23 pools per mile is representative of a productive, naturally functioning system. Data indicate the Cedar River is significantly lacking in pools, with frequencies ranging from 0 to 4 pools per mile and typically between 1 and 2 pools per mile (Table 17). Based on the survey by R2 Resources (2001), Segments 8 and 15 appear to contain the most diverse habitat (or the closest balance between riffle and pool area). In addition to having the greatest pool area, Segment 15 also has one of the highest pool frequencies and contains the deepest pools. ASA in Segment 15 is among the highest observed at a segment scale at 33% and is adjacent to Segment 14 with ASA of 45%. Habitat characteristics at pebble count and cross section locations surveyed during this current study are summarized in Table 18. This information includes primary habitat unit or type, secondary or nested habitat unit, ASA, factors limiting ASA, and incidental fish observations during field surveys. ASA at each site is displayed by river mile in Figure 6. ASA is related to the d84, d50, and d16 grain sizes at each site in Figure 7. Our ASA estimates are consistently higher than those reported by R2 Resources (2001) in Table 17, largely because of differences in the area evaluated. Our estimates apply only to the area bisected by the channel cross sections, with width equal to the wetted width, and length equal to two times the bankfull width. R2 Resources estimates of ASA incorporate all areas within each reach and habitat unit, including more features prohibitive to spawning. For USACE/CEDAR RIVER GRAVEL 24 Draft Phase I Methods and Data Report oan5/o2e Cedar River Grave! Studv Table 17. Cedar River 2001 Habitat Survey Data' Summarized by Segment and River Mile Segment Number From RM: To RM: Segment Length miles Riffle:Glide: Pool Ratio Number of R:G:P Habitat Units Surveyed b(pools/mile) Pool Frequency Average Channel Width feet Average Maximum Depth feet Maximum Depth feet Percentage of Bed with Cobbles % Available Spa ninArea as Measured in: Riffles, as a Percent of All Riffle Area Riffles, as a Percent of All Area in Segment Glides, as a Percent of All Glide Area Glides, as a Percent of All Area in Segment Pools, as a Percent of All Pool Area Pools, as a Percent of All Area in Segment All Area in Segment 1` 23.665 23.180 2` 23.180 22.71 0.470 3 22.71 22.15 0.560 100:0:0 2:0:0 0.0 74 6.5 8.0 58 0.0 0.0 0 4 22.15 121.000 1.150 78:18:4 6:2:1 0.9 77 5.0 5.9 42 2.5 2.0 0.0 0.0 0.0 0.0 2 5 21.000 19.098 1.902 93:0:7 10:0:3 1.6 91 5.3 12.7 35 4.5 4.2 0.0 0.0 4 6 19.098 18.000 1.098 83:0:17 4:0:3 2.7 88 6.0 9.4 28 6.9 5.7 31.0 5.4 11 7 18.000 16.573 1.427 95:0:5 7:0:1 0.7 87 5.6 7.9 15 7.8 7.4 0.0 0.0 7 8 16.573 15.598 0.975 78:0:22 2:0:2 2.1 72 7.0 8.8 15 10.3 8.0 0.0 0.0 8 9 15.598 14.750 0.848 90:0:10 4:0:1 1.2 103 3.8 5.1 8 0.0 0.0 0.0 0.0 0 10 14.750 14.064 0.686 84:0:16 2:0:2 2.9 99 6.0 7.2 21 0.0 0.0 72.3 11.3 11 11 14.064 12.138 1.926 92:8:0 7:1:0 0.0 91 5.6 8.6 20 22.3 20.5 41.6 3.4 24 12 12.138 11.689 0.449 84:0:16 1:0:1 2.2 76 6.7 6.7 63 8.8 7.4 0.0 0.0 7 13 11.689 11.012 0.677 73:20:7 3:1:1 1.5 78 4.9 5.9 34 18.8 13.7 31.9 6.3 0.0 0.0 20 14 11.012 10.226 0.786 91:0:9 5:0:1 1.3 86 6.6 8.4 19 49.8 45.2 0.0 0.0 45 15 10.226 9.625 0.601 70:0:30 3:0:2 3.3 84 10.3 16.0 9 16.9 11.8 70.8 21.1 33 16 9.625 6.694 2.931 87:0:13 11:0:4 1.4 102 6.0 8.4 18 10.0 8.7 24.8 3.2 12 17 6.694 5.210 1.484 83:17:0 7:2:0 0.0 99 4.9 12.9 13 12.1 10.1 0.0 0.0 10 18 5.210 4.841 0.369 100:0:0 2:0:0 0.0 78 4.0 5.0 23 22.0 22.0 22 19 4.841 4.576 0.265 0:0:100 0:0:1 3.8 60 6.5 6.5 5 55.1 55.1 55 20 4.576 3.250 1.326 69:16:15 5:2:2 1.5 99 4.7 6.5 8 13.2 9.1 1.3 0.2 87.7 12.8 22 21 3.250 1.633 1.617 77:17:6 6:2:1 0.6 99 4.0 6.8 8 18.5 14.2 0.0 0.0 45.8 3.0 17 22 1.633 0.0 1.633 50:17:33 3:2:1 0.0 114 3.2 3.4 4 5.9 2.9 0.3 0.1 0.0 10.0 3 ' Habitat survey conducted by R2 Resources (2001). Data should be considered provisional and subject to revision. b With the riffle:glide:pool (R:G:P) ratio, the numbers of riffle, glide, and pool habitat units are simple indicators of habitat diversity. ` No surveys were conducted upstream of Landsbur dam. Table 18. Habitat and Fish Observations at Cross Section Survey Sites on the Cedar River Segment Number Site Number RM Primary (Secondary) Habitat Unit Available Spawning Area % Reason for Reduced Available Spawning Area Fish Observed near Cross Section Survey Other Fish Observed in Segment 1 1 23.58 Riffle 80 Fine sediment in margins; large substrate and high velocity at u/s end None 1 2 23.305 Riffle (Pool) 55 Left bank thalweg and pool depth (40%); fine sediment in right bank margin 5% One 6-in. trout 2 3 23.155 Glide 5 Fines and low velocity 2 small trout, 2 to 6 in. 2 4 22.945 Glide (Pool) 0 Substrate covered by fine deposition in Landsburg pool 3 small trout 2 5 22.76 Pool 0 Fine sediment deposition None 4 6 21.61 Riffle 0 Large substrate 1 salmonid, 2.5 in.; 5 to 10 trout, 4 to 8 in. 4 17 21.261 Riffle Glide 50 Fines, boulders, chute = —50% of total area 4 small trout, 2 to 4 in. 5 8 20.493 Riffle 80 No data 1 scul in, 3 in. 4 adult sockeye 5 9 19.865 Riffle 0 High velocity, large substrate 2 salmonids, 4 to 6 in. 2 adult sockeye 6 10 18.546 Riffle 40 No data None 6 11 18.145 Glide 65 No data 1 adult sockeye, 2 redds 7 12 17.592 Riffle 50 Large substrate None 7 13 17.163 Riffle 10 Large substrate 1 adult sockeye 2 adult sockeye 8 14 16.159 Riffle 5 No data None 18 adult sockeye, 3 resident trout, 8 in. 8 15 15.765 Glide Riffle 60 Large substrate None 9 16 14.906 Riffle 25 Too coarse None 9 17 14.757 Riffle 75 No data None None 10 18 14.575 Riffle 60 High velocity, large substrate None 1 trout(?), 3 in. I 1 19 14.012 Riffle Glide 65 High velocity, large substrate None 11 20 13.208 Glide (Riffle) 50 Estimated 60% of area, then less —10% for excess fines and compaction 6 adult sockeye Primary Available Other Fish Segment Site (Secondary) Spawning Area Reason for Reduced Available Fish Observed near Observed in Number Number RM Habitat Unit % Spawning Area Cross Section Survey Segment 11 21 12.666 Riffle 35 High velocity in upstream riffle and large —24 adult sockeye substrate 12 22 12.054 Glide 75 Channel margins only None 13 23 11.366 Glide (Riffle) 85 No data 1 trout, 6 in. 14 24 10.942 Riffle 65 Deep left bank margin with large substrate None —20 adult sockeye 14 25 10.865 Glide 70 Large substrate in left channel margin 1 scul in, 4 in. 15 26 10.017 Riffle 30 High velocity, large substrate 5 juvenile salmonids, 3 in. 16 27 9.252 Riffle (Pool) 40 Backwater pool behind bar, 50% of fast —6 juveniles, 0.5 to 2 in. riffle on right bank unavailable due to packed bed and larger substrate. 16 28 8.193 Glide (Riffle) 60 Deep trough with larger substrate on left None margin 16 29 7.395 Riffle 70 Large substrate along left margin and in None thalwe 17 30 6.216 Riffle 25 Larger substrate throughout, and high 3 adult sockeye; 1 adult velocity in d/s left comer of transect chinook; 1 unidentified fry —2 in. 17 31 5.613 Riffle 85 Subtract margins only None —24 adult sockeye 19 32 4.702 Riffle 60 Packed gravel in margins, extra fines, Many 1.5-in. sculpins medial gravel bar; steep, fast riffle near lower end of cross-section 20 33 4.38 Riffle (Glide) 40 Steep riffle, large substrate, very sandy Many 1 to 2-in. sculpins margins 20 34 3.548 Glide Riffle 75 Fines sand 4 sculpins 21 35 12.286 Riffle 75 Bed very packed 1 None Cn TI CD CD cD D v m 7D v cQ D CD v D D v cn v c�D 0 (D Z) v cc tD 0 m v cn m D m v v v 23.6 23.3 23.2 22.9 22.8 21.6 21.3 20.5 19.9 18.5 18.1 17.6 17.2 16.2 15.8 14.9 < 14.8 14.6 14 0 13.2 12.7 12.1 11.4 10.9 10.9 10 9.25 8.19 7.4 6.22 5.61 4.7 4.38 3.55 2.29 Available Spawning Area (% of Survey Transect Area) mw.�C.nM --jc000 0 0 0 0 0 0 0 0 0 0 0 j i - - f - 100 90 Q Q 80 �► ■ ■ 70 60 Q 50 N—O ■ '- a 40 0 20 10 0 0 0 0 0 0 0 CD 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 N CO t Ln CD ti CO 0) O N CO d- Ln CD r- CO 0) O — N CO It LO CD t,- CO 0) O = N CO = = = = = = = N N N N N N N N N N CO CO CO CO Sediment Grain Size (mm) �d50 ■ d84 d16 Figure T Available Spawning Area (ASA) as a Function of the d84, d50, and d16 Grain Sizes at Each Survey Site example, where our estimates apply to cross section survey areas often located near riffle crests, R2 Resources data incorporate chutes, steeper riffle areas, and pools where ASA may be limited. Observer bias probably also contributes to some differences in ASA estimates between studies. 4 LITERATURE CITED Bain, M. B. and N. J. Stevenson (eds). 1999. Aquatic habitat assessment: common methods. American Fisheries Society. Bethesda, MD. Bauer, S. B. and S. C. Ralph. 2001. Strengthening the use of aquatic habitat indicators in Clean Water Act programs. Fisheries (26) 6: 14-24. Bjornn, T. C. and D. W. Reiser. 1991. Habitat requirements of salmonids in streams. Influences of forest and rangeland management on salmonid fishes and their habitats. In Meehan, W. R. (ed.), American Fisheries Society Special Publication 19. 5: 83-138. Booth, D. B. 2000. Geology and geomorphology of stream channels course manual. Subsurface sediment sampling section. University of Washington Engineering Professional Programs. Seattle, WA. Bunte, K. and S. R. Abt. 2001. Sampling surface and subsurface particle -size distributions in wadable gravel- and cobble -bed streams for analyses in sediment transport, hydraulics, and streambed monitoring. (Gen. Tech Rep. RMRS-GTR-74.) U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. Fort Collins, CO. Burton, Karl. Fish biologist. Seattle Public Utilities, Seattle, WA. August 16, 2001 — comments during Cedar River float trip regarding characteristics of habitat used by various salmonids. Burton, K., S. Foley, and B. Mavros. 2000. Cedar River chinook salmon (Oncorhynchus tshawytscha) redd survey report, 2000: spawning habitat characteristics, spatial and temporal redd distributions, and the incidence of spawning sockeye in the vicinity of incubating chinook. Seattle Public Utilities. Seattle, WA. Burton, K. and R. Little. 2000. Cedar River steelhead monitoring program, annual report, 2000. Seattle Public Utilities. Seattle, WA. Carrasco, K., S. Foley, B. Mavros, and K. Walter. 1998. 1998 chinook spawner survey data technical report for the Lake Washington watershed. King County Department of Natural Resources. Seattle, WA. CES (Cascade Environmental Services, Inc.). 1991. Cedar River instream flow and salmonid habitat utilization study, final report. Prepared for Seattle Water Department. October. . 1995. Cedar River sediment study, report of sieve analysis. Graphical representations of 74 grain size distributions. March 20. Prepared for U.S. Army Corps of Engineers, Seattle District. Seattle, WA. USACE/CEDAR RIVER GRAVEL 25 Draft Phase 1 Methods and Data Report 04/I5t02e Cedar River Crave! Study Everest, F. H., R. L. Beschta, J. C. Scrivener, K. V. Koski, J. R. Sedell, and C. J. Cederholm. 1987. Fine sediment and salmonid production: a paradox. In E. O. Salo and T. W. Cundy (eds.), Streamside Management, Forestry and Fishery Interactions. Institute of Forest Resources Contribution No. 57. University of Washington. Seattle, WA. Foley, Steve. Fish biologist. Washington Department of Fish and Wildlife. February 1, 2002— telephone conversation regarding historical escapement data for Chinook salmon, sockeye salmon, and steelhead trout. Golder Associates. 2001a. USACE Section 205 Cedar River flood damage reduction project: Landsburg gravel supplementation, 2001 monitoring results. September. Redmond, WA. _. 2001b. 2000 salmonid spawner survey results for lower Cedar River and constructed side -channels. May 10. Redmond, WA. Groot, C. and L. Margolis (eds.). 1998. Pacific salmon life histories. UBC Press. Vancouver, BC. Havis, R. N., C. V. Alonso, J. G. King, and R. F. Thurow. 1993. A mathematical model of salmonid spawning habitat. Water Resources Bulletin 29:435-444. Inter-Fluve, Inc. 2000. Preliminary assessment of sediment trapping potential of Cedar River Landsburg diversion. March. Hood River, OR. Jones & Stokes. 1999. Cedar River Section 205 flood damage reduction project, salmon redd monitoring, Renton, Washington. January. Bellevue, WA. . 2000a. Cedar River Section 205 flood damage reduction project, scour chain monitoring second -year report. November. Bellevue, WA. _. 2000b. Cedar River Section 205 flood damage reduction project, sockeye salmon redd monitoring, Renton, Washington. January. Bellevue, WA. _. 2000c. Cedar River Section 205 flood damage reduction project, Chinook salmon redd monitoring, Renton, Washington. January. Bellevue, WA. _. 2001. Cedar River gravel study sampling plan. Bellevue, WA. Submitted to U.S. Army Corps of Engineers, Seattle District on September 12, 2001. Kerwin, J. 2001. Salmon and steelhead habitat limiting factors report for the Cedar — Sammamish Basin (Water Resource Inventory Area 8). Washington Conservation Commission. Olympia, WA. King County. 1993. Cedar River current and future conditions report. King County Department of Public Works, Surface Water Management Division. Seattle, WA. . 2001. Cedar River facilities ArcView GIS coverage. Electronic shapefiles received August 2001. USACE/CEDAR RIVER GRAVEL 2L Draft Phase / Methods and Data Report 03/15/02e V Cedar River Gravel Study 2002. Cedar River chinook salmon redd count locations for 1999 and 2000 in two ArcView GIS coverages. Electronic shapefiles received January 2002. Kondolf, G. M. 1997. Application of the pebble count: notes on purpose, method, and variants. Journal of the American Water Resources Association 33(1): 79-87. Kondolf, G. M. 2000. Assessing salmonid spawning gravel quality. Transactions of the American Fisheries Society 129: 262-281. Lisle, T. E. 1989. Sediment transport and resulting deposition in spawning gravels, North Coastal California. Water Resources Research 25(6): 1303-1319. Lisle, T. E. and R. E. Eads. 1991. Methods to measure sedimentation of spawning gravels. (Res. Note PSW-411.) Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture. Berkeley, CA. Mavros, William. Senior ecologist. King County Department of Natural Resources, Seattle, WA. January 14, 2002 — email with attached ArcView shape files of 1999 and 2000 chinook salmon redd locations. NMFS (National Marine Fisheries Service). 1996. Making Endangered Species Act determinations of effect for individual or grouped actions at the watershed scale. National Marine Fisheries Service Environmental and Technical Services Division Habitat Conservation Branch. Perkins, S. J. 1994. The shrinking Cedar River: channel changes following flow regulation and bank armoring. In Proceedings, Effects of Human -Induced Changes on Hydrologic Systems, American Water Resources Association 1994 Annual Summer Symposium, p. 649-658. Peters, R. 2001. Facsimile memorandum to Mike Wolanek, Jones & Stokes, detailing chinook salmon scour and gravel study objectives, including sampling locations and data availability. August 14. Peterson, N. P., A. Hendry, and T. P. Quinn. 1992. Assessment of cumulative effects on salmonid habitat: some suggested parameters and target conditions. (TFW-F3-92-001.) Washington Timber, Fish and Wildlife. Quihillalt, R. R. 1999. Mainstem Trinity River fall chinook salmon spawning redd survey, 1996 through 1998. U.S. Fish and Wildlife Service, Arcata Fish and Wildlife Office. Arcata, CA. R2 Resources. 2001. Level II habitat survey data for the Cedar River from the Landsburg dam to Lake Washington, summer 2001. Provisional data obtained August 2001. SAIC (Science Applications International Corporation). 1997. Sediment characterization of lower Cedar River, Renton, Washington. December. Bothell, WA. Schuett-Hames, D., R. Conrad, A. Pleus, and M. McHenry. 1999. TFW monitoring program method manual for the salmonid spawning gravel composition survey. Prepared for USACE/CEDAR RIVER GRAVEL 27 Draft Phase 1 Methods and Data Report 04/15/02c Cedar River Gravel Study Washington State Department of Natural Resources under the Timber, Fish, and Wildlife Agreement. (TFW-AM9-99-0001. DNR #101.) March. Stober, Q. J., and J. P. Graybill. 1974. Effects of discharge in the Cedar River on sockeye salmon spawning area. City of Seattle Water Department. Seattle, WA. USACE (U.S. Army Corps of Engineers). 2001. Scope of work: Cedar River gravel study Phases 1 and 2, field characterization and analysis of Cedar River gravel. Contract No. DACW67-00-D-1011, Delivery Order 10. July 17. Seattle District. Seattle, WA. USFWS (U.S. Fish and Wildlife Service). 1998. A framework to assist in making Endangered Species Act determinations of effect for individual or grouped actions at the bull trout subpopulation watershed scale. February. . 2001. Pebble count and bulk sediment sample data for 1999 and 2000 chinook salmon study on Cedar River. Five separate Microsoft Excel files received from Roger Peters. USGS (U.S. Geological Survey). 2001. Landslides triggered east of Puget Sound, Washington, by the Feb. 28, 2001 Nisqually Earthquake. Available: <http://geohazards.cr.usgs.gov/wa/report2.html>. Last modified March 8, 2001. Accessed January 15, 2002. WDNR (Washington Department of Natural Resources). 1994. Washington Forest Practices Board manual: standard methodology for conducting watershed analysis, version 2.1. November. Washington Forest Practices Board. Weitkamp, D. E., G. T. Ruggerone, L. Sacha, J. Howell and B. Bachen. 2000. Factors affecting chinook populations. City of Seattle. Lead preparer, Parametrix, Inc. Kirkland, WA. Wolman, M. G. 1954. A method of sampling course bed material. Transactions of the American Geophysical Union 35: 951-956. USACE/CEDAR RIVER GRAVEL 28 Draft Phase ] Methods and Data Report aids/oze Cedar River Gravel Study Append& A Changes in Segment Break Locations during Field Sampling Appendix A Changes in Segment Break Locations during Field Sampling Segments identified in the Cedar River Gravel Study Sampling Plan (Jones & Stokes 2001) were modified during field data collection at two sites. First, the break between Segments 1 and 2 was moved upstream approximately 250 feet to the upstream limit of the observed backwater effect of the Landsburg dam. Site 3, originally intended to be in Segment 1, was surveyed in its planned location in Segment 2. Moving the segment break resulted in more accurate description of the influences on sediment transport. Second, the break between Segments 10 and 11 was moved upstream approximately 300 feet to the crest of a steep riffle just west and upstream of SR 169. The move accommodates Site 19 at an alternative, adjacent cross section upstream of the one originally proposed for Segment 11. The upstream cross section, identified as an acceptable alternative in the Sampling Plan (Jones & Stokes 2001), was located in the tail of a large scour pool under the Cedar River Trail bridge. The pool tail was observed to contain slightly smaller gravels than the downstream cross section, had a lower velocity, and was located in an area frequently spawned by sockeye and steelhead (Burton pers. comm.). USACE/CEDAR RIVER GRAVEL Draft Phase 1 Methods and Data Report 04/15/02e A-1 Cedar River Gravel Study Appendix B Additional Sources of Cedar River Cross Section Data Appendix B Additional Sources of Cedar River Cross Section Data A U.S. Fish and Wildlife Service study surveyed between two and six cross sections as well as longitudinal profiles in 1999 and 2000 at each of the following seven study sites (upstream to downstream): ■ either side of the second Cedar River Trail crossing south of Maple Valley, ■ just downstream of the SR 169 and Cedar River Trail crossings north of Maple Valley, ■ Lion's Club, ■ Dirt Plant, ■ Cedar Rapids, ■ Buck's Curve, and ■ Elliott Park (Peters 2001). Cross section data have not been processed since low annual flows did not support the study's objectives of relating cross section and gravel characteristics to the depth of scour indicated by scour chains installed at each of the sites. The data are available for additional analysis if needed in this study. The cross sections are generally located in pool tails at known chinook salmon redd locations. Jones & Stokes repeated surveys of channel cross sections annually in 1998, 1999, and 2000 (Jones & Stokes 2000a). The cross sections were used with scour chains and pebble counts to assess channel responses in the 1-mile reach upstream of dredging which occurred in the lower 1.25 miles of the river. Cross section data are published and available for evaluation in hardcopy and spreadsheet format. However, the cross sections are located within Segment 22, where deposition dominates fluvial processes over the long term, or within Segment 21, a lower gradient, transitional zone upstream of I-405 in Renton. These study cross sections are also situated near existing flood study cross sections with very similar form in these channelized, confined segments. Incorporation of these cross sections into the City of Renton HEC-RAS model is outside this scope of work and probably would not significantly contribute to the application of model results (hydraulic characteristics) to gravel quality. Golder Associates (2001 a) is monitoring channel changes associated with a gravel augmentation project required as mitigation for the dredging referenced above. In summer 2000, 10,000 cubic yards of gravel from dredged spoils was placed as a berm along the right bank of Segment 4 downstream of the Landsburg bridge. The berm, approximately 500 feet long, 12 feet wide, and 4 feet deep, will be replaced each year that it is recruited as bed material through scour and transport of the gravel downstream. As part of their monitoring, Golder Associates surveyed two detailed cross sections of the berm and four channel cross sections at and downstream of the berm. A fifth channel cross section immediately upstream of the berm is serving as a control. USACF MAR RIVER GRAVEL Draft Phase 1 Methods and Data Report 04115t02e B-1 Cedar River Grave! Study Only the two detailed berm cross sections were repeated in 2000 and 2001, indicating only minor modification and recruitment associated with the smaller runoff events of winter 2001. The five channel cross sections were surveyed immediately prior to this study; three of the five cross sections are very near to existing King County flood study cross sections. uSACE/CEDAR RIVER GRAVEL Draft Phase I Methods and Data Report 04/I5/02e B-2 Cedar River Gravel Study Appendix C Field Data Summaries for Individual Survey Sites Appendix C Field Data Summaries for Individual Survev Sites Attached are data summaries for the 35 cross section and pebble count sites surveyed as part of the Cedar River gravel study. Data for each of these sites include one page of summary statistics; three pages of cross section, longitudinal profile, and bed material distribution graphs; and one page of photocopied field notes showing a sketch of the survey site. Please note that pebble count statistics summarized on the first page of each site summary, and the same statistics incorporated in the bed material figures, are estimates automated during data entry. Values for d84, d50, and d16 sediment sizes shown are calculated by linearly interpolating between adjacent values and then selecting the midpoint of that size class. These values were not updated with the values correctly measured by manually interpreting plotted cumulative size distributions for each site. The plotted data in these summary sheets are correct, as are the data presented in the text and tables of the report. In addition to data summaries for the 35 survey sites, one -page sediment summaries for each of the tributaries and sampled bed features are also included. All summary sheets are provided in order by river mile, from upstream (above Landsburg dam) to downstream (at Lake Washington). USAC&CEDAR RIVER GRAVEL Draft Phase I Methods and Data Report 04/1902e C-1 Cedar River Grave! Study Cedar River Gravel Study Data Summary for Site No.1, Cross Section No. New5, Located in Segment 1 at River Mile 23.580 Segment Summary Segment 1 is 0.485 miles long, extending from RM 23.665 to RM 23.180. It is generally described as: Upstream of Landsburg pool. Average gradient is estimated to be tbd. Known local sediment sources are: Old slump scar at RM 23.3. Data collected during this study include: Sites 1-2; additional point count u/s Site 2; subsurface sample u/s Site 3. Other studies active in this segment include: None. Subsegment Summary Description: Natural, unconfined, no backwater effects from Landsburg dam; located 207' d/s of d/s girder on old RR bridge NE of (1st crossing u/s of) Landsburg Widths and Depths Surveyed Width (ft) 374.0 BF Width ft 137.7 BF Depth ft 2.92 Width/Depth Ratio (ft/ft) 47.1 Bed Width ft 129.4 Active Width (ft) 129.4 Active Depth (ft) 1.03 Confinement and Banks 10 yr Width ft nd 10 yr/BF Ratio 0.00 BF Elevation ft, datum 557.3 10 yr Elevation ft, datum nd LB RB Est. % Levee 0 0 Est. % Revetment 0 0 Bank Ht., Typical ft 2 4 Bank Ht., Max (ft) 4 6 Material Source Alluvium nd G.O.? Dom/Subdom Size Sa/Gr Gr/Bldr Bank Size Relative to Bed 25-75% < as. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types None Gross Spawn Area sq. ft. 36400 Percent Usable 80 ASA sq.ft. 29120 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment None Fish Observed, adj. Segment Gradients Survey Length (ft) 280.0 Water Surface Slope ft/ft 0.0015 Avg Bed Slope (ft/ft) -0.0027 L25 Bed Slope (ft/ft) -0.0011 M50 Bed Slope (ft/ft) -0.0026 R75 Bed Slope ft/ft -0.0044 Geomorphology Bed Morphology Plane bed Channel Pattern Single Subsegment Adj. Segment Gravel Bar Type None None Bar Material Typ. Bar Width (ft) Max. Bar Width ft Max. Bar Width cw Bar Vegetation Fine Sediment In Riffles Local, sheltered locations In Pools N/A Cobble Embeddedness <15% Notes, Comments Q = 293 at Landsburg Above Div. Datum: NAVD88 _ Bankfull Confidence: Mod Bankfull Indicators: Slope breaks; alder root below RBF; LB has old side channel ASA Deductions: Fine sediment in margins; Ig substrate and high velocity at u/s end Pebble Counts ID A B C D Method Count Visual None None Cross Section Location 311 to 198 322 to 311 0 to 0 0 to 0 Sizes (mm) Maximum mobile nd nd nd nd Maximum 113 25 nd nd d84 57 4 _ 1 nd nd d50 29 2 nd -nd d16 14.5 1 nd nd Minimum 0.10 0.10 nd nd Seg 1 Site 1.123 02/06/02 Segment 1, Site No.1 Cross Section No. News, at River Mile 23.580 Channel Cross Section Bankfull Width = 137.7 ft.; Bankfull Depth = 2.92 ft. CO566 RPIN CO j 564 Q z 562 -P E ii FP 560 SC m 558 F 556 B o--------- 554 m w 552 0 100 200 300 400 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 129.4 ft.; Active Width = 129.4 ft.; Active Depth = 1.03 ft. 564 CO o 563 > 562 z 561 560 559 558 557 556 L B ------------------- 0555 'm 554 > C 553 w 552 150 170 190 210 230 250 270 290 310 330 350 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0015 and Avg Bed Gradient =-0.0027 — 556 ro - CO z 555 E m 554 — 0 553 ------ .2 •---- ----- w 552 160 140 120 100 80 60 40 20 0 -20 -40 -60 -80 -100 -120 -140 -160 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) s BedEl L + BedEl M • BedEl R +- WaterSurface Seg 1 Site 1.123 02/05/02 Segment 1, Site No.1 Cross Section No. New5, at River Mile 23.580 Pebble Count Statistics 120 I k 100 F G Max d84 d 16 Min 80 B E N 0 60 '^ 57 a) _ U • d50 40 -7-129 20 0 A, 311 to 198 B, 322 to 311 C, 0 to 0 D, 0 to 0 Pebble Count Pebble Count Statistics (zoom) 60 57 40 Max a) d84 N d16 � a) 29 Min U 20 • d50 0 A, 311 to 198 B, 322 to 311 C, 0 to 0 D, 0 to 0 Pebble Count Seg 1 Site1.123 02/06/02 Segment 1, Site No.1 Cross Section No. NewS, at River Mile 23.580 Pebble Count A 100% 113 90% 80% c 70% m L F' 60% d ii 50% c 2 40% m a- 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% 90% 80% c 70% m L 60% a� c ii 50% c c a`mi 40% ) n' 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% C 70% m L 60% m C ii 50% c v 40% a� a 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Seg 1 Site 1.123 02/05/02 Tally 0 0 0 0 0 0 0 0 0 3 5 31 22 23 10 13 3 2 2 1 4 119 Lateral Gravel Bar Pebble Count Tributary to Mainstem Segment No. 1 at River Mile 23.43 Nearest Downstream Study Site: Segment 1, Site 2 at River Mile 23.305 Particle Size Bedrock VL Boulder; 2049-4096 L Boulders 1025-2048 M Boulders 513-1024 S Boulders 385-512 S Boulders 257-384 L Cobbles 193-256 L Cobbles 129-192 S Cobbles 97-128 S Cobbles 65-96 VC Gravel 49-64 VC Gravel 33-48 C Gravel 25-32 C Gravel 17-24 M Gravel 13-16 M Gravel 9-12 F Gravel 7-8 F Gravel 5-6 VF Gravel 3-4 Sand 1-2 Sa/Si/CI <1 100% 90% 80% c 70% m t 60% C E 50% c v 40% `m 30% 20% 10% 0% Pct Dist Cum Dist 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 2.5% 100% 4.2% 97% 26.1 % 93% 18.5% 67% 19.3% 49% 8.4% 29% 10.9% 21% 2.5% 10% 1.7% 8% 1.7% 6% 0.8% 4% 3.4% 3% E N Un m m o- 130 120 110 100 90 80 70 60 50 40 30 20 10 0 Pebble Count Statistics Max d84 d16 Min • d50 • MaxMob oils Pebble Count Lateral Gravel Bar Pebble Count 1 81 - 29 F 1 10 100 1000 Particle Size (mm) Notes: Additional sample collected by Jones & Stokes & Sue Perkins on 09/20/01 Small gravel bar located about 740 ft u/s of Site 2, and close to equidistant between Sites 1 and 2 (Segment 1) Bar is along RB, approximately 100 ft long and a maximum of 30 ft wide (typical 25 ft wide). Max mobile of 115 mm obtained from u/s portion of bar; survey at middle (emergent) portion of bar, where 70 mm was typical maximum size. Photos: Roll 6 photos 1 and 2 looking d/s Seg1 Lateral Gravel Bar.123 02/06/02 Cedar River Gravel Study Data Summary for Site No.2, Cross Section No. New4, Located in Segment 1 at River Mile 23.305 Segment Summary Segment 1 is 0.485 miles long, extending from RM 23.665 to RM 23.180. It is generally described as: Upstream of Landsburg pool. Average gradient is estimated to be tbd. Known local sediment sources are: Old slump scar at RM 23.3. Data collected during this study include: Sites 1-2; additional point count u/s Site 2; subsurface sample u/s Site 3. Other studies active in this segment include: None. Subsegment Summary Description: Natural, unconfined, no backwater effects from Landsburg dam; 2nd of three XS in Segment 1 Widths and Depths Surveyed Width (ft) 564.0 BF Width (ft) 112.0 BF Depth (ft) 3.80 Width/Depth Ratio (ft/ft) 29.4 Bed Width (ft) 108.0 Active Width (ft) 108.0 Active Depth (ft) 1.53 Confinement and Banks 10 yr Width (ft) ERR 10 yr/BF Ratio ERR BF Elevation (ft, datum) 553.8 10 yr Elevation (ft, datum) nd LB RB Est. % Levee 0 0 Est. % Revetment 0 0 Bank Ht., Typical (ft) 45 ft est <2 Bank Ht, Max (ft) 45 ft est <3 Material Source Alluvium nd Dom/Subdom Size Bldr/Cob Sa Bank Size Relative to Bed 25-75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types Pool Gross Spawn Area (sq. ft.) 24192 Percent Usable 55 ASA (sq. fL) 13305.6 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment One 6" trout Fish Observed, adj. Segment Gradients Survey Length (ft) 224.0 Water Surface Slope (ft/ft 0.0037 Avg Bed Slope (f tft) -0.0012 L25 Bed Slope (ft/ft) 0.0029 M50 Bed Slope (ft/ft) -0.0057 R75 Bed Slope (ft/ft) -0.0008 Geomorphology Bed Morphology Plane bed Channel Pattern Single Subsegment Ad'. Segment Gravel Bar Type None Point Bar Material 30 - 90 mm Gr Typ. Bar Width (ft) 25 Max. Bar Width (ft) 30 Max. Bar Width (cw) 0.3 Bar Vegetation Bare of vegetation Fine Sediment In Riffles Local, sheltered locations In Pools Widespread Cobble Embeddedness <15% Comments Bankfull Indicators: Slope break at RBF with overbank sand deposition; LB = steep slope, indiscemable BF ASA Deductions: Deduct for. LB thalweg and pool depth (40%); fine sediment in RB margin (5 oho) Pebble Counts ID A B C D Method Count Visual Visual None Cross Section Location 121 to 55 55 to 37 37 to 13 0 to 0 Sizes (mm) _ Maximum mobile 186 nd nd nd Maximum 161 762 449 nd d84 81 500 321 nd d50 41 381 3 nd d16 10.5 190.0 1.5 nd Minimum 1.50 4.00 0.10 nd Seg1 Site2.123 02/06/02 Segment 1, Site No.2 Cross Section No. New4, at River Mile 23.305 Channel Cross Section Bankfull Width = 112.0 ft.; Bankfull Depth = 3.80 ft. 578 0 Q 574 z 570 E 566 0 562 w k IN 558 0 554 f m — a> 550 w 546 0 100 200 300 400 500 600 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 108.0 ft.; Active Width = 108.0 ft.; Active Depth = 1.53 ft. 558 CO cO 557 Q 556 Z 555 t3 � 554 L 0 553 C,552 w -------------------------f 551 c PC 550 0 = 549 Q) 548 w 547 0 10 20 30 40 50 60 70 80 90 100 110 120 130 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0037 and Avg Bed Gradient =-0.0012 553 CO Q 552 z E 551 m -- a� 550 a- — — — — — — — — — — — — — — — — — — — — — - :4 — — — C F - - -_ - �- - - _ _ 549 _ _ _ CU w 548 130 110 90 70 50 30 10 -10 -30 -50 -70 -90 -110 -130 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) ■ BedEl L + BedEt M - BedEl R — WaterSurface Seg 1 Site2.123 02/05/02 Segment 1, Site No.2 Cross Section No. New4, at River Mile 23.305 Pebble Count Statistics 800 600 E N in Max d84 d16 Min 0 400 • d50 • MaxMob 381 321 200 0186 81 1 0 A, 121 to 55 B, 55 to 37 C, 37 to 13 D, 0 to 0 Pebble Count 500 400 E E N 300 cn ro m 200 o_ 100 0 Pebble Count Statistics (zoom) ' 0 i 381 321 •186 81 r41 r A, 121 to 55 B, 55 to 37 C, 37 to 13 D, 0 to 0 Pebble Count I Max d84 d16 Min • d50 • MaxMob Seg 1 Site2.123 02/05/02 Segment 1, Site No.2 Cross Section No. New4, at River Mile 23.305 Pebble Count A 100% 16 90% 80% c 70% co 444 60% ii 50% c v 40% 2 d 30% 00, 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% 90% 80% c 70% m r 60% a� ii 50% c $ 40% `m n 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% c 70% ca t 60% 0) c ii 50% C I u 40% N � d 30% 20% 10% l- i 0% 1 10 100 1000 Particle Size (mm) Seg1 Site2.123 02/05/02 Tally 0 0 0 0 0 0 0 2 11 36 24 19 5 4 1 1 0 0 0 0 0 103 Bar Surface Material Pebble Count On Mainstem Segment No. 1 at River Mile 23.21 Nearest Downstream Study Site: Segment 2, Site 3 at River Mile 23.155 Particle Size Bedrock VL Boulder: 2049-4096 L Boulders 1025-2048 M Boulders 513-1024 S Boulders 385-512 S Boulders 257-384 L Cobbles 193-256 L Cobbles 129-192 S Cobbles 97-128 S Cobbles 65-96 VC Gravel 49-64 VC Gravel 33-48 C Gravel 25-32 C Gravel 17-24 M Gravel 13-16 M Gravel 9-12 F Gravel 7-8 F Gravel 5-6 VF Gravel 3-4 Sand 1-2 Sa/Si/CI <1 Pct Dist Cum Dist 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 1.9% 100% 10.7% 98% 35.0% 87% 23.3% 52% 18.4% 29% 4.9% 11% 3.9% 6% 1.0% 2% 1.0% 1 % 0.0% 0% 0.0% 0% 0.0% 0% 0.0% 0% 0.0% 0% 220 200 180 E 160 140 120 100 m 80 o_ 60 40 20 0 Pebble Count Statistics Max d84 d16 Min • d50 MaxMob 00 8 Il 81 A B Pebble Count Bar Surface Material Pebble Count 100% 161 90% 1 80% B_ c 70% cU A 60% ii 50% E S7 I k 2 40% 30% 20% 10% r C 0% 1 10 100 1000 Particle Size (mm) Notes: Surface "skin" over subsurface bulk sample collected by Jones & Stokes & Sue Perkins on 09/20/01 Surface/subsurface sample (shown as "A") collected approx 1/4 of total bar length down from u/s tip of bar. Additional point count taken 1/3 of bar distance up from the d/s tip of bar on 09/18/01 is also displayed in the figures as "B" (no raw data is shown). This bar is located just u/s of the break between Segments 1 and 2, which marks the u/s limit of the Landsburg reservoir. Segl Bar Surface Material.123 02/06/02 Cedar River Gravel Study Data Summary for Site No.3, Cross Section No. New3, Located in Segment 2 at River Mile 23.155 Segment Summary Segment 2 is 0.470 miles long, extending from RM 23.180 to RM 22.710. It is generally described as: Landsburg pool. Average gradient is estimated to be tbd. Known local sediment sources are: None observed. Data collected during this study include: Sites 3-5. Other studies active in this segment include: Interfluve samples. Subsegment Summary Description: Immediately d/s of segment break w/ Segment 1 (u/s limit of Landsburg pool —originally assumed to be in Segment 1) Widths and Denths Surveyed Width (ft) 797.0 BF Width (ft) 83.0 BF Depth (ft) 4.02 Width/Depth Ratio (ft/ft) 20.6 Bed Width (ft) 81.0 Active Width (ft) 81.0 Active Depth (ft) 2.55 Confinement and Banks 10 yr Width (ft) ERR 10 yr/BF Ratio ERR BF Elevation (ft, datum) 550.9 10 yr Elevation (ft, datum) nd LB RB Est. % Levee 0 100 Est. % Revetment 0 0 Bank Ht., Typical (ft) 2.5 10 Bank Ht., Max (ft) 4 12 Material Source Alluvium Riprap on G. Dom/Subdom Size Sa/Gr Bldr Bank Size Relative to Bed 25-75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Glide Secondary Habitat Types None Gross Spawn Area (sq. ft.) 13446 Percent Usable 5 ASA (sq. ft.) 672.3 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment 2 small trout @ 2" - 6" Fish Observed, adj. Segment Gradients Survey Length (ft) 166.0 Water Surface Slope (ft/ft: nd Avg Bed Slope (ftt t) nd L25 Bed Slope (ft/ft) nd M50 Bed Slope (ft/ft) nd R75 Bed Slope (ft(ft) nd Geomorvholoov Bed Morphology Plane bed Channel Pattern Single Subsegment I Adj. Segment Gravel Bar Type None Point Bar Material C.Gr/S.Cob. Typ. Bar Width (ft) 30 Max. Bar Width (ft) 55 Max. Bar Width (cw) 0.7 Bar Vegetation Bare of vegetation Fine Sediment In Riffles Over most of bed In Pools Widespread Cobble Embeddedness >35% Notes, Comments Additional pebble count and subsurface sample on bar in Segment 1 located just u/s of this site in Segment 2; no longitudinal profile surveyed Max Mobile size for PebCount A is from gravel bar u/s Q = 292 at Landsburg Above Div. Datum: NAVD88 Bankfull Indicators: Slope break to floodplain on LB: narrow bench w/ slope break before RR fill on RB Pehhle Cnunts low velocity ID A B C D Method Visual Visual None None Cross Section Location 681 to 739 739 to 762 0 to 0 0 to 0 Sizes (mm) Maximum mobile 210 nd nd nd Maximum 81 1537 nd nd d84 29 225 nd nd d50 6 41 nd nd d16 1.5 5.5 nd nd Minimum 0.10 0.10 nd nd Seg2Site3.123 02/06/02 Segment 2, Site No.3 Cross Section No. New3, at River Mile 23.155 Channel Cross Section Bankfull Width = 83.0 ft.; Bankfull Depth = 4.02 ft. 568 CcO 0 564 z 560 p 556 PP LPIN v 552 F—R 548 0 CU > 544 m w 540 0 100 200 300 400 500 600 700 800 900 Distance from LB to RB (feet) — Elev — WaterSurface 555 Cross Section with Pebble Count Boundaries Streambed Width = 81.0 ft.; Active Width = 81.0 ft.; Active Depth = 2.55 ft. - 00 553 j z 551 BF R BV E 549 ca o_ ------------------- 547 m 545 0 PC T 543 m w 541 650 660 670 680 690 700 710 720 730 740 750 760 770 Distance from LB to RB (feet) — Elev — WaterSurface 1 Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations No Profile Surveyed for this Site OD 0 Q z E m O m w c 0 M m w 0 0 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) 9 BedEl L+ BedEl M k BedEl R 'k Data D Seg2Site3.123 02/06/02 Segment 2, Site No.3 Cross Section No. New3, at River Mile 23.155 Pebble Count Statistics 1600 1400 1200 Max 1000 d84 N d16 ) 800 Min • d50 600 �- a - MaxMob 400 200 10 0 9 41 A, 681 to 739 B, 739 to 762 C, 0 to 0 D, 0 to 0 Pebble Count 400 cN am N in 200 m U ns o_ 100 M Pebble Count Statistics (zoom) 010 A, 681 to 739 B, 739 to 762 C, 0 to 0 Pebble Count D,0to0 Max d84 d16 Min • d50 - -0— MaxMob Seg2Site3.123 02/06/02 Segment 2, Site No.3 Cross Section No. New3, at River Mile 23.155 Pebble Count A 100% 90% 80% c 70% L 60% N u_ 50% C v 40% 2 a 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% 90% 80% — c 70% M L 60% N i 50% c 40% d 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% c 70% L 60% N C i 50% C 40% N a 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Seg2Site3.123 02;06,02 RM 23.155, Segment 2, Site 3 Cedar River Gravel Study Data Summary for Site No.4, Cross Section No. NEW2, Located in Segment 2 at River Mile 22.945 Segment Summary Segment 2 is 0.470 miles long, extending from RM 23.180 to RM 22.710. It is generally described as: Landsburg pool. Average gradient is estimated to be tbd. Known local sediment sources are: None observed. Data collected during this study include: Sites 3-5. Other studies active in this segment include: Interfluve samples. Subsegment Summary Description: Approx 2000 ft u/s of dam in Landsburg pool; at u/s end of straight channel reach before beginning meanders; primarily for xs—no sediment data and no profile data collected Widths and Depths Surveyed Width (ft) _ BF Width (ft) 220.0 105.0 BF Depth (ft) 6.95 Width/Depth Ratio (fVft) 15.1 Bed Width (ft) 97.0 Active Width (ft) 102.0 Active Depth (ft) 4.66 Confinement and Banks 10 yr Width (ft) ERR 10 yr/BF Ratio ERR BF Elevation (ft, datum) 549.6 10 yr Elevation (ft, datum) nd LB RB Est. % Levee 0 0 Est. % Revetment 0 0 Bank Ht., Typical (ft) 6 <2 Bank Ht., Max (ft) 8 <2 Material Source G.O. Alluvial Dom/Subdom Size Bldr/Cob Fines Bank Size Relative to Bed 25-75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Glide Secondary Habitat Types Pool Gross Spawn Area (sq. ft.) 20564 Percent Usable 0 ASA (sq. ft.) 0 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment 3 small trout Fish Observed, adj. Segment Gradients Survey Length (ft) 210.0 Water Surface Slope (ft/ft nd Avg Bed Slope (ft/ft) nd L25 Bed Slope (ft/ft) nd M50 Bed Slope (ft/ft) nd R75 Bed Slope (ft/ft) nd Geomorphology Bed Morphology Regime Channel Pattern Single Subsegment I Adj. Segment Gravel Bar Type None None Bar Material Typ. Bar Width (ft) Max. Bar Width (ft) Max. Bar Width (cw) Bar Vegetation Fine Sediment In Riffles N/A In Pools Widespread Cobble Embeddedness >35% Notes, Comments No longitudinal survey or pebble count Q = 292 at Landsburg Above Div. Datum: NAVD88 Bankfull Confidence: Low Bankfull Indicators: vertical bank on LB; sharp slope break on RB, but highly regulated flows ASA Deductions: substrate covered by fine deposition in Landsburg pool Pebble Counts ID A B C D Method Visual None None None Cross Section Location 123 to 220 0 to 0 0 to 0 0 to 0 Sizes (mm) Maximum mobile nd nd nd nd Maximum 769 nd nd nd d84 nd nd nd nd d50 0.10 nd nd nd d16 nd nd nd nd Minimum 0.10 nd nd nd Seg2Site4.123 02/06/02 Segment 2, Site No.4 Cross Section No. NEW2, at River Mile 22.945 Channel Cross Section Bankfull Width = 105.0 ft.; Bankfull Depth = 6.95 ft. PIN o°Do 553 0 Q 551 z MY B E 549 ------- ----- C 547 a� 545 a� c 543 0 > B 541 d w 539 0 20 40 60 80 100 120 140 160 180 200 220 240 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 97.0 ft.; Active Width = 102.0 ft.; Active Depth = 4.66 ft. 552 co 551 > R 550 IF z9-------------------------- — — E 548 547 SO 546 545 w 544 543 0 542 > 541 m T 540 w 539 0 10 20 30 40 50 60 70 80 90 100 110 120 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Surveyed for this Site 1 CO 0 z E 0 a� w C 0 m w 0 0 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) f BedEl L + BedEl M -A- BedEl R -A' Data D Seg2Site4.123 02/06/02 Segment 2, Site No.4 Cross Section No. NEW2, at River Mile 22.945 Pebble Count Statistics 800 600 E Max d84 N d16 �n ID 400 Min U m • d50 a 200 0 10.10 A, 123 to 220 B, 0 to 0 C, 0 to 0 D, 0 to 0 Pebble Count Pebble Count Statistics (zoom) 10 8 E Max 6 (Dd84 d16 inN Min - �, 4 coo • d50 a 2 0 C 0.10 A, 123 to 220 B, 0 to 0 C, 0 to 0 D, 0 to 0 Pebble Count Seg2Site4.123 02/06/02 Segment 2, Site No.4 Cross Section No. NEW2, at River Mile 22.945 Pebble Count A 100% 90% 80% c 70% m L 60% N ii 50% c v 40% m 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count 6 100% 90% 80% M 70% L ~ 60% N C ii 50% a 40% U a_ 30% 20% 10% 0% 1 10 100 Particle Size (mm) Seg2Site4.123 02;05,02 7T Cedar River Gravel Study Data Summary for Site No.S, Cross Section No. NEW1, Located in Segment 2 at River Mile 22.760 Segment Summary Segment 2 is 0.470 miles long, extending from RM 23.180 to RM 22.710. It is generally described as: Landsburg pool. Average gradient is estimated to be tbd. Known local sediment sources are: None observed. Data collected during this study include: Sites 3-5. Other studies active in this segment include: Interfluve samples. Subsegment Summary Description: First XS u/s of dam; xs data obtained from bathymetric survey Widths and Denths Surveyed Width (ft) 258.8 BF Width (ft) nd BF Depth (ft) nd Width/Depth Ratio (ft/ft) nd Bed Width (ft) nd Active Width (ft) nd Active Depth (ft) nd Confinement and Banks 10 yr Width (ft) ERR 10 yr/BF Ratio ERR BF Elevation (ft, datum) 546.1 10 yr Elevation (ft, datum) nd LB RB Est. % Levee 0 0 Est. % Revetment 0 ?forebay? Bank Ht, Typical (ft) nd nd Bank Ht., Max (ft) nd nd Material Source nd nd Dom/Subdom Size nd nd Bank Size Relative to Bed 25-75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Pool Secondary Habitat Types Gross Spawn Area (sq. ft.) Percent Usable 0 ASA (sq. ft.) 0 R2 Habitat Type Other Fish Field Fish Observed, in nd Subsegment Fish Observed, adj. Segment Gradients Survey Length (ft) N/A Water Surface Slope (fttft nd Avg Bed Slope (ft/ft) nd L25 Bed Slope (ftt t) nd M50 Bed Slope (ft/ft) nd R75 Bed Slope (ft/ft) nd Geomoroholoav Bed Morphology Regime Channel Pattern Single Subsegment Adj. Segment Gravel Bar Type None None Bar Material Typ. Bar Width (ft) Max. Bar Width (ft) Max, Bar Width (cw) Bar Vegetation Fine Sediment In Riffles N/A In Pools Widespread Cobble Embeddedness >35% = at Pehhle Counts Notes, Comments Low observed ID A B C D Method None None None None Cross Section Location 0 to 0 0 to 0 0 to 0 0 to 0 Sizes (mm) Maximum mobile nd nd nd nd Maximum nd nd nd nd d84 nd nd nd nd d50 nd nd nd nd d16 nd nd nd nd Minimum nd nd nd _ nd Seg2Site5.123 02/06/02 Segment 2, Site No.5 Cross Section No. NEW1, at River Mile 22.760 Channel Cross Section From Bathymetric Survey CO 555 RSLOPE a553 LSLOPE z 551 E m 549 0 547 w 545 0 543 _m w 541 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 Distance from LB to RB (feet) — Elev Cross Section with Pebble Count Boundaries No Pebble Count at This Site 555 553 z 551 E m 549 0 m 547 ? 545 0 543 a� w 541 0 Distance from LB to RB (feet) — Elev Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations No Profile Surveyed 1 0000 0 z E m 0 w c 0 m w 0 0 Distance Relative to Cross Section (0) from U/S (+) to D/S () (feet) f BedEl L + BedEl M -& BedEl R i- Data D Seg2Site5.123 02/06/02 Segment 2, Site No.5 Cross Section No. NEW1, at River Mile 22.760 Pebble Count Statistics No Pebble Counts at This Site E E a) Max N d84 U) d16 a) Min a3 n. 0 A,0to0 B4Oto0 C,0to0 D,0to0 Pebble Count Pebble Count Statistics (zoom) No Pebble Count at This Site E Max N d84 Cn d16 Min as o_ 0 - - A,0to0 B4Oto0 C,0to0 D,0to0 Pebble Count Seg2Site5.123 02/06i02 Segment 2, Site No.5 Cross Section No. NEW1, at River Mile 22.760 Pebble Count A 100% 90% 80% _ c 70% m L 60% N C iz 50% c 2 40% m a 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count 6 100% 90% 80% m 70% r ~ 60% c ii 50% aa) 40% U no 30% 20% 10% — — 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% m 70% L ~ 60% Q7 C ii 50% aci 40% 2 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Seg2Site5.123 02/06; 02 RNI 22.760, Segment 2, Site 5 No Sketch Cedar River Gravel Study Data Summary for Site No.6, Cross Section No. 106, Located in Segment 4 at River Mile 21.610 Segment Summary Segment 4 is 1.150 miles long, extending from RM 22.150 to RM 21.000. It is generally described as: Steep, tightly confined. Average gradient is estimated to be 0.70. Known local sediment sources are: Gravel mitigation site at Rm 22.0; 100 ft high gravel cliff at RM 21.1. Data collected during this study include: Sites 6-7. Other studies active in this segment include: Golder gravel augmentation. Subsegment Summary Description: Flood study cross-section 106, per flood study survey notes. Widths and Depths Gradients Surveyed Width (ft) 92.7 Survey Length (ft) 176.0 BF Width (ft) 87.9 Water Surface Slope (fttk 0.0031 BF Depth (ft) 4.02 Avg Bed Slope (fVft) 0.0046 W idth/Depth Ratio (ft/ft) 21.9 L25 Bed Slope (ft/ft) 0.0061 Bed Width (ft) 63.4 M50 Bed Slope (ft/ft) 60051 Active Width (ft) 72.3 R75 Bed Slope (fUft) 0.0028 Active Depth (ft) 0.71 Geomorpholol Confinement and Banks I Bed Moroholoov Plane bed 10 yr Width (ft) 100.0 10 yr/BF Ratio 1.14 BF Elevation (ft, datum) 98.8 10 yr Elevation ft, datum) 509.82 LB RB Est. % Levee 0 0 Est. % Revetment 0 0 Bank Ht., Typical (ft) 12 12 Bank Ht., Max (ft) 14 14 Material Source G.O. G.O. Dom/Subdom Size Bldr/L.Cob Bldr/L.Cob Bank Size Relative to Bed 25-75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types None Gross Spawn Area (sq. ft.) 11158 Percent Usable 0 ASA (sq. ft.) 0 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment 1 salmonid, 2 1/2" 5-10 trout, 4-8" Fish Observed, adj. Segment Gravel Bar Type None None Bar Material Max. Bar Width (ft) Max. Bar Width (cw) Bar Vegetation Fine Sediment In Riffles Local, sheltered locations In Pools Local, obstruct, slack Cobble Embeddedness <15% Pebble Counts Notes, Comments ID A B C D Method Count None None None Cross Section Location 92 to 28 0 to 0 0 to 0 0 to 0 Sizes (mm) Maximum mobile nd nd nd nd Maximum 769 _ nd nd nd d84 321 _ nd nd nd d50 57 nd nd nd d16 5.5 nd nd nd Minimum 0.10 nd nd nd Seg4Site6.123 02/06/02 Segment 4, Site No.6 Cross Section No. 106, at River Mile 21.610 Channel Cross Section Bankfull Width = 87.9 ft.; Bankfull Depth = 4.02 ft. 101 m 100 DNA 99 98 m 97 R aa) 96 0 95 B m T a)94 w 93 0 10 20 30 40 50 60 70 80 90 100 110 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section With Pebble Count Boundaries Streambed Width = 63.4 ft.; Active Width = 72.3 ft.; Active Depth = 0.71 ft. 101 a� 100 d 99 m 98 97 P aa) 96 0 95 C 94 T w 93 0 10 20 30 40 50 60 70 80 90 100 110 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0031 and Avg Bed Gradient = 0.0046 97 a) m of 96 - E m 95 — — — — — — — — — — — — tg %----_-_-___ = 0 94 - w — —f 93 100 50 0 -50 -100 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) f BedEl L � BedEl M � BedEl R i- WaterSurface Seg4Site6.123 02/06/02 Segment 4, Site No.6 Cross Section No. 106, at River Mile 21.610 800 750 700 650 600 550 E 500 N 450 �n 400 350 300 250 200 150 100 50 0 Pebble Count Statistics Max d84 d16 Min • d50 321 A,92to28 B4Oto0 C,0to0 D,0to0 Pebble Count Pebble Count Statistics (zoom) 400 360 320 2-1 280 E Max 240 d84 N d16 in 200 Min a) iE 160 M • d50 a 120 80 40 0 A,92to28 B4Oto0 C,0to0 D,0to0 Pebble Count Seg4Site6.123 02/06/02 Segment 4, Site No.6 Cross Section No. 106, at River Mile 21.610 Pebble Count A 100% 90% 80% c 70% m t 60% `m it 50% c u 40% 2 a 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% 90% 80% c 70% CO r 60% d c E 50% c 2 40% m 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% c 70% m L 60% a`) u_ 50% c v 40% 2 a 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Seg4Site6.123 02/06/02 RM 21.610, Segment 4, Site 6 n Cedar River Gravel Study Data Summary for Site No.7, Cross Section No. 101m, Located in Segment 4 at River Mile 21.261 Segment Summary Segment 4 is 1.150 miles long, extending from RM 22.150 to RM 21.000. It is generally described as: Steep, tightly confined. Average gradient is estimated to be 0.70. Known local sediment sources are: Gravel mitigation site at Rm 22.0; 100 ft high gravel cliff at RM 21.1. Data collected during this study include: Sites 6-7. Other studies active in this segment include: Golder gravel augmentation. Subsegment Summary Description:-30-50' U/S of probable flood study cross-section 101, per flood study survey notes. Immediately d/s of USGS gage # 12117600 below Landsburg Widths and BF Width (ft) 92.1 Ratio (ft/ft) 24.0 83.4 Active Width 0.72 Confinement and Banks 10 yr Width ft 100.0 10 yr/BF Ratio 1.09 BF Elevation (ft, datum) 99.6 10 yr Elevation ft, datum 496.79 LB RB Est. % Levee 0 0 Est. % Revetment 0 0 Bank Ht., Typical ft 8 8 Bank Ht., Max (ft) 12 12 Material Source G.O. G.O. Dom/Subdom Size Cob/Gr Cob/Gr Bank Size Relative to Bed >75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Rifle Secondary Habitat Types Glide Gross Spawn Areas . ft 16928 Percent Usable 50 ASA .ft. 8464 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment 4 Small trout, 2-4" Fish Observed, adj. Segment Gradients Survey Length (ft) 184.0 Water Surface Slope ft/ft 0.0023 Avg Bed Slope ft/ft) -0.0041 L25 Bed Slope (ft/ft) 0.0047 M50 Bed Slope (ft/ft) -0.0164 R75 Bed Slope ft/ft) -0.0192 Geomoroholoov Bed Morphology Plane bed Channel Pattern Single Subsegment I Adj. Segment Gravel Bar Type None Lateral Bar Material Bldr Typ. Bar Width (ft) Max. Bar Width ft Max. Bar Width (cw) Bar Vegetation Fine Sediment In Riffles Local, sheltered locations In Pools Patches + local Cobble Embeddedness 15-35% Notes_ Comments Q = 103 at Landsburg Below Div. Datum: Relative Bankfull Confidence: Mod Bankfull Indicators: nd ASA Deductions: Fines, Boulders, Chute = -50% of total area Pebble Counts ID A B C D Method Count None None None Cross Section Location 106 to 23 0 to 0 0 to 0 0 to 0 Sizes (mm Maximum mobile nd nd nd nd Maximum 449 nd nd nd d84 161 nd nd nd d50 41 nd nd nd d16 10.5 nd nd nd Minimum 0.10 nd nd nd Seg4Site7.123 02/06/02 Segment 4, Site No.7 Cross Section No. 101m, at River Mile 21.261 Channel Cross Section Bankfull Width = 92.1 ft.; Bankfull Depth = 3.83 ft. 108 m m 106 a� 104 E m 102 IN R 100DF 0 c 98 o_ 1i— — — — — — — — — — — — — — — — — — > 96 m w 77 94 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 83.4 ft.; Active Width = 83.4 ft.; Active Depth = 0.72 ft. a� 108 m m 106 w E 104 m 0 102 R 100 c o 98 v r. — — — — — — — — — — — — — — — — — — > 0 96 w 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0023 and Avg Bed Gradient =-0.0041 97 m m 96 ' E 95 Z -- ' 94 ' 93 o _ __-----—— — — — — —� ♦—— m > 92 m w 91 100 50 0 -50 -100 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) f BedEl L + BedEl M � BedEl R 'A, WaterSurface Seg4Site7.123 02/06/02 Segment 4, Site No.7 Cross Section No. 101m, at River Mile 21.261 Pebble Count Statistics 500 450 400 350 E Max 300 d84 a) in 250 Min Min � C 200 • d50 o_ 150 161 r 100 F r 50 r 0 A,106to23 B4Oto0 C,0to0 D,0to0 Pebble Count Pebble Count Statistics (zoom) 240 220 200 _ 180 E 160 fr Max E d84 N 140 d16 u) 120 Min a� LE 100 m • d50 80 60 40 1 20 0 A,106to23 B4Oto0 C,0to0 D,0to0 Pebble Count Seg4Site7.123 02/06/02 Segment 4, Site No.7 Cross Section No. 101m, at River Mile 21.261 Pebble Count A 100% 90% 80% c 70% m L 60% 4 a� ii 50% c v 40% 2 a 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% 90% 80% c 70% co t 60% a� ii 50% c u 40% `a d 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% c 70% co r 60% C ii 50% c $ a`40% ) d 30% - 20% 10% 0% 1 10 100 1000 Particle Size (mm) Seg4Site7.123 02/06/02 RM 21.261, Segment 4, Site 7 Cedar River Gravel Study Data Summary for Site No.8, Cross Section No. 9413, Located in Segment 5 at River Mile 20.493 Segment Summary Segment 5 is 1.902 miles long, extending from RM 21.000 to RM 19.098. It is generally described as: Confined w/ sed sources. Average gradient is estimated to be 0.62. Known local sediment sources are: 70-120 ft gravel cliff —major gravel source at RM 20. 75; Walsh Lake Diversion channel at RM 20.4; gravel cliff 15-40 ft high at RM 19.7; 150 ft high steep bank at RM 19.3 has stabilized since 1992. Data collected during this study include: Sites 8-9. Other studies active in this segment include: None. Subsegment Summary Description: Flood study cross-section 94B, per flood study survey notes Widths and Depths Surveyed Width (ft) 106.0 BF Width ft 96.9 BF Depth (ft) 3.49 Width/Depth Ratio (ft(ft) 27.8 Bed Width (ft) 72.9 Active Width ft 72.9 Active Depth ft 0.68 Confinement and Banks 10 yr Width (ft) 130.0 10 yrBF Ratio 1.34 BF Elevation ft, datum) 470.3 10 yr Elevation (ft, datum) 474.13 LB RB Est. % Levee 0 0 Est. % Revetment 0 0 Bank Ht., Typical (ft) 10 2 Bank HL, Max (ft) 15 15 Material Source alluvial alluvial Dom/Subdom Size Cob/Sa Cob/Sa Bank Size Relative to Bed 25-75% < c.s. Bank Erosion Intermittent Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types None Gross Spawn Area sq. ft.) 18800 Percent Usable 80 ASA (sq. ft.) 15040 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment 1 sculpin, 3" Fish Observed, adj. Segment 4 adult sockeye Gradients Survey Length (ft) 194.0 Water Surface Slope ft/ft 0.0035 Avg Bed Slope ft/ft 0.0032 L25 Bed Slope (ft/ft) -0.0017 M50 Bed Slope (ftlft) -0.0020 R75 Bed Slope (ft/ft) 0.0133 Geomorphology Bed Morphology Plane bed Channel Pattern Single Subsegment I Adj. Segment Gravel Bar Type None Lateral Bar Material Bldr T p. Bar Width (ft) Max. Bar Width (ft) Max. Bar Width (cw) Bar Vegetation Fine Sediment In Riffles Local, sheltered locations In Pools Local, obstruct, slack Cobble Embeddedness <15% Notes, Comments "Adj. Segment" gravel bar is on RB upstream of transect Q =103 at Landsburg Below Div. Datum: NAVD88 Bankfull Confidence: nd Bankfull Indicators: nd ASA Deductions: nd Pebble Counts A B - C D Method Count None None None Cross Section Location 94 to 21 0 to 0 1 0 to 0 0 to 0 Sizes (mm Maximum mobile nd nd nd nd Maximum 449 nd nd nd d84 81 nd nd nd d50 41 nd nd nd d16 10.5 nd nd nd Minimum 0.10 nd nd nd Seg5Site8.123 02/06/02 Segment 5, Site No.8 Cross Section No. 9413, at River Mile 20.493 Channel Cross Section Bankfull Width = 96.9 ft.; Bankfull Depth = 3.49 ft. - 472 00 0 471 F Q z RB 470 E io 469 o 468 R 467 0 > 466 0 w 465 0 10 20 30 40 50 60 70 80 90 100 110 120 130 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 72.9 ft.; Active Width = 72.9 ft.; Active Depth = 0.68 ft. 472 CO j 471 RB z 470 E 469 0 468 wE----------------- � 467 0 466 T a� w 465 0 10 20 30 40 50 60 70 80 90 100 110 120 130 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0035 and Avg Bed Gradient = 0.0032 469 CO CO 0 Q 468 z — — — — — — — — ■ — — — — — — — — — — — — -_— — — — — - w466 •---------- _— _-- 465 _d w 464 110 90 70 50 30 10 -10 -30 -50 -70 -90 -110 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) ■ BedEl L � BedEl M i- BedEl R -t WaterSurface Seg5Site8.123 02/06/02 Segment 5, Site No.8 Cross Section No. 9413, at River Mile 20.493 Pebble Count Statistics 480 440 400 360 320 Max 280 d84 in 240 Min m Min .6 200 d 160 • d50 120 80 81 40 0 A,94to21 B4Oto0 C,0to0 D,0to0 Pebble Count Pebble Count Statistics (zoom) 120 100 E 80 Max d84 N d16 (n a� 60 Min U m • d50 a 40 AA 1 20 0 A,94to21 B4Oto0 C,0to0 D,0to0 Pebble Count Seg5Site8.123 02/06/02 Segment 5, Site No.8 Cross Section No. 946, at River Mile 20.493 Pebble Count A 100% 90% 80% c 70% m L 60% U) LZ 50% C u 40% a� d 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% 90% 80% c 70% m L 60% N 50% C c2i 40% N a 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% c 70% m L 60% C c ti 50% C 2 40% N d 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Seg5Site8 123 02/06/02 RNI 20.493, Segment 5, Site 8 31 3, :- V3 Cedar River Gravel Study Data Summary for Site No.9, Cross Section No. 88, Located in Segment 5 at River Mile 19.865 Segment Summary Segment 5 is 1.902 miles long, extending from RM 21.000 to RM 19.098. It is generally described as: Confined w/ sed sources. Average gradient is estimated to be 0.62. Known local sediment sources are: 70-120 ft gravel Giff—major gravel source at RM 20. 75; Walsh Lake Diversion channel at RM 20.4; gravel cliff 15-40 ft high at RM 19.7; 150 ft high steep bank at RM 19.3 has stabilized since 1992. Data collected during this study include: Sites 8-9. Other studies active in this segment include: None. Subsegment Summary Description: Flood study cross-section 88, per King Co flood study notes Widths and Depths Surveyed Width (ft) 109.5 BF Width ft 103.6 BF Depth (ft) 2.24 Width/Depth Ratio (ft/ft) 46.3 Bed Width ft 96.9 Active Width (ft) 96.9 Active Depth ft 0.65 Confinement and Banks 10 Width (ft) 110.0 10 yrBF Ratio 1.06 BF Elevation ft, datum 450.8 10 yr Elevation ft, datum 452.72 LB RB Est. % Levee 0 0 Est. % Revetment 0 6- Bank Ht., Typical ft 4 6 Bank Ht., Max (ft) 8 8 Material Source G.O. G.O. Dom/Subdom Size Cob/Bldr Cob/Bldr Bank Size Relative to Bed 25-75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types None Gross Spawn Area (sq. ft.) 19982 Percent Usable 0 ASA (sq. ft. 0 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment 2 salmonids, 4-6" Fish Observed, adj. Segment 2 adult sockeye, 18-20" Gradients Survey Length (ft) 206.0 Water Surface Slope ftt t 0.0100 Avg Bed Slope (ft/ft) 0.0104 L25 Bed Slope (ft/ft) 0.0093 M50 Bed Slope ft/ft 0.0119 R75 Bed Slope (ft/ft) 0.0100 Geomorphology Bed Morphology Plane bed Channel Pattern Single Subsegment Adj. Segment Gravel Bar Type None Point Bar Material Typ. Bar Width (ft) Max. Bar Width ft Max. Bar Width (cw) Bar Vegetation Established vegetation Fine Sediment In Riffles Local, sheltered locations In Pools N/A Cobble Embeddedness <15% Pebble Counts Notes, Comments ID A B C D Method Count None None None Cross Section Location 125 to 28 0 to 0 0 to 0 0 to 0 Sizes mm Maximum mobile nd nd nd nd Maximum 769 nd nd nd d84 321 nd nd nd d50 161 nd nd nd d16 40.5 nd nd nd Minimum 5.50 nd nd nd Seg5Site9.123 02/06/02 Segment 5, Site No.9 Cross Section No. 88, at River Mile 19.865 Channel Cross Section Bankfull Width = 103.6 ft.; Bankfull Depth = 2.24 ft. 455 CO 00 0 454 z 453 � 452 F 451 w 450 B ------------ ------------ 0449 > 448 m w 447 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 96.9 ft.; Active Width = 96.9 ft.; Active Depth = 0.65 ft. - 455 CO 0 454 z 453 452 F BF 451 aa'' 450 !; — — — — — — — — — — — — — — — — — — — — — — 0449 > m 448 w 447 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0100 and Avg Bed Gradient = 0.0104 450 CO co z 449 m A_ — 0 448 _— — — 0 447 a) A w 446 120 100 80 60 40 20 0 -20 -40 -60 -80 -100 -120 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) • BedEl L + BedEl M t BedEl R '+- WaterSurface Seg5Site9.123 02/06/02 Segment 5, Site No.9 Cross Section No. 88, at River Mile 19.865 Pebble Count Statistics 800 700 _ 600 E Max a> 500 d84 N d16 m 400 Min U 321 • d50 300 200 100 0 A,125to28 B4Oto0 C,0to0 D,0to0 Pebble Count 400 360 320 280 240 a� N in 200 w iE 160 M CL 120 80 40 0 Pebble Count Statistics (zoom) Max d84 d16 Min • d50 2 16 A,125to28 B4Oto0 C,0to0 D,0to0 Pebble Count Seg5Site9.123 02/06/02 Segment 5, Site No.9 Cross Section No. 88, at River Mile 19.865 Pebble Count A 100% 90% 80% 70% L 161 60% C 650% c 40% iv d 30% 20% 10% 0% �—;44 1 10 Particle Size (mm) Pebble Count B 100% 90% 80% C 70% m L F 60% `m C E 50% C u 40% d) a 30% 20% 10% 0% 1 10 Particle Size (mm) 100 100 1000 1000 Pebble Count C 100% 90% 80% C 70% m L � 60% `m C L 50% C a; 40% N 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Seg5Site9.123 02/06/02 RM 19.865, Segment 5, Site 9 Cedar River Gravel Study Data Summary for Site No.10, Cross Section No. 74, Located in Segment 6 at River Mile 18.546 Segment Summary Segment 6 is 1.098 miles long, extending from RM 19.098 to RM 18.000. It is generally described as: Tight bends w/ sed sources Average gradient is estimated to be 0.73. Known local sediment sources are: 10 ft high gravel bank at RM 18.8; 100+ ft high sm. gravel/sand cliff at RM 18.1; Rock Creek (coarse sed, no observed erosion) at RM 18.5. Data collected during this study include: Sites 10-11; Rock Cr pebble count. Other studies active in this segment include: None. Subsegment Summary Description: Flood study cross-section 74. Widths and Depths Surveyed Width (ft) 118.5 BF Width (ft) 104.2 BF Depth (ft) 3.10 Width/Depth Ratio fVft 33.6 Bed Width (ft) 73.0 Active Width ft 73.0 Active Depth (ft) 0.43 Confinement and Banks 10 yr Width (ft) 105.0 10 yr/BF Ratio 1.01 BF Elevation (ft, datum) 404.1 10 yr Elevation ft, datum 406.57 LB RB Est. % Levee 0 0 Est. % Revetment 0 0 Bank Ht., Typical (ft) 4 4 Bank Ht., Max ft 6 6 Material Source alluvial, G.O. alluvial Dom/Subdom Size Cob/Bldr Cob/Bldr Bank Size Relative to Bed 25-75% < c.s. Bank Erosion Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types None Gross Spawn Area . ft. 21715 Percent Usable 40 ASA (sq. ft.) 8686 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment Fish Observed, adj. Segment None Gradients Survey Length (ft) 208.0 Water Surface Slope (ft/ft 0.0077 Avg Bed Slope ft/ft) 0.0117 L25 Bed Slope (ft/ft) _ 0.0108 M50 Bed Slope (ft/ft) 0.0150 R75 Bed Slope (ft/ft) 0.0092 Geomorphology Bed Morphology Plane bed Channel Pattern Single Subsegment Adj. Segment Gravel Bar Type Point None Bar Material L.Cob/Bldr Typ. Bar Width (ft) 20 Max. Bar Width (ft) 30 Max. Bar Width (cw) 0.3 Bar Vegetation Encroaching vegetation Fine Sediment In Riffles Local, sheltered locations In Pools N/A Cobble Embeddedness <15% Notes, Comments Q = 99 at Landsburg Below Div. Datum: NAVD88 (approx.) (red cap rebar could not be located, used ground at labled lath as reference) Bankfull Confidence: High Bankfull Indicators: Top of bar, Alder rooting. �SA Deductions: nd Pebble Counts ID A B C None D Method Count None None Cross Section Location 32 to 105 0 to o 0 to 0 0 to 0 Sizes mm Maximum mobile 260 nd nd nd Maximum 449 nd nd nd d84 161 nd nd nd d50 81 nd nd nd d16 40.5 nd nd nd Minimum 3.50 nd nd nd Seg6Site10.123 02/06/02 Segment 6, Site No.10 Cross Section No. 74, at River Mile 18.546 Channel Cross Section _ Bankfull Width = 104.2 ft.; Bankfull Depth = 3.10 ft. X C2 408 n 10 407 CO p 406 Z 405 404 m 0 403 w 402 --- —� ----" 0 401 T 400 w 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries _ Streambed Width = 73.0 ft.; Active Width = 73.0 ft.; Active Depth = 0.43 ft. X o`a 408 d :° 407 00 0 406 Z 405 404 m 0 403 402 --- —� C— — — — — — ----- c 401 T 400 w 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations _ Avg Water Surface Slope = 0.0077 and Avg Bed Gradient = 0.0117 X n 403 a m 402 CO 0 Q 401 — — — --� z 400 399 y w Y �- 398 c 0 397 w 120 100 80 60 40 20 0 -20 -40 -60 -80 -100 -120 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) w BedEl L 4 BedEl M t BedEl R-dWaterSurface Seg6Site10.123 02/06/02 Segment 6, Site No.10 Cross Section No. 74, at River Mile 18.546 450 420 390 360 330 E 300 270 CD 11 240 a) 210 E 180 EL 150 120 90 60 30 0 Pebble Count Statistics Max d84 d16 Min • d50 • MaxMob 060 16 1 A,32to105 B4Oto0 C,0to0 D,0to0 Pebble Count Pebble Count Statistics (zoom) 200 2W 180 160 -161 140 Max 120 d84 N d16 in 100 Min a� E 80 64 d50 t° • MaxMob d 60 40 20 0 A,32to105 B4Oto0 C,0to0 D,0to0 Pebble Count Seg6Site10.123 02/06; 02 Segment 6, Site No.10 Cross Section No. 74, at River Mile 18.546 100% 90% 80% c 70% m L 60% EZ iL 50% C c2i 40% N d 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% 90% 80% C 70% m L 60% Ul Lz 50% C 2 40% a 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% C 70% m t 60% iv C iz 50% C C 40% F a 30% C 20% 10% 0% 1 10 100 1000 Particle Size (mm) Seg6Site10.123 02/06/02 G� �.. 00 in a� ara c9 C7 O� �o �.. O t/ ..-�---�.r-- Tally 0 0 0 0 0 0 1 2 8 22 20 22 13 8 0 1 0 2 0 0 1 100 Rock Creek Pebble Count Tributary to Mainstem Segment No. 6 at River Mile 18.517 Nearest Downstream Study Site: Segment 6, Site 11 at River Mile 18.145 Particle Size Bedrock VL Boulder: 2049-4096 L Boulders 1025-2048 M Boulders 513-1024 S Boulders 385-512 S Boulders 257-384 L Cobbles 193-256 L Cobbles 129-192 S Cobbles 97-128 S Cobbles 65-96 VC Gravel 49-64 VC Gravel 33-48 C Gravel 25-32 C Gravel 17-24 M Gravel 13-16 M Gravel 9-12 F Gravel 7-8 F Gravel 5-6 VF Gravel 3-4 Sand 1-2 Sa/Si/CI <1 100% 90% 80% m 70% 60% `m ii 50% ! v 40% a� 30% 20% 10% 0% I Pct Dist Cum Dist 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 1.0% 100% 2.0% 99% 8.0% 97% 22.0% 89% 20.0% 67% 22.0% 47% 13.0% 25% 8.0% 12% 0.0% 4% 1.0% 4% 0.0% 3% 2.0% 3% 0.0% 1 % 0.0% 1 % 1.0% 1 % 10 Pebble Count Statistics 260 240 220 200 180 E E 160 140 i-n a� 120 U : 100 0 80 60 40 20 0 Rock Creek Pebble Count Particle Size (mm) Pebble Count 100 Notes: Additional sample collected by Jones & Stokes on 08/29/01 Rock Creek is -400' downstream of Site No. 10 (Seg. 6). Pebble Count taken-80-100' U/S from confluence with Cedar R. in low gradient riffle. Steeper riffle U/S (not sampled) has more cobbles, including Ig. cobbles. Particles > -150mm have algae on them. Max d84 d16 Min • d50 • MaxMob 1000 SEG6ROCK CREEK.123 02/06/02 Cedar River Gravel Study Data Summary for Site No.11, Cross Section No. 70m, Located in Segment 6 at River Mile 18.145 Segment Summary Segment 6 is 1.098 miles long, extending from RM 19.098 to RM 18.000. It is generally described as: Tight bends w/ sed sources. Average gradient is estimated to be 0.73. Known local sediment sources are: 10 ft high gravel bank at RM 18.8; 100+ ft high sm. gravel/sand cliff at RM 18.1; Rock Creek (coarse sed, no observed erosion) at RM 18.5. Data collected during this study include: Sites 10-11; Rock Cr pebble count. Other studies active in this segment include: None. Subsegment Summary Description: Estimated 105 ft u/s of flood study xs 70 (not found); surveyed 680 ft u/s of xs 69; steep outwash slope on RB Widths and Depths Surveyed Width (ft) 108.2 BF Width (ft) 84.3 BF Depth (ft) 4.16 Width/Depth Ratio (ft/ft) 20.3 Bed Width (ft) 69.3 Active Width (ft) 69.3 Active Depth (ft) 1.08 Confinement and Banks 10 yr Width (ft) 240 10 yrBF Ratio 2.85 BF Elevation (ft, datum) 389.2 10 yr Elevation (ft, datum) 393.03 LB RB Est. % Levee 0 0 Est. % Revetment 0 0 Bank Ht., Typical (ft) 4.5 >50 Bank Ht., Max (ft) nd nd Material Source alluvial outwash Dom/Subdom Size Gr/Cob Gr/Sa Bank Size Relative to Bed >75% < c.s. Bank Erosion Outside bends Fish and Habitat Dominant Habitat Type Glide Secondary Habitat Types None Gross Spawn Area (sq. ft.) 14213 Percent Usable 65 ASA (sq. ft.) 9238.45 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment adult sockeye, 2 redds Fish Observed, adj. Segment Gradients Survey Length (ft) 168.0 Water Surface Slope (ft/ft; 0.0007 Avg Bed Slope (ft/ft) 0.0022 L25 Bed Slope (ft/ft) 0.0105 M50 Bed Slope (ft/ft) 0.0001 R75 Bed Slope (ft/ft) -0.0039 Geomorphology Bed Morphology Plane bed Channel Pattern Single Subsegment I Adj. Segment Gravel Bar Type None Point Bar Material Cob/S.Bldr Typ. Bar Width (ft) 40 Max. Bar Width (ft) Max. Bar Width (cw) Bar Vegetation 60 0.7 Encroaching vegetatio Fine Sediment In Riffles Local, sheltered locations In Pools WA Cobble Embeddedness None Notes, Comments Steep outwash slope on RB is source of sediments with >75% finer than 125 mm (est critical size on bed) Q = 99 at Landsburg Below Div. Datum: NAVD88 Bankfull Confidence: nd [probably mod] Bankfull Indicators: nd [RB slope too steep; LB slope break near elevation of top of bar u/s of xs ASA Deductions: nd Pebble Counts ID A B C D Method Count Visual Visual None Cross Section Location 88 to 54 110 to 88 121 to 110 0 to 0 Sizes (mm) Maximum mobile 125 nd nd nd Maximum 113 256 120 nd d84 57 160.5 41 nd d50 41 112.5 29 nd d16 20.5 80.5 20.5 nd Minimum 7.50 28.5 0.10 nd Seg6Sitel 1.123 02/06/02 Segment 6, Site No.11 Cross Section No. 70m, at River Mile 18.145 Channel Cross Section Bankfull Width = 84.3 ft.; Bankfull Depth = 4.16 ft. 394 0 393 > 392 z 391 E 390 389 388 387 B R 386 a 385 .6 384 a'� 383 w 382 10 20 30 40 50 60 70 80 90 100 110 120 130 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 69.3 ft.; Active Width = 69.3 ft.; Active Depth = 1.08 ft. 394 CO 0 393 > 392 z 391 E 390 1- RVF m 389 0 388 387 386 0 385 P PC m 384 383 w 382 10 20 30 40 50 60 70 80 90 100 110 120 130 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0007 and Avg Bed Gradient = 0.0022 388 COCO j 387-- --_- Z --- -- 386 E --__ — 1 m 385 0 384 m r 383 — — — — — — — — — -- — ----- — — — — — — — 382� a� w 381 100 80 60 40 20 0 -20 -40 -60 -80 -100 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) w BedEl L + BedEl M -k BedEl R -} WaterSurface Seg6Site11.123 02/06/02 Segment 6, Site No.11 Cross Section No. 70m, at River Mile 18.145 Pebble Count Statistics 260 240 220 200 180 Max 160 161 d84 (D d 16 N 0 140 Min a) 120 *125 13 a 100 • d50 • MaxMob 80 60 40 41 —41 20 9 0 A, 88 to 54 B, 110 to 88 C, 121 to 110 D, 0 to 0 Pebble Count Pebble Count Statistics (zoom) 180 160 461 140 120 •125 Max d84 N 100 d16 in Min 73 80 • d50 M 60 57 • MaxMob 40 20 0 A, 88 to 54 B, 110 to 88 C, 121 to 110 D, 0 to 0 Pebble Count Seg6Site11.123 02/06/02 Segment 6, Site No.11 Cross Section No. 70m, at River Mile 18.145 Pebble Count A 100% 113 90% 80% 4 c 70% m L F' 60% `m i 50% C 40% Q1 30% 2 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% 90% - 80% c 70% L 60% N C u. 50% C u 40% N d 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% c 70% m L 60% N C u 50% C u 40% d d 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Seg6S ite 11.123 02/06/02 moon 1' I � I i mom wpm ron cv� Cedar River Gravel Study Data Summary for Site No.12, Cross Section No. 65, Located in Segment 7 at River Mile 17.592 Segment Summary Segment 7 is 1.427 miles long, extending from RM 18.000 to RM 16.573. It is generally described as: Upper Dorre Don, variable confinement. Average gradient is estimated to be 0.48. Known local sediment sources are: Minor (50 ft high clay cliff with sand at RM 17.3). Data collected during this study include: Sites 12-13. Other studies active in this segment include: None. Subsegment Summary Description: Flood study cross-section 65, per King Cc flood study notes. Widths and Deoths Surveyed Width (ft) 87.0 BF Width (ft) 72.2 BF Depth (ft) 3.32 Width/Depth Ratio (ft/ft) 21.7 Bed Width (ft) 68.4 Active Width (ft) 68.4 Active Depth (ft) 0.91 Confinement and Banks 10 yr Width (ft) 200.0 10 /BF Ratio 2.77 BF Elevation (ft, datum) 371.1 10 yr Elevation (ft, datum) 375.89 LB RB Est. % Levee 0 100 Est. % Revetment 0 100 Bank Ht., Typical (ft) 4.3 nd Bank Ht., Max (ft) nd nd Material Source nd nd Dom/Subdom Size Gr/Cob nprap Bank Size Relative to Bed >75% < c.s. Bank Erosion Extensive 1x Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types None Gross Spawn Area (sq. ft.) 10658 Percent Usable 50 ASA (sq. ft.) 5329 R2 Habitat Type Other Fish Field Fish Observed, in None Subsegment Fish Observed, adj. Segment Gradients Survey Length (ft) 146.0 Water Surface Slope (ft/ft 0.0017 Avg Bed Slope (ft/ft) 0.0015 L25 Bed Slope (ft/ft) -0.0013 M50 Bed Slope (ft/ft) 0.0012 R75 Bed Slope (ft/ft) 0.0046 Geomorphology Pool -Riffle Channel Pattern None None Typ. Bar Width Max. Bar Width Max. Bar Width Fine Sediment In Riffles Local, sheltered locations In Pools N/A Cobble Embeddedness <15% Pebble Counts Notes, Comments ID A B C D Method Count None None None Cross Section Location 39 to 89 0 to 0 0 to 0 0 to 0 Sizes (mm) Maximum mobile 270 nd nd nd Maximum 225 nd nd nd d84 161 nd nd nd d50 57 nd nd nd d16 20.5 nd nd nd Minimum 0.10 nd nd nd Seg7Site12.123 02/06/02 Segment 7, Site No.12 Cross Section No. 65, at River Mile 17.592 Channel Cross Section Bankfull Width = 72.2 ft.; Bankfull Depth = 3.32 ft. 377 376 o > 375 z 374 373 372 0 RB 371 370 R— 369 0 368 — — m 367 366 w 365 10 20 30 40 50 60 70 80 90 100 110 120 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 68.4 ft.; Active Width = 68.4 ft.; Active Depth = 0.91 ft. 377 CO 376 > 375 z 374 373 —', 372 RB 371 370 369 --- -- 0 368 Ii 367 PC > 366 w 365 10 20 30 40 50 60 70 80 90 100 110 120 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0017 and Avg Bed Gradient = 0.0015 370 COCO 0 > z 369 m 0 368 > —---— — — — ——� w 367 ' 90 70 50 30 10 -10 -30 -50 -70 -90 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) ■ BedEl L 4- BedEl M A- BedEl R -6- WaterSurface Seg7Site12.123 02/06/02 Segment 7, Site No.12 Cross Section No. 65, at River Mile 17.592 Pebble Count Statistics 280 260 8270 240 220 200 Max E 180 84 N 160 d16 a i 140 Min 120 • d50 IL 100 • MaxMob 80 60 57 40 20 0 A,39to89 B4Oto0 C,0to0 D,0to0 Pebble Count Pebble Count Statistics (zoom) 180 270 160 I6 140 120 Max d84 N 100 d16 in Min CD 80 • d50 a 60 • MaxMob 457 40 20 0 A,39to89 B4Oto0 C,0to0 D,0to0 Pebble Count Seg7Site 12.123 02/06/02 Segment 7, Site No.12 Cross Section No. 65, at River Mile 17.592 Pebble Count A 100% 6 5 90% 111 80% C 70% m L 60% a z 50% c 40% a 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% 90% 80% C 70% m L 60% a� C i 50% C 40% a`) 30% 20% 10% 0% 177 1 1 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% C 70% m L F 60% a`) C ii 50% c 2 40% a- 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) S eg 7S i to 12123 02/06/02 ii zi al!s 'L lualu 3S 'Z65*Ll M Cedar River Gravel Study Data Summary for Site No.13, Cross Section No. 60, Located in Segment 7 at River Mile 17.163 Segment Summary Segment 7 is 1.427 miles long, extending from RM 18.000 to RM 16.573. It is generally described as: Upper Dorre Don, variable confinement. Average gradient is estimated to be 0.48. Known local sediment sources are: Minor (50 ft high day cliff with sand at RM 17.3). Data collected during this study include: Sites 12-13. Other studies active in this segment include: None. Subsegment Summary Description: Flood study cross-section 60. (Intended cross-section study site in original gravel study sampling plan was 59, 60 was chosen by mistake. Per our observations, ASA is significantly reduced at XS 60, compared to XS 59.) Widths and Depths Surveyed Width (ft) 79.5 BF Width (ft) 67.0 BF Depth ft 3.73 Width/Depth Ratio (ft/ft) 18.0 Bed Width ft 59.0 Active Width (ft) 59.0 Active Depth (ft) 0.74 Confinement and Banks 10 yr Width ft 350.0 10 yr/BF Ratio 5.22 BF Elevation (ft, datum) 98.6 10 yr Elevation (ft, datum) 365.16 LB RB Est. % Levee 0 100 Est. % Revetment 0 100 Bank Ht., Typical ft 6 12 Bank Ht., Max (ft) 8 12 Material Source alluvial ri rap Dom/Subdom Size L.Cob/S.Cob rips Bank Size Relative to Bed >75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types None Gross Spawn Area (sq. ft.) 8978 Percent Usable 10 ASA . ft. 897.8 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment 1 adult sockeye Fish Observed, adj. Segment 2 adult sockeye Gradients Survey Length (ft) 134.0 Water Surface Slope (ft/ft 0.0012 Avg Bed Slope (ft/ft) -0.0022 L25 Bed Slope (ft/ft) -0.0017 M50 Bed Slope (ft/ft) -0.0040 R75 Bed Slope ft/ft -0.0010 Geomorphology Bed Morphology Plane bed Channel Pattern Single Subsegment Adj. Segment Gravel Bar Type None None Bar Material Typ. Bar Width (ft) Max. Bar Width (ft) Max. Bar Width (cw Bar Vegetation Fine Sediment In Riffles Local, sheltered locations In Pools N/A Cobble Embeddedness <15% Notes, Comments Q = 96 at Landsburg Below Div. Datum: Relative Bankfull Confidence: nd Bankfull Indicators: nd ASA Deductions: substrate too large Pebble Counts ID A B C D Method Count None None None Cross Section Location 77 to 18 0 to 0 0 to 0 0 to 0 Sizes mm Maximum mobile 310 nd nd nd Maximum 225 nd nd nd d84 161 nd nd nd d50 81 nd nd nd d16 40.5 nd nd nd Minimum 5.50 nd nd nd Seg7Site13.123 02/06/02 Segment 7, Site No.13 Cross Section No. 60, at River Mile 17.163 Channel Cross Section Bankfull Width = 67.0 ft.; Bankfull Depth = 3.73 ft. 106 > 105 m 104 103 102 101 p 100 99 R Fr ^ If w 98 c 97 0 96 B 95 w 94 93 0 10 20 30 40 50 60 70 80 90 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 59.0 ft.; Active Width = 59.0 ft.; Active Depth = 0.74 ft. ,. 106 > 105 m 104 103 to E 102 101 p 100 99 R 98 y c 97 0 96 XC 95 T Q) 94 w 93 — 0 10 20 30 40 50 60 70 80 90 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0012 and Avg Bed Gradient =-0.0022 96 m a� E 95 m — — — — — — — — — — — — — — — — — v94 — --- ° -- — — — — - — — — — — — — — — — — — — — — — — — —i m w 93 80 60 40 20 0 -20 -40 -60 -80 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) f BedEl L -11 Bed El M -A- Bed El R -+' WaterSurface Seg7Site13.123 02106/02 Segment 7, Site No.13 Cross Section No. 60, at River Mile 17.163 Pebble Count Statistics 320 - - - 300 280 - - 260 240 - 220 Max 200 d84 180 - d 16 u) 160 Min a� 140 120 o_ 100 • MaxMob 80 - 60 E- - - 40 - 20 0 A,77to18 B4Oto0 C,0to0 D,0to0 Pebble Count Pebble Count Statistics (zoom) 180 310 - - 160 16' -- 140 120 Max E d84 N 100 - - d16 in - - - Min a) 80 -- • d50 cu 60 - -- - - • MaxMob 40 - 20 - — 0 A,77to18 B4Oto0 C,0to0 D,0to0 Pebble Count Seg7Sitel 3.123 02/06/02 Segment 7, Site No.13 Cross Section No. 60, at River Mile 17.163 Pebble Count A 100% 5 90% 80% C 70% L 60% 61 m C ii 50% c v a`40% ) a 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% 90% 80% 70% a3 L ~ 60% a) C 50% aa) 40% U d 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% c 70% m L 60% Q) C i 50% c 40% 2 a 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Seg7S ite 13.123 02/06/02 T i .- �.� �,•��!r,+Nity u� +- r tiHN `JIS1 L� V(rovwI, LAw111 01� L'WE/(,rut/ 1iaJ)E . DENo�ES L,ti1e Arc-oss Fat >�-SCc7(o��, CtJ��cv� ; O'J (- h-"N 0, A 5 nJ rs. P C O+J V4 T-1 UJ \i H J y A - (; VFW R u N 6wF-Ki -P LEF \ Dr O((A,J(,� Lv1F `'A-&PTCi o 3 P 0^3 t iN,F Coles dF a\ee-v i v-E ES , 4 W-W jo OF i'-T (Z-D `Tot LP, vaS oct TAT. ht)Js'E A 0 n 'ce-1 "J61c ON LOFT 13n��c is FA�¢�Y F( A~� A4iov� scvPFr��a �: � � o � o o e3� o� N Flo P IV -o OVA-3 K RS - j Ak, �b M , Cedar River Gravel Study Data Summary for Site No.14, Cross Section No. 50, Located in Segment 8 at River Mile 16.159 Segment Summary Segment 8 is 0.975 miles long, extending from RIv1 16.573 to RM 15.598. It is generally described as: Lower Dorre Don , unconfined. Average gradient is estimated to be 0.64. Known local sediment sources are: Negligible? (Dorre Don side channel at RM 15.9). Data collected during this study include: Sites 14-15: side channel pebble count. Other studies active in th',s segment include: None. Subsegment Summary Description: Flood study cross-section 50, per survey notes. Widths and Depths Surveyed Width (ft) 158.0 BF Width (ft) 66.3 BF Depth ft 3.75 Width/Depth Ratio (fttft) 17.7 Bed Width ft 58.8 Active Width ft 58.8 Active Depth (ft) 1.08 Confinement and Banks 10 yr Width ft 460.0 10 rBF Ratio 6.94 BF Elevation ft, datum) 336.9 10 yr Elevation ft, datum 338.67 LB RB Est. % Levee 0 0 Est. % Revetment 0 0 Bank Ht., Typical (ft) 4 4 Bank Ht., Max (ft) 5 5 Material Source alluvial alluvial Dom/Subdom Size S.Cob/L.Cob S.Cob/L.Cob Bank Size Relative to Bed >75% < as. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types None Gross Spawn Area (sq. ft.) 8791 Percent Usable 5 ASA . ft. 439.55 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment None Fish Observed, adj. Segment 18 Adult sockeye-18-20", 3 resident trout - 8" Gradients Survey Length (ft) 132.0 Water Surface Slope (ft/ft 0.0016 Avg Bed Slope (ft/ft) 0.0071 L25 Bed Slope (ft/ft) 0.0017 M50 Bed Slope ft/ft) 0.0045 R75 Bed Slope ft/ft) 0.0150 Geomorphology Bed Morphology Plane bed Channel Pattern Single Subsegment Adj. Segment Gravel Bar Type None None Bar Material Typ. Bar Width (ft) Max. Bar Width (ft) Max. Bar Width cw Bar Vegetation Fine Sediment In Riffles Local, sheltered locations In Pools Local, obstruct, slack Cobble Embeddedness <15% Pebble Counts Notes, Comments ID A B C D Method Count None None None Cross Section Location 158 to 91 0 to 0 0 to 0 0 to 0 Sizes mm Maximum mobile 321 nd nd nd Maximum 321 nd nd nd d84 113 nd nd nd d50 57 nd nd nd d16 28.5 nd nd nd Minimum 1.50 nd nd nd Seg8Site14.123 02/06/02 Segment 8, Site No.14 Cross Section No. 50, at River Mile 16.159 Channel Cross Section Bankfull Width = 66.3 ft.; Bankfull Depth = 3.75 ft. 341 - 340 p z339 338 337 BF m 336 a� 335 334 F I- R c B m 333 332 T a>i w 331 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 58.8 ft.; Active Width = 58.8 ft.; Active Depth = 1.08 ft. 341 p 340 > 339 E 338 F 337 B 336 w335 " 334 P c C 333 r a>i 332 T w 331' 0 10 20 30 40 50 60 70 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0016 and Avg Bed Gradient = 0.0071 335 CO 00 0 z 334 - - - E ♦_ m ' — 333 ----- — ----------- _— — — — — —— ----� 0 332 .2 w 331 80 60 40 20 0 -20 -40 -60 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) f BedEl L+ BedEl M t BedEl R-A- WaterSurface -80 Seg8Site14.123 02/06/02 Segment 8, Site No.14 Cross Section No. 50, at River Mile 16.159 340 320 300 280 260 240 E 220 v 200 N 180 160 140 a_ 120 100 80 60 40 20 0 Pebble Count Statistics Max d84 d16 Min • d50 • MaxMob 41-121 A,158to91 B4Oto0 C,0to0 D,0to0 Pebble Count Pebble Count Statistics (zoom) 140 321 120 —113 100 E Max E d84 N 80 d16 in Min aD 60 7 • d50 I • MaxMob 40 20 0 A,158to91 B4Oto0 C,0to0 D,0to0 Pebble Count Seg8Site14.123 02/06/02 Segment 8, Site No.14 Cross Section No. 50, at River Mile 16.159 Pebble Count A 100% 32 90% 13 80% c 70% m L 57 60% N C ii 50% C 2 40% °1 a 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% 90% 80% 70% L ~ 60% N C i 50% a 40% U 30% 20% 10% 1 1+ 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% I 80% m 70% L ~ 60% a: c E 50% ac) 40% 2 a(') 30% 20% 10% I I i 10 100 Particle Size (mm) Seg8Site14.123 1000 02/06/02 0 Ci cu CN tn rl Q \ C LEFT O VE66T..zo•J �5 Ec\bVOJS . r,►.�►,1�( o�._ �t��a 45 ;F" LEFTK I kLrJE'KS, A FCv 5. apt law LCAP w.oP(AS, 1 Rlbw an�,� oa GRass\4- w\ZN ��• cr ��u AFPF4R5 �w�o o �,>F eS NA4E C.)T 1 ow a rw,icK e� of -TOR VEc�lviaTloa' Tie d\E„� %ACG£�: 1c AV riG�uLYd- 1SkE (EFT 3+.ac sS RbV�R �� SuBS�b 1 1 TCC.K\(ICoritec FoR- $� 710 H314SES. — d - Z..-r5 -gArJilCLOAt 4 I{pJSE Ittree �s A �(MILt Y�+EckwglEe c4�•�wtEt�i 3E - UNOWZ�JT� X-SECTW^� CW E FEUAo s A, Q. i-n oFF ox gpk A EEL) T 60' U S of ��©O �O NISYaR(C C14ANNCL .-lo YA2O of AooSE. AFYC�L; QC)OOOv� Q Ci O OQ ^ O O _R'P-RAP wA-UL. t*Abow;l Nat mlZ vu*-( 4+�S }{ojSE Wks JS 0,30L,- ¢ R\VGK PtLotiT( PROPDc1� C�10U1 ��S AwMI PRow� (It\S lS TttE 6�D fMa.�JE� , cad �,►Ar�`�y� • r?a`\� L/kaDow.uEt_ iM(S iNF C'IA.�Nfi RWCrC�� IN \.v6l it V>-rtok -rat "Llb F.ec_D ,V�61 `►T (,M y, �G� Cam �. / "�5�; Ni�VL� 'lo C �4RG;C ko c..:TtaJ `SOD. 4 .. A_.1-oa .3a^ti. CAt5ca mAE SZ*sC-T- -to D\4gzT •(� �) • SwPC S4 "' yl6�tE 3 -y YEAcf Evc;t wINYr2 -tH.ts hecq 15 P \e Ta -me LE�C. 6VEty Yc-- 'me Acc-A of Sipe R ;0 CA?' f"k15(gy VoJbrtt .A'tr.'L . EI<cav-t• L,..f. i`. -----Z Tor of 3A�K , NRA55 IS FWODp� ' SEE 3kcstG 'ChatC I.A�GE2 Dap J1,� ucw P3'D 7Si • • Z30 — so / • Zo zs% T4a,LwE6, L68/LE W Tally 0 0 0 0 0 0 1 2 2 10 12 25 18 16 2 2 4 2 0 0 5 101 Dorre Don Side Channel Pebble Count Side Channel of Mainstem Segment No. 8 with Mouth at River Mile 15.869 Nearest Downstream Study Site: Segment 8, Site 15 at River Mile 15.765 Particle Size Bedrock VL Boulder; 2049-4096 L Boulders 1025-2048 M Boulders 513-1024 S Boulders 385-512 S Boulders 257-384 L Cobbles 193-256 L Cobbles 129-192 S Cobbles 97-128 S Cobbles 65-96 VC Gravel 49-64 VC Gravel 33-48 C Gravel 25-32 C Gravel 17-24 M Gravel 13-16 M Gravel 9-12 F Gravel 7-8 F Gravel 5-6 VF Gravel 3-4 Sand 1-2 Sa/Si/CI <1 Pct Dist Cum Dist 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 1.0% 100% 2.0% 99% 2.0% 97% 9.9% 95% 11.9% 85% 24.8% 73% 17.8% 49% 15.8% 31 % 2.0% 15% 2.0% 13% 4.0% 11% 2.0% 7% 0.0% 5% 0.0% 5% 5.0% 5% 260 240 220 200 180 E E 160 N 140 in a� 120 U 100 o_ 80 60 40 20 0 Pebble Count Statistics Pebble Count Max d84 d16 Min • d50 • MaxMob Dorre Don Side Channel Pebble Count 100% 5 90% Wort 80% c 70% 1 ca L 60% N c ii 50% c v 40% `m o- 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Notes: Additional sample collected by Jones & Stokes on 09/25/01 Side channel is -1600 ft long; pebble count taken -1000 ft u/s of mouth. Exact location is in riffle located 65 ft u/s of bridge on Dorre Don Ct. SE. Bankfull width -18 ft; active width -15 ft. Photos: Roll 8, Frames 5, 6, 7. No fish observed. Seg8Dorre Don Side Channel.123 02/06/02 Cedar River Gravel Study Data Summary for Site No.15, Cross Section No. 45m, Located in Segment 8 at River Mile 15.765 Segment Summary Segment 8 is 0.975 miles long, extending from RM 16.573 to RM 15.598. It is generally described as: Lower Dorre Don , unconfined. Average gradient is estimated to be 0.64. Known local sediment sources are: Negligible? (Dorre Don side channel at RM 15.9). Data collected during this study include: Sites 14-15; side channel pebble count. Other studies active in this segment include: None. Subsegment Summary Description: -30' downstream of flood study cross-section 45, per King Co survey notes Widths and Depths Surveyed Width (ft) 130.5 BF Width (ft) 117.0 BF Depth (ft) 3.36 Width/Depth Ratio (ft/ft) 34.9 Bed Width ft 96.4 Active Width ft 99.5 Active Depth (ft) 0.83 Confinement and Banks 10 yr Width ft 740.0 10 yr/BF Ratio 6.32 BF Elevation (ft, datum) 326.8 10 yr Elevation (ft, datum) 329 LB RB Est. % Levee 0 85 Est. % Revetment 0 85 Bank Ht., Typical ft 4 5 Bank Ht, Max (ft) 6 6 Material Source alluvial rips alluvial Dom/Subdom Size Gr/Cob ri rap/Gr/Co Bank Size Relative to Bed >75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Glide Secondary Habitat Types Riffle Gross Spawn Area (sq. ft.) 19300 Percent Usable 60 ASA .ft. 11580 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment None Fish Observed, adj. Segment Gradients Survey Length (ft) 230.0 Water Surface Slope ft/ft 0.0090 Avg Bed Slope ft/ft) 0.0036 L25 Bed Slope (ft/ft) 0.0096 M50 Bed Slope (fUft) 0.0069 R75 Bed Slope ft/ft -0.0057 Geomorphology Bed Morphology Plane bed Channel Pattern Single Subsegment I Adj. Segment Gravel Bar Type Point None Bar Material Cob/Gr Typ. Bar Width (ft) 45 Max. Bar Width ft 60 Max Bar Width (cw) 0.5 Bar Vegetation Encroaching vegetation Fine Sediment In Riffles Local, sheltered locations In Pools WA Cobble Embeddedness 15-35% Notes, Comments Q = 112 at Landsburg Below Div. Datum: NAVD88 Bankfull Confidence: nd Bankfull Indicators: nd ASA Deductions: large substrate Pebble Counts ID A B C D Method Count None None None Cross Section Location 119 to 23 0 to 0 0 to 0 0 to 0 Sizes (mm) Maximum mobile 258 nd nd nd Maximum 225 nd nd nd d84 113 nd nd nd d50 57 nd nd nd d16 28.5 nd nd nd Minimum 0.10 nd nd nd Seg8Site15.123 02/06/02 Segment 8, Site No.15 Cross Section No. 45m, at River Mile 15.765 Channel Cross Section Bankfull Width = 117.0 ft.; Bankfull Depth = 3.36 ft. 330 cc CO RPIN 0 329 z 328E pt BF 327 m 326 325 — — — — — — — — — — — — — — — — — — 0 324 > (D 323 w 322 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 96.4 ft.; Active Width = 99.5 ft.; Active Depth = 0.83 ft. - 330 CO 0 329 z 328 327 BE m 326 iu 325 0 324 ate') 323 w 322 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 Distance from LB to RB (feet) — Elev — WaterSurface 325 CO CO 0 Q 324 Z 323 0 Z 322 w 320 Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0090 and Avg Bed Gradient = 0.0036 ♦��� 130 110 90 70 50 30 10 -10 -30 -50 -70 -90 -110 -130 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) f BedEl L + BedEl M } BedEl R -A� WaterSurface Seg8Site15.123 02/06/02 Segment 8, Site No.15 Cross Section No. 45m, at River Mile 15.765 280 260 240 220 200 E 180 a; 160 N in 140 120 100 80 60 40 20 0 Pebble Count Statistics Max d84 d16 Min • MaxMob 4258 113 A,119to23 B4Oto0 C,0to0 D,0to0 Pebble Count 120 100 E E 80 N in U 60 a 40 20 0 Pebble Count Statistics (zoom) Max d84 d16 Min • d50 • MaxMob ss 113 7 A,119to23 B4Oto0 C,0to0 D,0to0 Pebble Count Seg8Site 15.123 02/06/02 Segment 8, Site No.15 Cross Section No. 45m, at River Mile 15.765 Pebble Count A 100% 5 90% 80% c 70% m L 60% N C ii 50% c u 40% 2 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% 90% 80% c 70% m L 60% N C ii 50% c v 40% `m d 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% C 70% m L 60% N C iz 50% c 40% - d d 30% 20% - 10% - 0% 1 10 100 1000 Particle Size (mm) SegBSite15.123 02106,02 RM 15.765, Segment 8, Site 15 - - - --- - - -z - - - T I F I t Q I � I � f = I � U � i T. 1 qp N i r- - - Cedar River Gravel Study Data Summary for Site No.16, Cross Section No. 36, Located in Segment 9 at River Mile 14.906 Segment Summary Segment 9 is 0.848 miles long, extending from RM 15.598 to RM 14.750. It is generally described as: Maple Valley confined, steeper. Average gradient is estimated to be 0.63. Known local sediment sources are: None observed. Data collected during this study include: Sites 16-17; lateral bench point pebble count. Other studies active in this segment include: None. Subsegment Summary Description: Flood Study XS 36--3rdCross-Section D/S of SR 18, at concrete retaining wall; could not find precise location or BM Widths and Deaths Surveyed Width (ft) 116.6 BF Width (ft) 99.1 BF Depth (ft) 3.11 Width/Depth Ratio (ft/ft) 31.8 Bed Width (ft) 81.0 Active Width (ft) 87.4 Active Depth (ft) 1.06 Confinement and Banks 10 yr Width (ft) 150.0 10yr/BF Ratio 1.51 BF Elevation (ft, datum) 95.2 10 yr Elevation (ft, datum) 302.65 LB RB Est. % Levee 0 0 Est. % Revetment 100 0 Bank Ht., Typical (ft) 6 6 Bank Ht., Max (ft) 8 8 Material Source alluvium alluvium Dom/Subdom Size Gr/Cob Gr/Cob Bank Size Relative to Bed >75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types None Gross Spawn Area (sq. ft.) 12355 Percent Usable 25 ASA (sq. ft.) 3088.75 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment None Fish Observed, adj. Segment Gradients Survey Length (ft) 198.0 Water Surface Slope (ft/ft: 0.0067 Avg Bed Slope (ft/ft) 0.0047 L25 Bed Slope (ft/ft) 0.0047 M50 Bed Slope (ft/ft) 0.0046 R75 Bed Slope (ft/ft) 0.0047 Geomoroholoov Bed Morphology Plane bed Channel Pattern Single Subsegment Adj. Segment Gravel Bar Type None Lateral Bar Material Boulder Typ. Bar Width (ft) Max. Bar Width (ft) 62 Max. Bar Width (cw) 0.6 Bar Vegetation N/A Encroaching vegetation Fine Sediment In Riffles Local, sheltered locations In Pools N/A Cobble Embeddedness nd u^roc r.,,,,n -+Q Lateral bar located u/s of subsegment Q = 112 at Landsburg Below Div. Datum: Relative Bankfull Confidence: Mod Bankfull Indicators: Eroded LB with Veg. Line; gabions RB ASA Deductions: deduct for too coarse Pebble Counts ID A B C D Method Count None None None Cross Section Location 48 to 104 0 to 0 0 to 0 0 to 0 Sizes (mm) Maximum mobile 450 nd nd nd Maximum 321 nd nd nd d84 161 nd nd nd d50 57 nd nd nd d16 40.5 nd nd nd Minimum 0.10 nd nd nd Seg9Sitel 6.123 02/06/02 Segment 9, Site No.16 Cross Section No. 36, at River Mile 14.906 Channel Cross Section Bankfull Width = 99.1 ft.; Bankfull Depth = 3.11 ft. 101 a) _>— 100 m 6 w 99 E 98 97 96 BF R F w 95 c ° ------------------- m 93 PC T 8 a>i 92 w 91 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 81.0 ft.; Active Width = 87.4 ft.; Active Depth = 1.06 ft. 101 m 2 io 100 m 99 98 m 97 96 BF R F z 95 I 94 -- ------ — cc 93 T------ P PC a2 92 w 91 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0067 and Avg Bed Gradient = 0.0047 95 m m � 94 E m 0 93 — -- A, —— ---- c 92 m w 91 110 90 70 50 30 10 -10 -30 -50 -70 -90 -110 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) i BedEl L 4 BedEl M t Bed El R -rr WaterSurface Seg9Site16.123 02/06/02 Segment 9, Site No.16 Cross Section No. 36, at River Mile 14.906 Pebble Count Statistics 480 440 0450 - - 400 — - - - - 360 320 Max E d84 280 d16 N in 240 Min a� 200 • d50 a- 160 • MaxMob 120 80 40 0 ` A,48to104 B4Oto0 C,0to0 D,0to0 Pebble Count Pebble Count Statistics (zoom) 200 450 180 160 1 140 - - - - - -- - -- Max 120 d84 N - - ---- - -- -- - d16 0 100 - - - - - Min ID F 80 • d50 cu a_ 60 • MaxMob T 40 20 - - 0 A,48to104 B4Oto0 C,0to0 D,0to0 Pebble Count Seg9Site16.123 02/06 02 Segment 9, Site No.16 Cross Section No. 36, at River Mile 14.906 Pebble Count A 100% 32 90% 80% c 70% m L 60% 57 `m i 50% c c2i 40% iv 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% 90% 80% c 70% m L i: 60% N C ii 50% c 40% m d 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% c 70% m t 60% m c ii 50% c 40% `m a 30% 20% 10% 0% — I - - i �- - --Lj 1 10 100 1000 Particle Size (mm) Seg9Site16.123 02'06i02 RM 14.906, Segment 9, Site 16 r Tally 0 0 0 0 0 0 0 1 0 12 22 32 12 11 7 3 0 1 1 1 2 105 Low Bench Pebble Count On Mainstem Segment No. 9 at River Mile 14.757 Nearest Study Site: Segment 9, Site 17 at River Mile 14.757 Particle Size Bedrock VL Boulder: 2049-4096 L Boulders 1025-2048 M Boulders 513-1024 S Boulders 385-512 S Boulders 257-384 L Cobbles 193-256 L Cobbles 129-192 S Cobbles 97-128 S Cobbles 65-96 VC Gravel 49-64 VC Gravel 33-48 C Gravel 25-32 C Gravel 17-24 M Gravel 13-16 M Gravel 9-12 F Gravel 7-8 F Gravel 5-6 VF Gravel 3-4 Sand 1-2 Sa/Si/CI <1 Pct Dist Cum Dist 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 1.0% 100% 0.0% 99% 11.4% 99% 21.0% 88% 30.5% 67% 11.4% 36% 10.5% 25% 6.7% 14% 2.9% 8% 0.0% 5% 1.0% 5% 1.0% 4% 1.0% 3% 1.9% 2% 170 160 150 140 130 _ 120 E 110 E 100 N 90 U) 80 a� 70 60 50 40 30 20 10 0 Pebble Count Statistics Max d84 d16 Min • d50 • MaxMob 57 Pebble Count Low Bench Pebble Count 100% 161 90% 7 80% 70% cc s 1 60% C ii 50% c 40% m 30% 1 20% 10% 0% 1 10 100 1000 Particle Size (mm) Notes: Additional sample collected by Jones & Stokes & Sue Perkins on 09/26/01 Identified as a highly utilized spawning area and an alternative subsurface sample site; was flowing fairly fast and 4" to 6" deep at time of visit. Few sockeye spawning on bench. Surface point count only. This pebble count was limited to a low lateral bench along the RB, with the survey width corresponding approximately to 117 ft to 127 ft on the cross section for Segment 9, Site 17. The d/s end of this bench was a subset of Site 17's Pebble Count A, which extended from 50 ft to 130 ft. Downpour! Seg9Low Bench.123 12/04/01 Cedar River Gravel Study Data Summary for Site No.17, Cross Section No. 35, Located in Segment 9 at River Mile 14.757 Segment Summary Segment 9 is 0.848 miles long, extending from RM 15.598 to RM 14.750. It is generally described as: Maple Valley confined, steeper. Average gradient is estimated to be 0.63. Known local sediment sources are: None observed. Data collected during this study include: Sites 16-17; lateral bench point pebble count. Other studies active in this segment include: None. Subsegment Summary Description: Flood Study Cross Section 35, per King Cc survey notes Widths and Depths Surveyed Width (ft) BF Width (ft) BF Depth (ft) 100.0 92.4 2.52 Width/Depth Ratio (ft/ft) 36.6 Bed Width (ft) 80.5 Active Width (ft) 80.5 Active Depth (ft) 0.59 Gradients Survey Length (ft) 184.0 Water Surface Slope (ft/ft; 0.0022 Avg Bed Slope (ft/ft) 0.0019 L25 Bed Slope (ft/ft) -0.0005 M50 Bed Slope (fVft) -0.0005 R75 Bed Slope (ft/ft) 0.0067 Geomorpholo, Confinement and Banks Bed Morphology Plane bed 10 yr Width (ft) 115.0 10 yr/BF Ratio 1.24 1 BF Elevation (ft, datum) 295.1 10 yr Elevation (ft, datum) 297.7 LB RB Est. % Levee 0 0 Est. % Revetment 60 10 Bank Ht., Typical (ft) 4 6 Bank Ht., Max (ft) 4 6 Material Source Alluvium Alluvium Dom/Subdom Size Cob/Gr Cob/Gr Bank Size Relative to Bed 25-75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types None Gross Spawn Area (sq. ft.) 14546 Percent Usable 75 ASA (sq. ft.) 10909.5 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment None Fish Observed, adj. Segment None Pattern Gravel Bar Typ Bar Material TVD. Bar Width Bar Fine_ Sediment In Riffles Local, sheltered locations In Pools N/A Cobble Embeddedness <15% Notes, Comments O =108 at Landsburg Below Div, Datum: NAVD88 Bankfull Confidence: Mod Bankfull Indicators: RB: 14" alder rooting line in revetment; LB: slope break & top of gradual "bar" at margin ASA Deductions: nd Pebble Counts ID A B C D Method Count None None None Cross Section Location 50 to 130 0 to 0 0 to 0 0 to 0 Sizes (mm) Maximum mobile 390 nd nd nd Maximum 321 nd nd nd d84 113 nd nd nd d50 57 nd nd nd d16 28.5 nd nd nd Minimum 1.50 nd nd nd Seg9Site17.123 02/06/02 Segment 9, Site No.17 Cross Section No. 35, at River Mile 14.757 Channel Cross Section Bankfull Width = 92.4 ft.; Bankfull Depth = 2.52 ft. 104 CO > 103 z 102 E 101 R JIF is 100 .2 99 — — — — — — — — c 98 . T > 97 D w 96 20 30 40 50 60 70 80 90 100 110 120 130 140 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 80.5 ft.; Active Width = 80.5 ft.; Active Depth = 0.59 ft. - 104 CO > 103 z 102 � 101 M 100 99 98 M T > 97 m w 96 20 30 40 50 60 70 80 90 100 110 120 130 140 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0022 and Avg Bed Gradient = 0.0019 294 CO CO Z E 293 ♦ _ m o — °' -- -- i —— ♦---——————— — — — — —— o y m w 291 110 90 70 50 30 10 -10 -30 -50 -70 -90 -110 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) BedEl L � BedEl M t Bed El R -t WaterSurface Seg9Site17.123 02/06/02 Segment 9, Site No.17 Cross Section No. 35, at River Mile 14.757 Pebble Count Statistics 400 - - �390 360 320 E 280 Max E d84 240 d16 N Cf) 200 Min a) U 160 • d50 a • MaxMob 120 113 80 40 0 A,50to130 B4Oto0 C,0to0 D,0to0 Pebble Count 200 180 160 140 120 N-113 in 100 m 80 o_ 60 40 20 0 Pebble Count Statistics (zoom) so Max d84 d16 Min • d50 • MaxMob - - - - __ __ 57 - - - A, 50 to 130 B, 0 to 0 C, 0 to 0 D, 0 to 0 Pebble Count Seg9Site17.123 02/06/02 Segment 9, Site No.17 Cross Section No. 35, at River Mile 14.757 Pebble Count A 100% 32 90% 80% c 70% m L E- 60% m` c iL 50% c 40% m` a 30% 20% - 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% 90% 80% c 70% m 60% d ii 50% C cmi 40% N Q. 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% I c 70% m L H 60% y` I iL 50% C U 40% CL 30% 20% 10% I 0% 1 10 100 1000 Particle Size (mm) Seg9Site17.123 02/06/02 RAI 14.757, Segment 9, Site 17 O■■■■■■■■■■■■■■■■■■■ ■■■■j ■ ■N■■■■■ ■■■■■■■ ■■■■■■■■■ ENE ■■■ ■■i■ ■■■■■■■■■■■■■■■■■■■■■■■■■■■ ■■■■■■■■■■■■■■■■■■■■■'N■■■E■ ■I&I ro ■■■ ■■tea■ ■■■■■■ OEM ■■■■■■■■■■■■■■■■■■■■■■■ ■■■■■■■■■■■■■■■■■■■EE■■■■■N�i ■■■■■■■■■■■■■■■■■■■■■■■■■■■ ■■■■■■■■■■■■■■■■■■■■■■■■■■■ ■■■■■■■ ■■■E■■■!■■■■■N■■ ■■■■■■■■■■■■■■■■■■■■■ OEM ■■ ■■■■■■■■■■■■■■■■■■■■■■■■■■� ■■■■■■■■■■■■■■■■am ■■■N■■■■■■■ ■■■■■■■■■■W■■■■■■■■ ■■■/■■■i�INIl■■■■■■■■■■■■ N■ ■W�■■■■■■ ■■■■■■ ■r�,��,.■■�■■®■■■■■■■ ■!ialyr�■ ■■■►�■■■■■■IRM wM■■■ ■■m ■■■■■■■®■ - ■■ ■■■■[�s SON■I'�■■■■® _■■■■ - ■■■ ■■■■■■■■E'er r■: !0 �, ■1rJBE ■■■■■■■■■■�/■■■■NEEr��J�l!■1� ■■■■■■■■■■ ■■■■■■■■■ L�■rIN �i■1� ■■■■■■E ■■■e■ME■■■■■\ ■■�■� ■■■■■■E:!■w■�II�EO■■■■ ME i■� ■■■■■■ MINE ■■■ ■■!!■■■�i■i i!:!■■■■■■■■■■■■1�■IiN �►►ZIC ►�■■■■■/■!EN■■■MINEM■■ii! ■■ ■N�►�I■■EQ■el■mo■■■■■I■■■■■ii■■ ■■■'■■■�■■i■■�1■■ ■■■I/■■■■■■■ ■■■■■■■■■t■■■■■■■■■■■■■■■■■ �■■■■■■■■■►�■■■n■■■■;■■■■■■■■ ■■■■■■■■■■■■�/�■■■■■■■■■■■■ EENNEE■NN■■■\IEE■■■■■NNE■■ ■■■■■■■■■■■■■■■NEON■■■■■■■■ Cedar River Gravel Study Data Summary for Site No.18, Cross Section No. 33, Located in Segment 10 at River Mile 14.575 Segment Summary Segment 10 is 0.686 miles long, extending from RM 14.750 to RM 14.064. It is generally described as: Flatter, variable confinement; Peterson Cr.. Average gradient is estimated to be 0.46. Known local sediment sources are: 1990/1996 landslides, diffs at RM 14.2—revetment barrier prevents transport to stream; Peterson Cr, Ig trib source of coarse sed at RM 14.4. Data collected during this study include: Site 18; Peterson Cr pebble count. Other studies active in this segment include: None. Subsegment Summary Description: Flood study Bross -section 33 (per King Cc flood study survey notes) Widths and Denths Surveyed Width (ft) 120.0 BF Width (ft) 89.6 BF Depth (ft) 2.92 Width/Depth Ratio (ffft) 30.7 Bed Width (ft) 74.4 Active Width (ft) 74.4 Active Depth (ft) 0.60 Confinement and Banks 10 yr Width (ft) 210.0 10 /BF Ratio 2.34 BF Elevation (ft, datum) 98.8 10 yr Elevation (ft, datum) 293.84 LB RB Est. % Levee 0 0 Est. % Revetment 0 0 Bank HL, Typical (ft) 50 2 Bank Ht., Max (ft) 60 3 Material Source G.T. alluvial Dom/Subdom Size Sa/Gr Cob/Gr Bank Size Relative to Bed 25.75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types Gross Spawn Area (sq. ft.) 13172 Percent Usable 60 ASA (sq. ft.) 7903.2 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment None Fish Observed, adj. Segment 1 salmonid, 3" trout? Gradients Survey Length (ft) 180.0 Water Surface Slope (ft/ft; 0.0029 Avg Bed Slope (ft/ft) 0.0015 L25 Bed Slope (ftfft) -0.0001 M50 Bed Slope (ft/ft) -0.0013 R75 Bed Slope (ft/ft) 0.0059 Geomo Bed Morphology Channel Pattern Bar Material Cob/E Typ. Bar Width (ft) 50 Max. Bar Width (ft) 62 Max. Bar Width (cw) 0.7 Bar Veaetation Bare of vex Fine Sediment In Riffles Local, sheltered locations In Pools Patches + local Cobble Embeddedness 15-35% Notes. Comments Subsegment gravel bar is at upstream end of transect. Q = 108 at Landsburg Below Div. Datum: Relative Bankfull Confidence: nd Bankfull Indicators: nd ASA Deductions: high velocity, large substrate Pehhle Counts ID A B C D Method Count None None None Cross Section Location 43 to 117 0 to 0 0 to 0 0 to 0 Sizes (mm) Maximum mobile 320 nd I nd nd Maximum 321 nd nd nd d84 113 nd nd nd d50 41 nd nd nd nd nd d16 14.5 nd nd Minimum 0.10 nd nd Seg10Site18.123 02/06/02 Segment 10, Site No.18 Cross Section No. 33, at River Mile 14.575 Channel Cross Section Bankfull Width = 89.6 ft.; Bankfull Depth = 2.92 ft. 101 a� .i 100 E 99 is 0 98 97 T8---------------fit m c 96 0 T > 95 aT w 94 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 74.4 ft.; Active Width = 74.4 ft.; Active Depth = 0.60 ft. 101 a1 .i 100 m 99 B E m 0 98 97 C o---------------P 96 0 > 95 T m w 94 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0029 and Avg Bed Gradient = 0.0015 98 m .6 6 of 97 E — — — 96 — — n, ■ — — — — — — — — — — — — — — — — — — — = i a� --- gg m w 94 100 80 60 40 20 0 -20 -40 -60 -80 -100 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) f BedEl L � BedEl M A Bed El R -+- WaterSurface SegIOSite18.123 02/06/02 Segment 10, Site No.18 Cross Section No. 33, at River Mile 14.575 340 320 300 280 260 240 E220 v 200 N 180 ,D 160 140 a 1201 100 80 60 40 20 0 Pebble Count Statistics Max d84 d16 Min • d50 • MaxMob -3 A,43to117 B4Oto0 C,0to0 D,0to0 Pebble Count 140 120 100 E N 80 Un aD E 60 a 40 20 0 Pebble Count Statistics (zoom) Max d84 d16 Min • d50 • MaxMob 20 —113 A,43to117 B4Oto0 C,0to0 D,0to0 Pebble Count Seg 10Site 18.123 02/06/02 Segment 10, Site No.18 Cross Section No. 33, at River Mile 14.575 Pebble Count A 100% 32 90% 80% c 70% m L 60% N C ii 50% c 2 40% a� a 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% 90% 80% c 70% m L 60% `m c E 50% c 2 40% m d 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% c 70% m L 60% 41 C 6- 50% C 40% QI a 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Seg t OSite 18.123 02/06/02 RM 14.575, Segment 10, Site 18 ." M MINI 'NO M- i�r;�r�rl ME MEN Now" ME ►El§ ai E 0 No ME MEMM E M w=5 1 :25—am MEN MEMO ME Vs M A MEN MEN �MME MEN,ME ME LAU MEN ON ME ME MEE 0 MEN 10"lM�®lf/WEN �ii������v BE ME lw%M ME �MEMAE M��� �MEEM���1�� �WEEMS MEl� ar�1,MMMMM ���� IX- OMEN ]I�NM1111�®!: M��� MWE �lri SIN Tally 0 0 0 0 0 0 3 23 18 22 16 8 5 2 3 2 1 1 1 1 1 107 Peterson Creek Pebble Count Tributary to Mainstem Segment No. 10 at River Mile 14.447 Nearest Downstream Study Site: Segment 10, Site 19 at River Mile 14.012 Particle Size Bedrock VL Boulder; 2049-4096 L Boulders 1025-2048 M Boulders 513-1024 S Boulders 385-512 S Boulders 257-384 L Cobbles 193-256 L Cobbles 129-192 S Cobbles 97-128 S Cobbles 65-96 VC Gravel 49-64 VC Gravel 33-48 C Gravel 25-32 C Gravel 17-24 M Gravel 13-16 M Gravel 9-12 F Gravel 7-8 F Gravel 5-6 VF Gravel 3-4 Sand 1-2 Sa/Si/CI <1 Pct Dist Cum Dist 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 2.8% 100% 21.5% 97% 16.8% 76% 20.6% 59% 15.0% 38% 7.5% 23% 4.7% 16% 1.9% 11% 2.8% 9% 1.9% 7% 0.9% 5% 0.9% 4% 0.9% 3% 0.9% 2% 0.9% 1 % 240 220 200 180 160 E 140 m N <n 120 N r 100 a- 80 60 40 20 0 Pebble Count Statistics Pebble Count Max d84 d16 Min • d50 Peterson Creek Pebble Count 100% 1 5 90% 80% c 70% m t 60% a� c ii 50% c v 40% W n 30% 20% 1 10% 0% 1 10 100 1000 Particle Size (mm) Notes: Additional sample collected by Jones & Stokes on 09/05/01 Peterson Creek is -800' downstream of Site No. 18 (Seg. 10). Pebble Count taken -50' U/S from confluence with Cedar R. in a 12 foot wide, 6% gradient riffle. Seg10Peterson Creek.123 02/06/02 Cedar River Gravel Study Data Summary for Site No.19, Cross Section No. 26, Located in Segment 11 at River Mile 14.012 Segment Summary Segment 11 is 1.926 miles long, extending from RM 14.064 to RM 12.138. It is generally described as: Bends, levees, variable confinement. Average gradient is estimated to be 0.47. Known local sediment sources are: Taylor Creek at RM 13.4 (limited fine sed only); unnamed creek at RM 12.6; 25 ft high banks at RM 12.5; Webster lake drainage at RM 12.2. Data collected during this study include: Sites 19-21; pebble counts on unnamed creek and Taylor Cr [?]. Other studies active in this segment include: None. Subsegment Summary Description: Flood study cross-section 26 (notes) Widths and Depths Surveyed Width (ft) 129.0 BF Width (ft) 115.4 BF Depth (ft) 3.22 Width/Depth Ratio (ft/ft) 35.8 Bed Width ft 102.5 Active Width ft 78.0 Active Depth (ft) 0.55 Confinement and Banks 10 yr Width ft 550.0 10 /BF Ratio 4.77 BF Elevation (ft, datum) 94.0 10 yr Elevation ft, datum 280.64 LB RB Est. % Levee 100 100 Est. % Revetment 100 0 Bank Ht, Typical (ft) 5 5 Bank Ht., Max (ft) 6 6 Material Source levee fill levee fill Dom/Subdom Size Bldr/Gr Sa/Gr Bank Size Relative to Bed >75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types Glide Gross Spawn Area . ft. 17940 Percent Usable 65 ASA .ft. 11661 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment None Fish Observed, adj. Segment Gradients Survey Length (ft) 230.0 Water Surface Slope ft/ft 0.6036 Avg Bed Slope ft/ft -0.0035 L25 Bed Slope (ft/ft) -0.0004 M50 Bed Slope ft/ft) -0.0046 R75 Bed Slope (ft/ft) -0.0056 Geomorphology Bed Morphology Plane bed Channel Pattern Single Subsegment Adj. Segment Gravel Bar Type Lateral None Bar Material nd Typ. Bar Width (ft) 24.5 Max. Bar Width (ft) 30 Max. Bar Width cw 0.3 Bar Vegetation Bare of vegetation Fine Sediment In Riffles Local, sheltered locations In Pools WA Cobble Embeddedness <15% Pebble Counts m: klommenis ID A B C D Method Count None None None Cross Section Location 40 to 143 0 to 0 0 to 0 0 to 0 Sizes (mm Maximum mobile 315 nd nd nd Maximum 225 nd nd nd d84 113 nd nd nd d50 57 nd nd nd d16 14.5 nd nd nd Minimum 0.10 nd nd nd Seg 11 Site19.123 02/06/02 Segment 11, Site No.19 Cross Section No. 26, at River Mile 14.012 Channel Cross Section Bankfull Width = 115.4 ft.; Bankfull Depth = 3.22 ft. 100 99 98 97 96 0 95 94 F F w 93 4 92 B — — — — — — — — — — 91 90 w 89 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 102.5 ft.; Active Width = 78.0 ft.; Active Depth = 0.55 ft. 100 99 a�i 98 97 If 1 96 p 95 R F w 94 w 93 c 92 ---------------- M 91 T aT 90 w 89 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0036 and Avg Bed Gradient =-0.0035 92 Cc a� 91 E ' m 90 --—————————————————————— — ----a 42 ---_— 0 89 cc w 88 130 110 90 70 50 30 10 -10 -30 -50 -70 -90 -110 -130 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) f BedEl L + BedEl M * Bed El R -rr WaterSurface Seg11 Site19.123 02/06/02 Segment 11, Site No.19 Cross Section No. 26, at River Mile 14.012 Pebble Count Statistics 340 Max d84 d16 Min • d50 - • MaxMob 320 300 280 260 240 E 220 v 200 N 180 U) a� 160 140 - cu 120 a 100 80 60 of 40 20 0 A,40to143 B4Oto0 C,0to0 D,0to0 Pebble Count 140 120 100 E N 80 in 60 f6 IL 40 20 0 Pebble Count Statistics (zoom) Max d84 d16 Min • d50 + MaxMob 15 t13 7 A,40to143 B4Oto0 C,0to0 D,0to0 Pebble Count Seg 11 Site 19.123 02/06/02 Segment 11, Site No.19 Cross Section No. 26, at River Mile 14.012 Pebble Count A 100% 5 90% 80% c 70% m L 60% C C LZ 50% G u 40% N 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count 8 100% 90% 80% C 70% m L 60% Ql C u. 50% c v 40% 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% c 70% m L 60% N C E 50% C I 40% N d 30% 20% 10% I 0% 1 10 100 1000 Particle Size (mm) Seg 1 1 S i to 19.123 02/06/02 RM 14.012, Segment 11, Site 19 MEN MEE- JR WOM RAI MR EM-ME 0 XA ENE OREWMEME EENM�IIMMEEMMEM INEWMEM MEMENEMMOMMENE MEN MUNSWEE ENIMMENEEMEMEM WEEMME ONME MEMMEMERIUMEMEMEMEWIRI ME MENNEN■EMEMMMEEMNIMMEMMW.■ MEMMEMEMEMEM■MOMEMIMMENEW EFff'Affla NO moll MENEM Cedar River Gravel Study Data Summary for Site No.20, Cross Section No. 18m, Located in Segment 11 at River Mile 13.208 Segment Summary Segment 11 is 1.926 miles long, extending from RM 14.064 to RM 12.138. It is generally described as: Bends, levees, variable confinement. Average gradient is estimated to be 0.47. Known local sediment sources are: Taylor Creek at RM 13.4 (limited fine sed only); unnamed creek at RM 12.6; 25 ft high banks at RM 12.5; Webster lake drainage at RM 12.2. Data collected during this study include: Sites 19-21; pebble counts on unnamed creek and Taylor Cr [?]. Other studies active in this segment include: None. Subsegment Summary Description: Estimated at 115 ft u/s of King Co flood study xs 18; surveyed 492 ftd/s of xs 19; RB confined by levee u/s only —levee ends at xs; natural front on LB, but then drops back down to old meander cutoff channel --this channel rejoins mainstem on LB d/s of xs Widths and Depths Surveyed Width (ft) 118.4 BF Width (ft) 96.3 BF Depth (ft) 3.42 Width/Depth Ratio (ft/ft) 28.2 Bed Width (ft) 82.4 Active Width (ft) 82.4 Active Depth (ft) 1.01 Confinement and Banks 10 yr Width (ft) 205.0 10 yrBF Ratio 2.13 BF Elevation (ft, datum) 257.7 10 yr Elevation (ft, datum) 260.94 LB RB Est % Levee 80 100 Est % Revetment 0 0 Bank Ht, Typical (ft) 4.5 11 Bank Ht, Max (ft) 5 13 Material Source alluvial levee fill Dom/Subdom Size nd nip p Bank Size Relative to Bed 25-75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Glide Secondary Habitat Types Riffle Gross Spawn Area (sq. ft.) 15744 Percent Usable 50 ASA (sq. ft.) 7872 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment 6 adult sockeye Fish Observed, adj. Segment Gradients Survey Length (ft) 192.0 Water Surface Slope (ft/ft 0.0094 Avg Bed Slope (ft/ft) 0.0057 L25 Bed Slope (ftfft) 0.0116 M50 Bed Slope (ftfft) 0.0074 R75 Bed Slope (ft/ft) -0.0020 Geomorphology Bed Morphology Plane bed Channel Pattern Single' Subsegment I Adj. Segment Gravel Bar Type Point None Bar Material Gr Typ. Bar Width (ft) 65 Max. Bar Width (ft) 75 Max. Bar Width (cw) 0.8 Bar Vegetation Encroaching vegetation Fine Sediment In Riffles Local, sheltered locations In Pools N/A Cobble Embeddedness 15-35% Notes, Comments 'Meander cut-off channel on LB could make this a multiple channel segment (instead of single), but much of fhe segment has levees Q =108 at Landsburg Below Div. Datum: NAVD88 Bankfull Confidence: nd (probably low) Bankfull Indicators: nd (??? because end of levee at RB; meander cutoff channel on LB) ASA Deductions: estimated 60% of area, then less —10% for excess fines and compaction Pebble Counts ID A B C D Method Count Visual None None Cross Section Location 122 to 82 141 to 122 0 to 0 0 too Sizes (mm) Maximum mobile 205 nd nd nd Maximum 161 161 nd nd d84 81 81 nd nd d50 41 70 nd nd d16 20.5 28.5 nd nd Minimum 0.10 20.50 nd nd Segl l Site20.123 02/06/02 Segment 11, Site No.20 Cross Section No. 18m, at River Mile 13.208 Channel Cross Section Bankfull Width = 96.3 ft.; Bankfull Depth = 3.42 ft. CO261 m 260 0 z 259 258 L F m 257 Rf F 256 B 255 0 > 254 a w 253 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 82.4 ft.; Active Width = 82.4 ft.; Active Depth = 1.01 ft. 261 CO ao 260 0 z 259 E 258 L F is !2, 257 R F 256 C 255 — — — — — — — — — — — — — — — — — 0 > 254 P a� w 253 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0094 and Avg Bed Gradient = 0.0057 256 ao z 255 E 3 m 254 a� w or- 253 CD w 252 110 90 70 50 30 10 -10 -30 -50 -70 -90 -110 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) i BedEl L + Bed El M -A- BedEl R +- WaterSurface y ti Seg 11 Site20.123 02/06/02 Segment 11, Site No.20 Cross Section No. 18m, at River Mile 13.208 Pebble Count Statistics 220 200 4205 180 160 140 Max E d84 N 120 d16 in Min m 100 m• d50 80 o_ • MaxMob 60 40 -41 20 0 A, 122 to 82 B, 141 to 122 C, 0 to 0 D, 0 to 0 Pebble Count Pebble Count Statistics (zoom) 120 205 110 100 90 80 841 Max E d84 NO N �0 d16 i'n 60 Min m 50 • d50 40 ' •__ MaxMob 30 20 10 0 A, 122 to 82 B, 141 to 122 C, 0 to 0 D, 0 to 0 Pebble Count Seg 11 Site20.123 02/06/02 Segment 11, Site No.20 Cross Section No. 18m, at River Mile 13.208 Pebble Count A 100% 16 90% 80% c 70% m L 60% C 4 u_ 50% C u 40% N 30% 20% 10% i 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% I 90% 80% c 70% m L ~ 60% `m C L 50% C u 40% aU a 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% c 70% m L 60% C 1Z 50% c 40% a`) a 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Seg11 Site20.123 02/06/02 Cedar River Gravel Study Data Summary for Site No.21, Cross Section No. 13, Located in Segment 11 at River Mile 12.666 Segment Summary Segment 11 is 1.926 miles long, extending from RM 14.064 to RM 12.138. It is generally described as: Bends, levees, variable confinement. Average gradient is estimated to be 0.47. Known local sediment sources are: Taylor Creek at RM 13.4 (limited fine sed only); unnamed creek at RM 12.6; 25 ft high banks at RM 12.5; Webster lake drainage at RM 12.2. Data collected during this study include: Sites 19-21; pebble counts on unnamed creek and Taylor Cr [?]. Other studies active in this segment include: None. Subsegment Summary Description: —6' upstream[?] of flood study cross-section 13, but could not find red cap rebar BM. Widths and Depths Surveyed Width (ft) 126.5 BF Width (ft) 83.8 BF Bed Width Active Confinement and Banks 27.5 66.01 10 yr Width (ft) 540.0 10 yrBF Ratio 6.44 BF Elevation ft, datum 95.1 10 yr Elevation ft, datum 248.65 LB RB Est. % Levee 0 0 Est. % Revetment 0 0 Bank Ht., Typical ft 4 4 Bank HL, Max (ft) 4 4 Material Source alluvial alluvial Dom/Subdom Size Cob/Gr Cob/Gr Bank Size Relative to Bed 25-75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types Gross Spawn Area sq. ft.) 11088 Percent Usable 35 ASA (sq. ft.) 3880.8 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment —24 adult sockeye Fish Observed, adj. Segment Gradients Survey Length (ft) 168.0 Water Surface Slope ft/ft 0.0056 Avg Bed Slope (ft/ft) 0.0141 L25 Bed Slope (ft/ft) 0.0108 M50 Bed Slope ft/ft 0.0141 R75 Bed Slope ft/ft) 0.0173 Geomoroholoov Bed Morphology Plane bed Channel Pattern Single Subsegment I Adj. Segment Gravel Bar Type Lateral None Bar Material S.Cob/L.Cob Typ. Bar Width (ft) 37 Max. Bar Width (ft) 40 Max. Bar Width cw 0.5 Bar Vegetation Encroaching vegetation Fine Sediment In Riffles Local, sheltered locations In Pools N/A Cobble Embeddedness <15% Notes. Comments Upstream area of study site is steep/fast riffle, downstream is slow riffle. Pebble count B is visual estimate of deep thalweg portion of channel; added 4 ft on RB to Peb Count A since similar sized material Q =108 at Landsburg Below Div. Datum: Relative Bankfull Confidence: nd Bankfull Indicators: nd ASA Deductions: high velocity in upstream riffle and large substrate Pehhle Counts ID A B C D Method Count Visual None None Cross Section Location 93 to 149 118 to 145 0 to 0 0 to 0 Sizes (mm) Maximum mobile 205 nd nd nd Maximum 225 250 nd nd d84 113 161 nd nd d50 81 110 nd nd d16 56.5 40.5 nd nd Minimum 20.50 29.00 nd nd Seg 11 Site21.123 02/06/02 Segment 11, Site No.21 Cross Section No. 13, at River Mile 12.666 Channel Cross Section Bankfull Width = 83.8 ft.; Bankfull Depth = 3.05 ft. 99 r>— 98 97 E 96 95 0 94 a) R tE 93 — — — — — — — c cc 91 a>, w 90 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 66.0 ft.; Active Width = 66.0 ft.; Active Depth = 0.88 ft. 99 a ) 2 98 m ,a' 97 E 96 2 0 95 94 a) tE 93 —PC------ P c 92 PC CC,1)) 91 w 90 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0056 and Avg Bed Gradient = 0.0141 95 a) cc 94 cc E 93 F-- �'—_ 0 92 --- ---_ 91 o —— 90 — — Ul w 89 100 80 60 40 20 0 -20 -40 -60 -80 -100 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) f BedEl L a BedEl M i BedEl R +, WaterSurface Seg11 Site21.123 02/06/02 Segment 11, Site No.21 Cross Section No. 13, at River Mile 12.666 260 240 220 200 180 160 F 140 ID 120 m 100 a- 80 60 40 20 0 Pebble Count Statistics Max d84 d16 Min • d50 • MaxMob Il 61 A, 93 to 149 B, 118 to 145 C, 0 to 0 D, 0 to 0 Pebble Count Pebble Count Statistics (zoom) 180 os 160 61 140 120 Max 3 d84 N 100 d16 in Min a) 80 • d50 n 60 • MaxMob 40 20 0 A, 93 to 149 B, 118 to 145 C, 0 to 0 D, 0 to 0 Pebble Count Seg 11 Site21.123 02/06/02 Segment 11, Site No.21 Cross Section No. 13, at River Mile 12.666 Pebble Count A 100% 5 90% 80% 70% m L 60% C ii 50% c 2 40% 57 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% 90% 80% c 70% m L 60% Q) ii 50% c 40% v d 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% C 70% m L 60% `m ii 50% c 40% 2 IL 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) S eg 11 S i te21.123 02/06/02 Tally 0 0 0 0 0 0 0 1 5 12 8 7 15 10 6 2 3 0 3 2 30 104 Unnamed Creek Pebble Count Tributary to Mainstem Segment No. 11 at River Mile 12.605 Nearest Downstream Study Site: Segment 11, Site 22 at River Mile 12.054 Particle Size Bedrock VL Boulder; 2049-4096 L Boulders 1025-2048 M Boulders 513-1024 S Boulders 385-512 S Boulders 257-384 L Cobbles 193-256 L Cobbles 129-192 S Cobbles 97-128 S Cobbles 65-96 VC Gravel 49-64 VC Gravel 33-48 C Gravel 25-32 C Gravel 17-24 M Gravel 13-16 M Gravel 9-12 F Gravel 7-8 F Gravel 5-6 VF Gravel 3-4 Sand 1-2 Sa/Si/CI <1 Pct Dist Cum Dist 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 1.0% 100% 4.8% 99% 11.5% 94% 7.7% 83% 6.7% 75% 14.4% 68% 9.6% 54% 5.8% 44% 1.9% 38% 2.9% 37% 0.0% 34% 2.9% 34% 1.9% 31 % 28.8% 29% 180 170 160 150 140 130 120 E 110 N 100 90 80 U m 70 60 50 40 30 20 10 0 Pebble Count Statistics Max d84 d16 Min • d50 Pebble Count Unnamed Creek Pebble Count 100% 1 16 90% 80% s 70% 60% iL 21 c 50% (W U d 40% 30% 20% 10% 1 10 100 1000 Particle Size (mm) Notes: Additional sample collected by Jones & Stokes on 9/5/01 Taylor Cr. is —800' D/S of Site No. 21 (Seg. 11). Pebble Count taken —100' U/S from confluence with Cedar R. Seg 11 Taylor Creek.123 02/06/02 Cedar River Gravel Study Data Summary for Site No.22, Cross Section No. 9m, Located in Segment 12 at River Mile 12.054 Segment Summary Segment 12 is 0.449 miles long, extending from RM 12.138 to RM 11.689. It is generally described as: Lion's Club unconfined, flat. Average gradient is estimated to be 0.33. Known local sediment sources are: 1996 landslide, 125 ft high cliffs, revegetated at RM 11.9. Data collected during this study include: Site 22. Other studies active in this segment include: USFWS. Subsegment Summary Description: 270 ft d/s of approximate location of flood study cross-section 9 (per survey notes); current location is thought to coincide with location of USFWS xs (R. Peters) Widths and Depths Surveyed Width (ft) 110.4 BF Width (ft) 81.5 BF Depth (ft) 3.78 Width/Depth Ratio (ft/ft) 21.6 Bed Width ft 66.6 Active Width ft 71.2 Active Depth ft 1.14 Confinement and Banks 10 yr Width ft 1550.0 10 /BF Ratio 19.02 BF Elevation ft, datum) 98.6 10 yr Elevation ft, datum 236.63 LB RB Est % Levee 0 0 Est % Revetment 100 0 Bank Ht., Typical (ft) 4 6 Bank Ht., Max (ft) 10 slope contin Material Source Riprap alluvial Dom/Subdom Size Riprap Gr/Cob Bank Size Relative to Bed 25-75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Glide Secondary Habitat Types Gross Spawn Areas . ft. 11534 Percent Usable 75 ASA (sq. ft. 8650.5 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment Fish Observed, adj. Segment Gradients Survey Length (ft) 164.0 Water Surface Slope ft/ft 0.0003 Avg Bed Slope ft/ft) -0.0018 L25 Bed Slope (ft/ft) -0.0118 M50 Bed Slope ft/ft 0.0003 R75 Bed Slope (ft/ft) 0.0060 Geomo hology Bed Morphology Plane bed Channel Pattern Single Subsegment Adj. Segment Gravel Bar Type None None Bar Material Typ. Bar Width (ft) Max. Bar Width ft Max. Bar Width cw Bar Vegetation es up Fine Sediment In Riffles Local, sheltered locations In Pools N/A Cobble Embeddedness 15-35% Notes, Comments Red flagged rebar on xs at LB pre-existed this survey and is thought to be USFWS (Peters) SM Q = 114 at Landsburg Below Div. Datum: Relative Bankfull Confidence: Mod Bankfull Indicators: Slope break on RB; nd for LB ASA Deductions: subtract channel margins only Pebble Counts ID A B C D Method Count Visual Visual Visual Cross Section Location 103 to 61 61 to 47 47 to 42 116 to 103 Sizes mm Maximum mobile 130 nd nd nd Maximum 161 113 4 16 d84 57 81 4 15 d50 29 57 2 4 d16 14.5 20.5 0.5 0.5 Minimum 0.10 1.00 0.50 0.50 SEGI2SITE22.123 03/14/02 Segment 12, Site No.22 Cross Section No. 9m, at River Mile 12.054 Channel Cross Section Bankfull Width = 81.5 ft.; Bankfull Depth = 3.78 ft. 102 m —> 101 00 100 99 R 0 98 97 d---------------- RR 96 c 95 cc L B 94 w 93 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 66.6 ft.; Active Width = 71.2 ft.; Active Depth = 1.14 ft. 102 m tv 101 100 99 R YF tj 98 p v 97 — — — — — — — — — — — — — — — — �°' 96 c 0 95 E > C a2 94 w 93 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0003 and Avg Bed Gradient =-0.0018 97 a� a� IX 96 E m 95 d w c 94 ■ SEGI2SITE22.123 03/14/02 Segment 12, Site No.22 Cross Section No. 9m, at River Mile 12.054 160 140 120 100 N m 80 V 60 40 20 0 Pebble Count Statistics Max d84 d16 Min d50 • MaxMob Z 57 7 29 15 A, 103 to 61 B, 61 to 47 C, 47 to 42 D, 116 to 103 Pebble Count Pebble Count Statistics (zoom) 130 80 E60 Max d84 57 7 N Un d16 Min 40 V `° o_ • d50 • MaxMob -29 20 15 0 F--, 4 A, 103 to 61 B, 61 to 47 C, 47 to 42 D, 116 to 103 Pebble Count SEGI2SITE22.123 03/14/02 Segment 12, Site No.22 Cross Section No. 9m, at River Mile 12.054 Pebble Count A 100% 16 90% 80% c 70% M L 60% 50% Z C u 40% N a 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% 90% 80% c 70% m L 60% N C z 50% c u 40% m 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% C 70% m L 60% N C u 50% C u 40% N 0 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) SEG12SITE22.123 03114i02 7E ■■■■■■■ ■■■■■■■■■o■ ■■� ■■■■■ ■■■■■■■■■ ■■■■■■■■■■■ MEN ■! ■e ■■►/■■■■■■■■■ ■ ■■■■■ an ■■■■■rP■■■■■■ ■ ■ ■ ■■■ !w■�■A1 �:■�.�■ ■ ■■MAN !■on � ■■■■I m g No on WHOM ���■ r� Gar-� �J'i�i.�JG. •►�1.+71 .. A 1 ■■■,�� �� I� ■■ ■�■AI Aon ■ ■ ��. ■I■■■ i}�■i► ■ ■■■■■■Ois■1 i�■M ■ .�■� I■ jk , ■ ■■■MMES �m on �► • MMM ■ ■■■■ ■ �■■■r�■■■■ am ■■m■ ■ ■■ ■ ■■ ■ ■ ■■■■■�i►, r■■■ ■ ■■■■r �� ■■ ■ ■■ ■■ ■ ■■■■■!�■ ■ ■■■■■ ■ IN ■■■ ■■ ■■■■ ■■■■■■G7■■■■■■■■ ■ ■■ ■ ■■ 0 c;. Cedar River Gravel Study Data Summary for Site No.23, Cross Section No. 2m, Located in Segment 13 at River Mile 11.366 Segment Summary Segment 13 is 0.677 miles long, extending from RM 11.689 to RM 11.012. It is generally described as: Cedar Grove, floods despite levees. Average gradient is estimated to be 0.44. Known local sediment sources are: Cedar Hills tributary (limited fine sed only) at RM 11.6. Data collected during this study include: Site 23. Other studies active in this segment include: None. Subsegment Summary Description: Located 156 ft d/s of flood study cross-section 2; moved d/s to accommodate better spawning gravel Widths and Depths Surveyed Width (ft) 121.0 BF Width (ft) 100.8 BF Depth (ft) 1.80 Width/Depth Ratio (fttft) 55.9 Bed Width (ft) 95.9 Active Width (ft) 95.9 Active Depth (ft) 0.54 Confinement and Banks 10 yr Width (ft) 770 10 /BF Ratio 7.64 BF Elevation (ft, datum) 219.5 10yr Elevation (ft, datum) 224.54 LB RB Est. % Levee 0 Est. % Revetment 0 40 Bank Ht, Typical (ft) 4 5 Bank Ht., Max (ft) 5 7 Material Source alluvial Riprap Dom/Subdom Size Gr Riprap Bank Size Relative to Bed 25-75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Glide Secondary Habitat Types Riffle Gross Spawn Area (sq. ft.) 19296 Percent Usable 85 ASA (sq. ft.) 16401.6 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment 1 6" trout Fish Observed, adj. Segment Gradients Survey Length (ft) 200.0 Water Surface Slope (ft/ft; 0.0021 Avg Bed Slope (ft/ft) -0.0042 L25 Bed Slope (ft/ft) 0.0007 M50 Bed Slope (ft/ft) -0.0028 R75 Bed Slope (ft/ft) -0.0106 Geomoroholoav Bed Morphology Plane bed Channel Pattern Single Subsegment I Adj. Segment Gravel Bar Type Lateral Bar Material Coarse gr. Typ. Bar Width (ft) 20 Max. Bar Width (ft) Max. Bar Width (cw) Bar Vegetation 30 0.3 Bare of vegetation Fine Sediment In Riffles Local, sheltered locations In Pools N/A Cobble Embeddedness 15-35% Nntac rnmmants LB floodplain is former house site(s) recently reclaimed by King Co with riparian plantings of willow, cottonwood, maple. Easy access from Cedar Grove Rd _ Q = 138 at Renton Pebble Counts slope break and veg breaks clear ID A B C D Method Count None None None Cross Section Location 150 to 54 0 to 0 0 to 0 0 to 0 Sizes (mm) Maximum mobile 260 nd nd nd Maximum 161 nd nd nd d84 81 nd nd nd d50 41 nd nd nd d16 20.5 nd nd nd Minimum 0.10 nd nd nd Seg 13Site23.123 02/06/02 Segment 13, Site No.23 Cross Section No. 2m, at River Mile 11.366 Channel Cross Section Bankfull Width = 100.8 ft.; Bankfull Depth = 1.80 ft. 223 - 00 11 222 4z 221 E 220 0 R 219 LB---------------------RB 218 0 217 T d w 216 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 95.9 ft.; Active Width = 95.9 ft.; Active Depth = 0.54 ft. 223 CO co j 222 Q z 221 E 0 220 R 219 C— — — — — — — — — — — — — — — — — — — — c 218 0 T > 217 ro w 216 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0021 and Avg Bed Gradient =-0.0042 219 CO 0 Q 218 2 217 m m 216 w , . c ° 215 _ M t 0 w 214 110 90 70 50 30 10 -10 -30 -50 -70 -90 -110 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) ■ BedEl L + BedEl M -A- BedEl R -A� WaterSurface Segl3Site23.123 02/06/02 Segment 13, Site No.23 Cross Section No. 2m, at River Mile 11.366 Pebble Count Statistics 280 0260 240 220 - 200 E 180 m 160 N in 140 120 m 100 a 80 —81 60 40 20 0 A,150to54 B4Oto0 C,0to0 D,0to0 Pebble Count Max d84 d16 Min • d50 • MaxMob Pebble Count Statistics (zoom) 140 260 120 100 E Max E d84 N 80 d16 Un Min 60 • d50 M • MaxMob 40 20 0 A,150to54 B4Oto0 C,0to0 D,0to0 Pebble Count Seg 13Site23.123 02/06/02 Segment 13, Site No.23 Cross Section No. 2m, at River Mile 11.366 Pebble Count A 100% 16 90% 80% c 70% t 4 60% m c ii 50% c (U 40% `m n' 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% 90% 80% c 70% m L 60% N C i 50% c 40% d 30% 20% 10% I 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% I 80% c 70% m 60% ro i� 50% I � I 40% a� d 30% 20% 10% TE 0% 1 10 100 1000 Particle Size (mm) Seg 13Site 23.123 02/06/02 a ■■ ■■■ ■■■■■ ■■■■■■■■■■■■■■■■■ ■Jim ■M ■ ■■■ ■ ■�■■■ ■■■■■■■■■gym■ NE■■■� ■ ■■ ■ ■ ■■ No ■■■■■! MEN ■ONE ■■■ ■■■■ ■■ ■ ■ ■■■ MO ■■■■■■ ■, ON OMEN ■N NNE■ ■M �/1■�a■■■■■ ■M■■■■�■■■ ■■ ■■ ■ ■ M■MNNN■■■ ■■■■� 'MN�w� A l��11■■■A �1■ ■■■ NNNNN NNN MOON \[MBE MI ■■■�' ��l■' M\1o11■N A �A■■!!. ■ ■ ■■ ®ire, N■A ■■■■ ■■ ■N/! N V ��■W i� MEMO �Ni® ■ ®I EZME ■■■■ ■ sM■E ■ ■ ■M ■ i'ii■, _ MOON■■\!®iM' ii ■'M ■ ■ ■ M� ■ .�j�r . EM ■■\1M E®■■■■INN' \.�,,� ..�MM on ;, ■ M■■ �.��..,Ni111\\N■■ ■■■ _ . EMS EE NO■�: M1110MH � • on 0 No O, �1�.. � �► ®■■■r■N■ �� ■NEB N ■\ ■ .: N,�a ■ ■MOON■ ■■ ■7 ', Tally 0 0 0 0 0 0 0 0 0 6 7 29 9 17 14 14 1 2 5 4 2 110 Low Lateral Bench Pebble Count On Mainstem Segment No. 14 at River Mile 10.942 Nearest Study Site: Segment 14, Site 24 at River Mile 10.942 Particle Size Bedrock VL Boulder: 2049-4096 L Boulders 1025-2048 M Boulders 513-1024 S Boulders 385-512 S Boulders 257-384 L Cobbles 193-256 L Cobbles 129-192 S Cobbles 97-128 S Cobbles 65-96 VC Gravel 49-64 VC Gravel 33-48 C Gravel 25-32 C Gravel 17-24 M Gravel 13-16 M Gravel 9-12 F Gravel 7-8 F Gravel 5-6 VF Gravel 3-4 Sand 1-2 Sa/Si/CI <1 Pct Dist Cum Dist 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 5.5% 100% 6.4% 95% 26.4% 88% 8.2% 62% 15.5% 54% 12.7% 38% 12.7% 25% 0.9% 13% 1.8% 12% 4.5% 10% 3.6% 5% 1.8% 2% I N in � 150 140 130 120 110 100 90 80 70 60 50 40Aj 30 20 10 0 Pebble Count Statistics Max d84 d16 Min • d50 • MaxMob Pebble Count Low Lateral Bench Pebble Count 100% t 90% t 80% c 70% CZ L 60% C iL 50% c 40% a� 30% tt 20% TI 10% 0% 1 10 100 1000 Particle Size (mm) Notes: Additional sample collected by Jones & Stokes & Sue Perkins on 09/26/01 Originally intended as a potential subsurface sample site; was inundated at time of visit --surface point count only. This pebble count was limited to a low lateral bench/bar along the RB, with the survey width corresponding approximately to 110 ft to 122 ft on the cross section for Segment 14, Site 24. This bench was a subset of Site 24's Pebble Count A, which extended from 74 ft to 116 ft. Seg14Low Lateral Bench.123 12/04/01 Cedar River Gravel Study Data Summary for Site No.24, Cross Section No. 159, Located in Segment 14 at River Mile 10.942 Segment Summary Segment 14 is 0.786 miles long, extending from RM 11.012 to RM 10.226. It is generally described as: Unconfined bends, 1990 avulsion, LWD jams. Average gradient is estimated to be 0.41. Known local sediment sources are: 50 ft high RB slope at RM 10.6- -unknown if a source. Data collected during this study include: Sites 24-25; low point bar pebble count at Site 24; subsurface sample on point bar d/s Site 25. Other studies active in this segment include: None. Subsegment Summary Description: Flood study xs 159, the upstream of two paired (adjacent) cross -sections in this segment; the low lateral bench on RB included in this pebble count (A), and then again later in a pebble count confined only to this bar Widths and Depths Surveyed Width (ft) 96.0 BF Width (ft) 70.0 BF Depth (ft) 3.81 Width/Depth Ratio (ft/ft) 18.4 Bed Width (ft) 65.0 Active Width (ft) Active Depth (ft) 45.0 1.46 Confinement and Banks 10 yr Width (ft) 840.0 10 yrBF Ratio 12.00 BF Elevation (ft, datum) 210.5 10 yr Elevation (ft, datum) 215.0 LB RB Est % Levee 100 0 Est % Revetment 100 0 Bank Ht, Typical (ft) 9 <2 Bank Ht, Max (ft) 10 <2 Material Source Riprap alluvial . Dom/Subdom Size Mprap Gr/Sa Bank Size Relative to Bed 25-75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types Gross Spawn Area (sq. ft.) 6300 Percent Usable 65 ASA (sq. ft.) 4095 R2 Habitat Type Other Fish Field Fish Observed, in None Subsegment Fish Observed, adj. -20 adult sockeye at Segment upstream right turn @ HWY 169 Gradients Survey Length (ft) 140.0 Water Surface Slope (ft/ft 0.0016 Avg Bed Slope (ft/ft) -0.0025 L25 Bed Slope (ftfft) -0.0057 M50 Bed Slope (ft/ft) -0.0062 R75 Bed Slope (ft/ft) 0.0045 Geomorphology Bed Morphology Plane bed Channel Pattern Single Subsegment Adj. Segment Gravel Bar Type Lateral Bar Material Typ. Bar Width (ft) 20 Max. Bar Width (ft) 23 Max. Bar Width (cw) 0.3 Bar Vegetation Bare of vegetation Fine Sediment In Riffles Local, sheltered locations In Pools N/A Cobble Embeddedness <15% Notes, Comments Q = 138 at Renton IDatum: NAVD88 knotweed but defined slope breaks Pebble Counts ID A B Visual C None D None Method Count Cross Section Location 116 to 74 74 to 59 0 to 0 0 to 0 Sizes (mm) Maximum mobile 167 320 nd nd Maximum 161 320 nd nd d84 81 240 nd nd d50 29 120 nd nd d 16 10.5 100.0 nd nd Minimum 0.10 1.50 nd nd Segl4Site24.123 02/06/02 Segment 14, Site No.24 Cross Section No. 159, at River Mile 10.942 Channel Cross Section Bankfull Width = 70.0 ft.; Bankfull Depth = 3.81 ft. 00 0 100 Q z 98 96 0 RB 94 F m a� 92 c 90 > a� 88 w 86 30 40 50 60 70 80 90 100 110 120 130 140 150 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 65.0 ft.; Active Width = 45.0 ft.; Active Depth = 1.46 ft. CO 0 100 Q z 98 E 96 0 94 CV m 92 0 90 > a� 88 w 86 30 40 50 60 70 80 90 100 110 120 130 140 150 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0016 and Avg Bed Gradient =-0.0025 m 209 0 > 208 z• --- - - - - - - - - - - - - - - - - ---— -- E 207CU ------ 206 ----- 205 - ----� —— ° ——————————————— m 204 — — — — _ — m w 203 80 60 40 20 0 -20 -40 -60 -80 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) f BedEl L 4- BedEl M A, BedEl R ,'� WaterSurface Seg14Site24.123 02/06/02 Segment 14, Site No.24 Cross Section No. 159, at River Mile 10.942 340 320 300 280 260 240 E 220 200 N 180 160 140 d 120 100 80 60 40 20 0 Pebble Count Statistics 20 - - -- - - - - - - - - - 01 0- -- Max d84 d16 Min • d50 MaxMob 0• 81 - A,116to74 B,74to59 C,0to0 D,0to0 Pebble Count 240 220 200 180 160 E N 140 a� 120 r 100 a- 80 60 40 20 0 Pebble Count Statistics (zoom) Max d84 d16 Min • d50 • MaxMob 0 -- - 020 9- - A,116to74 B,74to59 C,0to0 D,0to0 Pebble Count Seg 14Site24.123 02/06/02 Segment 14, Site No.24 Cross Section No. 159, at River Mile 10.942 Pebble Count A 100% 16 90% 1 80% c 70% m L F- 60% N ii 50% 2 C 40% N a 30% 20% 10% 0% 7T� 1 10 100 1000 Particle Size (mm) Pebble Count B 100% 90% 80% c 70% m L 60% N ii 50% c a) 40% a� d 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% i 80% C 70% co L F- 60% N C 50% C 40% N n 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Seg 14S ite24.123 02/06/02 a 0 4e, R Cedar River Gravel Study Data Summary for Site No.25, Cross Section No. 158, Located in Segment 14 at River Mile '10.865 Segment Summary Segment 14 is 0.786 miles long, extending from RM 11.012 to RM 10.226. It is generally described as: Unconfined bends, 1990 avulsion, LWD jams. Average gradient is estimated to be 0.41. Known local sediment sources are: 50 ft high RB slope at RM 10.6 --unknown if a source. Data collected during this study include: Sites 24-25; low point bar pebble count at Site 24: subsurface sample on point bar d/s Site 25. Other studies active in this segment include: None. Subsegment Summary Description: Flood study cross-section 158 (notes); the d/s of two paired (adjacent) sites in this segment Widths and Depths Surveyed Width (ft) 144.0 BF Width (ft) 92.2 BF Depth ft 3.92 W idth/Depth Ratio (fUft) 23.5 Bed Width (ft) 79.6 Active Width (ft) 82.9 Active Depth (ft) 1.12 Confinement and Banks 10 yr Width ft 750.0 10 BF Ratio 8.13 BF Elevation ft, datum) 211.3 10 Elevation ft, datum 213.6 LB RB Est. % Levee 100 0 Est. % Revetment 100 0 Bank Ht., Typical (ft) 8 3 Bank Ht., Max (ft) 8 3 Material Source Riprap alluvial Dom/Subdom Size Gr/Sa Ripra Bank Size Relative to Bed 25-75% < c s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Glide Seoondary Habitat Types Gross Spawn Area . ft.) 15305 Percent Usable 70 ASA sq. ft. 10713.5 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment 1, 4" sculpin Fish Observed, adj. Segment Gradients Survey Length (ft) 184.0 Water Surface Slope ft/ft 0.0012 Avg Bed Slope ft/ft -0.0029 L25 Bed Slope ftfft) -0.0011 M50 Bed Slope ft/ft 0.0027 R75 Bed Slope ft/ft -0.0102 Goomorphology Bed Morphology Plane bed Channel Pattern Single Subsegment Adj. Segment Gravel Bar Type None Lateral Bar Material Typ. Bar Width (ft) Max Bar Width ft Max. Bar Width cw Bar Vegetation Fine Sediment In Riffles Local, sheltered locations In Pools N/A Cobble Embeddedness <15% Notes, Comments Q =138 at Renton Datum: NAVD88 Bankfull Confidence: Low Bankfull Indicators: Steep levee & riprap on LB; broken topography, including small alcove pool, on RB ASA Deductions: large substrate in left channel margin Pebble Counts ID A B C D Method Count None None None Cross Section Location 46 to 125 0 to 0 0 to 0 0 to 0 Sizes mm Maximum mobile 210 nd nd nd Maximum 161 nd nd nd d84 81 nd nd nd d50 57 nd nd nd d16 28.5 nd nd nd Minimum 0.10 nd nd nd Seg 14Site25.123 02/06/02 Segment 14, Site No.25 Cross Section No. 158, at River Mile 10.865 Channel Cross Section Bankfull Width = 92.2 ft.; Bankfull Depth = 3.92 ft. 217 CO 0 216 215 Z. 214 E 213 LF 0212 211 B w 210 c 209 0 'C ----- 208 NR m> 207 w 206 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 79.6 ft.; Active Width = 82.9 ft.; Active Depth = 1.12 ft. 217 CO 00 216 Q 215 Z 214 E 213 .212 r LF 211 w 210 c C 209 0 'C ------ 208 A 207 w 206 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0012 and Avg Bed Gradient =-0.0029 92 0 z 91 0 — — — — — — — — — — — — — — 90 m — 0 89—�— a� w 88 110 90 70 50 30 10 -10 -30 -50 -70 -90 -110 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) 0 BedEl L � BedEI M } BedEl R -A- WaterSurface Seg 14Site25.123 02/06/02 Segment 14, Site No.25 Cross Section No. 158, at River Mile 10.865 Pebble Count Statistics 220 0210 200 180 160 E Max 140 d84 m d16 120 Min 100 • d50 a 80 81 MaxMob 60 40 20 0 A,46to125 B4Oto0 C,0to0 D,0to0 Pebble Count Pebble Count Statistics (zoom) 100 ,o 80 E Max 60 d84 7 N in d16 Min m r 40 • d50 • MaxMob 20 0 A,46to125 B4Oto0 C,0to0 D,0to0 Pebble Count Seg 14Site25.123 02/06/02 Percent Finer Than 08N W A Cn M -1 CA CD O O O O O O O O O O 0 0 0 0 0 o e o 0 0 0 O N C NCD CD Q c N 0 C C 3 3 n O Percent Finer Than C)O O O O O O O O O O e o 0 0 o e e e e e o O CD (D Co C7 N (D 0 C C 3 3 W 0 O O Percent Finer Than N W A 0 0) -I 0o CD O O O O O O O O O O O O O n N C Cn � ^ C 3 3 D O J OI O O n O N N (D _� N O N 7 (o z3 o m 00 ? 00 _ a) CD Cp O � N CD Tally 0 0 0 0 0 0 1 5 10 12 9 35 18 6 3 2 1 0 2 0 2 106 Bar Surface Material Pebble Count On Mainstem Segment No. 14 at River Mile 10.366 Nearest Downstream Study Site: Segment 15, Site 26 at River Mile 10.017 Particle Size Bedrock VL Boulder; 2049-4096 L Boulders 1025-2048 M Boulders 513-1024 S Boulders 385-512 S Boulders 257-384 L Cobbles 193-256 L Cobbles 129-192 S Cobbles 97-128 S Cobbles 65-96 VC Gravel 49-64 VC Gravel 33-48 C Gravel 25-32 C Gravel 17-24 M Gravel 13-16 M Gravel 9-12 F Gravel 7-8 F Gravel 5-6 VF Gravel 3-4 Sand 1-2 Sa/Si/CI <1 Pct Dist Cum Dist 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.0% 100% 0.9% 100% 4.7% 99% 9.4% 94% 11.3% 85% 8.5% 74% 33.0% 65% 17.0% 32% 5.7% 15% 2.8% 9% 1.9% 7% 0.9% 5% 0.0% 4% 1.9% 4% 0.0% 2% 1.9% 2% Pebble Count Statistics 260 240 220 200 180 EMax 160 84 N 140 d16 n Min a> 120 100 • d50 o_ `a • MaxMob 80 60 40 20 0 Pebble Count Bar Surface Material Pebble Count 100% 5 90% 80% .00 c 70% t 1 60% a`) c ii 50% C v 40% o_ 30% 29 20% 10% 0% 1 10 100 1000 Particle Size (mm) Notes: Surface "skin" over subsurface bulk sample collected by Jones & Stokes & Sue Perkins on 09/26/01 Large new bar between flood study cross sections located at RM's 10.337 and 10.394. Bar extends over 100 yards in length; typical width — 30 ft. Sample obtained 1/2 way between u/s end and mid -point of bar, and represents a 15 ft x 15 ft area surrounding the subsurface sample. Seg14Bar Surface Material.123 02/06/02 Cedar River Gravel Study Data Summary for Site No.26, Cross Section No. 150, Located in Segment 15 at River Mile 10.017 Segment Summary Segment 15 is 0.601 miles long, extending from RM 10.226 to RM 9.625. It is generally described as: Moderately confined, bedrock bends, flatter. Average gradient is estimated to be 0.34. Known local sediment sources are: 75 ft high RB slope at RM 10.1 -unknown if a source. Data collected during this study include: Site 26. Other studies active in this segment include: None. Subsegment Summary Description: -30' upstream of flood study cross-section 150; immediately d/s of LB side channel return to mainstem Widths and Depths Surveyed Width (ft) 133.0 BF Width (ft) 100.0 BF Depth (ft) 2.02 Width/Depth Ratio (f 1ft) 49.5 Bed Width (ft) 83.3 Active Width (ft) 83.3 Active Depth (ft) 0.56 Confinement and Banks 10 yr Width (ft) 310.0 10 yr/BF Ratio 3.10 BF Elevation (ft, datum) 97.1 10 yr Elevation (ft, datum) 198.16 LB RB Est. % Levee 0 0 Est. % Revetment 0 0 Bank Ht., Typical (ft) 5 2 Bank Ht., Max (ft) 6 4 Material Source alluv/levee alluvial Dom/Subdom Size Gr/Cob Gr/Cob Bank Size Relative to Bed >75% < c.s. Bank Erosion Outside bends Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types None Gross Spawn Area (sq. ft.) 16600 Percent Usable 30 ASA (sq. ft.) 4980 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment 5, 3" juvenile salmonids Fish Observed, adj. Segment Gradients Survey Length (ft) 200.0 Water Surface Slope (ft/ft; 0.0031 Avg Bed Slope (ft/ft) 0.0070 L25 Bed Slope (ft/ft) 0.0128 M50 Bed Slope (ft/ft) 0.0066 R75 Bed Slope (ft/ft) 0.0014 Geomorphology Bed Morphology Plane bed Channel Pattern Multiple Subsegment Adj. Segment Gravel Bar Type Medial Lateral Bar Material Typ. Bar Width (ft) 50.0 25.0 Max. Bar Width (ft) 60.0 30.0 Max. Bar Width (cw) 0.6 0.3 Bar Vegetation Encroaching vegetation Established vegetation Fine Sediment In Riffles Local, sheltered locations In Pools N/A Cobble Embeddedness <15% Notes, Comments "Adj. Segment" gravel bar is on RB below cross-section. LB is a natural terrace. Steep slope on RB upstream of transect. Side channel immediately u/s of xs on LB has separate visual peb cnt. Q = 216 at Renton Datum: Relative Bankfull Confidence: Low Bankfull Indicators: On RB low veg bar extends into shrubs to Thigh terrace - hard to define BF. LB = natural levee cut bank. ASA Deductions: high velocity, large substrate Side channel length est @ 30% of mainstem length in this segment. Pebble Counts ID A B C D Method Count Visual None None Cross Section Location 137 to 54 Side Channel 0 to 0 0 to 0 Sizes (mm) Maximum mobile 260 nd nd nd Maximum 321 260 nd nd d84 161 80 nd nd d50 81 35 nd nd d 16 40.5 5.5 nd nd Minimum 0.10 0.50 nd nd Seg15Site26.123 02/06/02 Segment 15, Site No.26 Cross Section No. 150, at River Mile 10.017 Channel Cross Section Bankfull Width = 100.0 ft.; Bankfull Depth = 2.02 ft. .� 102 d 101 d x 100 E 99 is 98 0 97RRZ c 96 RR — — — — — — — — — — — — — — — _>> 95 T w 94 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 83.3 ft.; Active Width = 83.3 ft.; Active Depth = 0.56 ft. 102 m = cc 101 M 100 E 99 0 98 RR .T 97 ---------------� m 95 T w 94 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0031 and Avg Bed Gradient = 0.0070 m 97 m 96 E 95 a� c 94 0 > a� w 93 110 90 70 50 30 10 -10 -30 -50 -70 .90 -110 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) ■ BedEl L * Bed El M -& Bed El R -+- WaterSurface y Seg15Site26.123 02/06/02 Segment 15, Site No.26 Cross Section No. 150, at River Mile 10.017 Pebble Count Statistics 340 320 300 280 260 240 E 220 200 a� N 180 160 -161 a� 140 a 120 100 80 61 8 60 40 20 0 A, 137 to 54 Side Channel C, 0 to 0 D, 0 to 0 Pebble Count Max d84 d16 Min • d50 • MaxMob 180 160 140 120 E N 100 in 76 80 a 60 40 20 0 Pebble Count Statistics (zoom) Max d84 d16 Min • d50 • MaxMob 260 8 1315 A, 137 to 54 Side Channel C, 0 to 0 D, 0 to 0 Pebble Count Seg 15Site26.123 02/06/02 Segment 15, Site No.26 Cross Section No. 150, at River Mile 10.017 Pebble Count A 100% 32 61 90% 80% c 70% m L ~ 60% c 81 ii 50% c 2 40% a 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count 8 100% 90% 80% C 70% CO L 60% N c 50% c 2 40% Q) 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% c 70%t7 m L 60% N C i 50% C I U 40% a 30% 20% 10% I 0% 1 10 100 1000 Particle Size (mm) Segl5Site26.123 02,106/02 �' h �M — -=y. rC YJ(/►,�„/ D �-► � � j p� � �i fir° +ick, �� l "� 2 0" f g1oh V, / l �2 DID Co+�� wa$(rst ih ■■ ■■■■■■■■■■I■■■■■■■■11■I■■■■�i►■■R■■■■■■■■ILO■�! . ■ ■m■■■■■■ummu■■s■■ ,■ �M� M'6'Ja■rsp Son ■ ■ ■■Mill ■■■Immmm Imimm �■m■■■■■l■■ M �� r■■■��■too■■■■ ■n ili�i■� ■ wadmm■■mmm ■■■■A .�■E �►,�i/ ; ^1�,i�■iC ■ mmm mle 1 ■ ■l■�� ■u■■ . ■� ■m■■ WHIZZ04 ■■■■■■ fl■■■■1/loll ■ ■■■' ®■®■■■ ■■■'r■ ■i .■■■i■■■o fl mmolollimol■■■llr ■ ■l ■ ■■■ ■. ■■ E■■■m■■■II none lm �■■ . r on on on 1■■ O■■■■IN 11 a ■N m i 0 ME ME ME 0 5101 on ION NN ON I I mumm on no ■o ■■ ■�■■■ ■■ ■© ■ MEN ON 0 ■■ ■ _ ■ ■■ ■mm lei INN on WIN IN on mll �7 0 =m=mFmm Pa ��WON*- � ffimpl. - 1,. 9-Mamal l �i VITI SOREN noun - -� mr M E G P. Cm ml-� rK SKI ■l mll mormf my ram■�t�Ral ■■m ■■■■ ■■ INN■� ■■■■ l NONE ■ !�■m o■l'iii��1�i�;!, who on ■ ■ loll mommlm®■ No ■■ ■ ■I�iWiilN■®�i■gloom 0 0 !on■■ ■ ■■ �" m/�1GIfts lWIN oll■■ ■■' m loll■ i IPi Cedar River Gravel Study Data Summary for Site No.27, Cross Section No. 141, Located in Segment 16 at River Mile 9.252 Segment Summary Segment 16 is 2.931 miles long, extending from RM 9.625 to RM 6.694. It is generally described as: Jones Road, mostly confined. Average gradient is estimated to be 0.44. Known local sediment sources are: Mid-80s Lake McDonald gully, 100 ft high RB slope at RM 9.6—unknown if a source. Data collected during this study include: Sites 27-29. Other studies active in this segment include: USFWS. Subsegment Summary Description: Flood study cross-section 141 (notes) Widths and Depths Surveyed Width (ft) BF Width (ft) BF Depth (ft) 132.0 115.7 2.37 Width/Depth Ratio (ft/ft) 48.9 _ Bed Width (ft) 110.2 Active Width (ft) 110.2 Active Depth (ft) 0.78 Confinement and Banks 10 yr Width (ft) 160.0 10 /BF Ratio 1.38 BF Elevation (ft, datum) 97.5 10 yr Elevation (ft, datum) 184.33 LB RB Est. % Levee 0 0 Est. % Revetment 0 0 Bank Ht., Typical ft 2 4 Bank Ht., Max (ft) 4 6 Material Source alluvial alluvial Dom/Subdom Size Gr/Cob/Sa Gr/Cob/Sa Bank Size Relative to Bed 25-75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types Pool Gross Spawn Area (sq. ft.) 25300 Percent Usable 40 ASA (sq. ft.) 10120 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment —0.5"-2" juviniles/fry?, —6 Fish Observed, adj. Segment Gradients Survey Length (ft) 230.0 Water Surface Slope (ft/ft; 0.0028 Avg Bed Slope (ft/ft) -0.0011 L25 Bed Slope (ft/ft) 0.0048 M50 Bed Slope (ft/ft) -0.0011 R75 Bed Slope (fVft) -0.0070 Geomorphology Bed Morphology Plane bed Channel Pattern Multiple Subsegment Adj. Segment Gravel Bar Type Medial Medial Bar Material Typ. Bar Width (ft) 25 Max. Bar Width (ft) 30 Max. Bar Width (cw) 0.3 Bar Vegetation Encroaching vegetation Fine Sediment In Riffles Local, sheltered locations In Pools Patches + local Cobble Embeddedness <15% Notes, Comments Small medial gravel bar just upstream of study segment. Q = 216 at Renton Datum: Relative Bankfull Confidence: nd BankfullIndicators: nd ASA Deductions: Backwater pool behind bar, 50% of fast riffle on RB unavailable due to packed bed and larger substrate. Pebble Counts ID A B C D Method Count Count Visual None Cross Section Location 78 to 96 96 to 146 1 40 to 78 0 to 0 Sizes (mm) Maximum mobile 160 250 172 nd Maximum 161 225 172 nd d84 57 113 100 nd d50 41 57 40 nd d16 20.5 5.5 30.0 nd Minimum 0.10 0.10 0.50 nd Seg 16Site27.123 02/06/02 Segment 16, Site No.27 Cross Section No. 141, at River Mile 9.252 Channel Cross Section Bankfull Width = 115.7 ft.; Bankfull Depth = 2.37 ft. 101 -- a) 100 -- 'm 98 - - --- i �LF a 97 - — -- - -- - - w96 L-----------,--:��___— a 95 - - T � 94 a� w 93 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 110.2 ft.; Active Width = 110.2 ft.; Active Depth = 0.78 ft. 101 - - - -- - - - - d 100 - -- - - - - - - - --- m o' 99 - -- 98 - - - R io F 97 — - - --- w 96 PC PC 0 95 -- - - - T > 94 m w 93 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0028 and Avg Bed Gradient =-0.0011 97 - -- - - - - - - - - 0 m T 96 .E A 95 _ — _ _� 0 m > Ir w 93 130 110 90 70 50 30 10 -10 -30 -50 -70 -90 -110 -130 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) ■ BedEl L * Bed El M A BedEl R +- WaterSurface Seg 16S i te27.123 02/06/02 Segment 16, Site No.27 Cross Section No. 141, at River Mile 9.252 Pebble Count Statistics 260 240 220 200 180 Max E 160 60 d84 m d16 FN 140 Min U 120 G 100 0• MaxMob 80 60 40 41 20 0 A, 78 to 96 B, 96 to 146 C, 40 to 78 D, 0 to 0 Pebble Count 120 100 E E 80 N in 60 CO o_ 40 20 0 Pebble Count Statistics (zoom) Max d84 d16 Min • d50 • MaxMob 160 250 172 113 400 57 67 41 Aft A, 78 to 96 B, 96 to 146 C, 40 to 78 D, 0 to 0 Pebble Count Seg 16Site27.123 02/06/02 Percent Finer Than 0 0 0 0 0 0 0 0 0 0 0 de o 0 0 0 0 0 0 0 0 0 0 O 0 Percent Finer Than 0 0 0 0 0 0 0 0 CO 0 g 0 0 W m N (n F• 0 O 3 C 3 m O O N O O .�. 1, rA lD n N O� �p � 3 Z m 0 A M 1 .lk Cedar River Gravel Study Data Summary for Site No.28, Cross Section No. 131, Located in Segment 16 at River Mile 8.193 Segment Summary Segment 16 is 2.931 miles long, extending from RM 9.625 to RM 6.694. It is generally described as: Jones Road, mostly confined. Average gradient is estimated to be 0.44. Known local sediment sources are: Mid-80s Lake McDonald gully; 100 ft high RB slope at RM 9.6—unknown if a source. Data collected during this study include: Sites 27-29. Other studies active in this segment include: USFWS. Subsegment Summary Description: Flood study cross-section 131 (notes) Widths and Denths Surveyed Width ft 88.7 BF Width (ft) 75.0 BF Depth (ft) 3.73 Width/Depth Ratio (f fft) 20.1 Bed Width (ft) 70.2 Active Width (ft) 70.2 Active Depth (ft) 1.43 Confinement and Banks 10 yr Width (ft) 90.0 10 /BF Ratio 1.20 BF Elevation (ft, datum) 155.7 10 Elevation (ft, datum) 159.11 LB RB Est. % Levee 100 100 Est. % Revetment 100 0 Bank Ht., Typical (ft) 10 6 Bank Ht., Max (ft) 10 7 Material Source Riprap levee fill Dom/Subdom Size Riprap Cob/Gr Bank Size Relative to Bed <25% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Glide Secondary Habitat Types Riffle Gross Spawn Area (sq. ft.) 10500 Percent Usable 60 ASA (sq. ft.) 6300 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment 12 adult 6, 12" trout sockeye Fish Observed, adj. Segment Gradients Survey Length (ft) 150.0 Water Surface Slope (ft/ft' 0.0011 Avg Bed Slope (ft/ft) -0.0066 L25 Bed Slope (ft/ft) -0.0113 M50 Bed Slope (ft/ft) -0.0103 R75 Bed Slope (ft/ft) 0.0017 Geomornholoov Bed Morphology Plane bed Channel Pattern Single Subsegment Adj. Segment Gravel Bar Type None None Bar Material Typ. Bar Width (ft) Max. Bar Width (ft) Max. Bar Width (cw) Bar Vegetation Fine Sediment In Riffles Local, sheltered locations In Pools Local, obstruct, slack Cobble Embeddedness 15-35% Notes, Comments O = 216 at Renton Datum: NAVD88 Bankfull Confidence: Low Bankfull Indicators: Riprap levee on LB, Steep eroding bank RB. ASA Deductions: deep trough with largr substrate on left margine. Pehhie Counts ID A B C D Method Count Visual None None Cross Section Location 69 to 114 44 to 69 0 to 0 0 to 0 Sizes (mm) Maximum mobile 260 280 nd nd Maximum 321 280 nd nd d84 113 240 nd nd d50 41 100 nd nd d 16 3.5 14.5 nd nd Minimum 0.10 0.50 nd nd Seg16Site28.123 02/06/02 Segment 16, Site No.28 Cross Section No. 131, at River Mile 8.193 Channel Cross Section Bankfull Width = 75.0 ft.; Bankfull Depth = 3.73 ft. 162 COCO > 160 E 158 m 0 156 �154 E---------------------R -10 0 152 > a� 150 w 148 30 40 50 60 70 80 90 100 110 120 130 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 70.2 ft.; Active Width = 70.2 ft.; Active Depth = 1.43 ft. 162 CO CO 160 > ¢ z E 158 156 m O_ P 154 — — — — — — — — — — — — — — — — — — — — — (' 0 152 > m 150 w 148 30 40 50 60 70 80 90 100 110 120 130 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0011 and Avg Bed Gradient =-0.0066 152 CO CO > 151 z 150 — — — — - — — — — — — — — — — 19 — 149 -- -- 148 — — --- — — — — c 0— — — — — — m 147 a� w 146 90 70 50 30 10 -10 -30 -50 -70 -90 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) ■ BedEl L*- BedEl M k BedEl R t WaterSurface Seg16Site28.123 02/06/02 Segment 16, Site No.28 Cross Section No. 131, at River Mile 8.193 Pebble Count Statistics 340 Max d84 d16 Min • d50 • MaxMob 320 300 280 80 260 240 240 E220 v 200 N 180 CO 160 ,v 140 cu 120 100 0100 80 60 40 20 0 A,69to114 B,44to69 C,0to0 D,0to0 Pebble Count Pebble Count Statistics (zoom) 240 260 240 220 200 180 E 160 N 140 U) a� 120 —113 U E 100 co 190 a 80 60 441 40 20 lk- 0 A, B,44to69 C,0too D,0to0 Pebble Count Max d84 d16 Min • d50 • MaxMob Seg 16Site28.123 02/06/02 Segment 16, Site No.28 Cross Section No. 131. at River Mile 8.193 Pebble Count A 100% -- 32 90% 80% r C 70% m L 60% 4 C i 50% c 2 40% a 30% 20% 10% 0% 1 10 100 1000 Partite Size (mm) Pebble Count 8 100% 90% 80% C 70% m L 60% N C_ 50% C m 40% QJ d 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% C 70% m L 60% N C u_ 50% C 2 40% N o_ 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Seg t 6Site28.123 02!06102 Cedar River Gravel Study Data Summary for Site No.29, Cross Section No. 123, Located in Segment 16 at River Mile 7.395 Segment Summary Segment 16 is 2.931 miles long, extending from RM 9.625 to RM 6.694. It is generally described as: Jones Road, mostly confined. Average gradient is estimated to be 0.44. Known local sediment sources are: Mid-80s Lake McDonald gul y; 100 ft high RB slope at RM 9.6--unknown if a source. Data collected during this study include: Sites 27-29. Other studies active in this segment include: USFWS. Subsegment Summary Description: Flood study cross-section 123 (notes) Widths and Deaths Surveyed Width (ft) 102.2 BF Width (ft) 95.9 BF Depth (ft) 3.56 Width/Depth Ratio (f tft) 26.9 Bed Width (ft) 86.5 Active Width (ft) 86.5 Active Depth (ft) 1.04 Confinement and Ranks 10 yr Width (ft) 180.0 10 /BF Ratio 1.88 BF Elevation (ft, datum) 96.8 10 yr Elevation (ft, datum) 141.39 LB RB Est. % Levee 0 0 Est. % Revetment 100 0 Bank Ht., Typical (ft) 7 2 Bank Ht., Max (ft) 8 4 Material Source riprap alluvial Dom/Subdom Size riprap Gr/Sa/Cob Bank Size Relative to Bed 25-75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types None Gross Spawn Area (sq. ft.) 7920 Percent Usable 70 ASA (sq. ft.) 5544 R2 Habitat Type Other Fish Field Fish Observed, in None Subsegment Fish Observed, adj. Segment Gradients Survey Length (ft) 192.0 Water Surface Slope (ft/ft; 0.0017 Avg Bed Slope (ft/ft) 0.0007 L25 Bed Slope (ft/ft) -0.0029 M50 Bed Slope (fUft) 0.0011 R75 Bed Slope (ft/ft) 0.0039 Geomoroholoov Bed Morphology Plane bed Channel Pattern Single Subsegment Adj. Segment Gravel Bar Type None None Bar Material Typ. Bar Width (ft) Max. Bar Width (ft) Max. Bar Width (cw) Bar Vegetation Fine Sediment In Riffles Local, sheltered locations In Pools N/A Cobble Embeddedness 15-35% Notes, Comments Q = 216 at Renton Datum: Relative Bankfull Confidence: nd BankfullIndicators: nd ASA Deductions: large substrate along left margin and in thalwag Pebble Cnunts ID A B C D Method Count Visual None None Cross Section Location 130 to 69 69 to 43 0 to 0 0 to 0 Sizes (mm) Maximum mobile 280 240 nd nd Maximum 321 240 nd nd d84 81 161 nd nd d50 41 57 nd nd d16 20.5 40.5 nd nd Minimum 0.10 20.00 nd nd Seg 16Site29.123 02/06/02 Segment 16, Site No.29 Cross Section No. 123, at River Mile 7.395 Channel Cross Section Bankfull Width = 95.9 ft.; Bankfull Depth = 3.56 ft. 99 d 98 L F 97 96 R 95 94 c 93 T >>i 92 w 91 30 40 50 60 70 80 90 100 110 120 130 140 150 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 86.5 ft.; Active Width = 86.5 ft.; Active Depth = 1.04 ft. 99 m 98 L F 97 96 m 95 — — — — — — — — — — — — — — — — — — — — — — P 94 93 m T PC 92 w 91 30 40 50 60 70 80 90 100 110 120 130 140 150 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0017 and Avg Bed Gradient = 0.0007 95 d m F E 94 • — — — — — — — 93 — — — I c w 92 110 90 70 50 30 10 -10 -30 -50 -70 -90 -110 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) • BedEl L � BedEl M -A BedEl R +- WaterSurface Seg 16Site29.123 02/06/02 Segment 16, Site No.29 Cross Section No. 123, at River Mile 7.395 Pebble Count Statistics 340 320 300 280 260 240 E 220 200 N 180 aD 160 161140 m 120 100 80 60 40 20 0 A, 130 to 69 B, 69 to 43 C, 0 to 0 D, 0 to 0 Pebble Count Max d84 d16 Min • d50 • MaxMob 200 180 160 140 E 120 N Fn 100 m 80 60 40 20 0 Pebble Count Statistics (zoom) Max d84 d16 Min d50 • MaxMob 80 40 161 81 .41 A, 130 to 69 B, 69 to 43 C, 0 to 0 D, 0 to 0 Pebble Count Seg 16Site29.123 02/06/02 Segment 16, Site No.29 Cross Section No. 123, at River Mile 7.395 Pebble Count A 100% 32 90% 80% c 70% m 60% 00 4 Cc ii 50% c 40% `m a 30% 2 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% F 90% 80% - c 70% m L ~ 60% ii 50% k c F ai c40% 2 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% — c 70% m L 60% U- 50% c u 40% iv a 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Segl6Site29.123 02-06'02 RNI 7.395, Segment 16, Site 29 Cedar River Gravel Study Data Summary for Site No.30, Cross Section No. 111, Located in Segment 17 at River Mile 6.216 Segment Summary Segment 17 is 1.484 miles long, extending from RM 6.694 to RM 5.210. It is generally described as: Elliott Br, flatter, confined. Average gradient is estimated to be 0.37. Known local sediment sources are: None observed. Data collected during this study include: Sites 30-31. Other studies active in this segment include: USFWS. Subsegment Summary Description: Flood study cross-section 111 (notes). Widths and Depths Surveyed Width (ft) 175.0 BF Width (ft) 105.8 BF Depth (ft) 2.40 Width/Depth Ratio (ft1 t) 44.1 Bed Width (ft) 77.1 _ Active Width (ft) 77.1 Active Depth (ft) 1.03 Confinement and Banks 10 yr Width (ft) 335.0 10 yr/BF Ratio 3.17 BF Elevation (ft, datum) 93.0 10 yr Elevation (ft, datum) 114.35 LB RB Est. % Levee 0 0 Est. % Revetment 0 0 Bank Ht., Typical (ft) 3 2 Bank Ht., Max (ft) 6 2 Material Source alluvial alluvial Dom/Subdom Size Cob/Gr Sm/Lg Cob Bank Size Relative to Bed 25-75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types None Gross Spawn Area (sq. ft.) 20482 Percent Usable 25 ASA (sq. ft.) 5120.5 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment 3 adult sockeye; 1 adult chinook; 1 unidentified fry -2" Fish Observed, adj. Segment Gradients Survey Length (ft) 266.0 Water Surface Slope (ft/ft: 0.0075 Avg Bed Slope (ft/ft) 0.0094 L25 Bed Slope (fttft) 0.0082 M50 Bed Slope (ft/ft) 0.0077 R75 Bed Slope (ft/ft) 0.0123 Geomorphology Bed Morphology Plane bed Channel Pattem Single Subsegment I Adj. Segment Gravel Bar Type Point None Bar Material Gr/Cob Typ. Bar Width (ft) 40 Max. Bar Width (ft) 47 Max. Bar Width (cw) 0.4 Bar Vegetation Encroaching vegetation Fine Sediment In Riffles Local, sheltered locations In Pools N/A Cobble Embeddedness <15% Notes, Comments \ Did another pebble count -500 ft u/s of this subsegment (-200' d/s of XS 112) on a very uniform rectangular cross section where ASA was est. aQ 95% (compare to 25% at this XS); Pt bar now maintains RBF separate Q = 192 at Renton from terrace by small side channel Datum: NAVD88 Bankfull Confidence: High Bankfull Indicators: Slope break on old? RB bar w/ establishing veg; Veg. on LB is questionable ASA Deductions: larger substrate throughout, and high velocity in d/s left corner of transect Road functions as levee further d/s on right bank Pebble Counts ID A B C D Method Count Visual Count None Cross Section Location 84 to 106 52 to 84 (500 ft u/s in segment) 0 to 0 Sizes (mm) Maximum mobile 360 nd nd nd Maximum 321 321 161 nd d84 161 161 81 nd d50 81 81 41 nd d16 28.5 28.5 20.5 nd Minimum 0.10 0.10 1.50 nd Seg17Site30.123 02/06/02 Segment 17, Site No.30 Cross Section No. 111, at River Mile 6.216 Channel Cross Section Bankfull Width = 105.8 ft.; Bankfull Depth = 2.40 ft. E CO 99 0 98 97 ., 96 E 95 0 93 LV F RBF C92 — — — — — — — to I 90 f0 >89 ai w 88 0 20 40 60 80 100 120 140 160 180 10 30 50 70 90 110 130 150 170 190 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 77.1 ft.; Active Width = 77.1 ft.; Active Depth = 1.03 ft. 00 99 CO 0 98 97 .. 96 E 95 94 LID F RBF 93 92 c91 ------------ 0 90 f0 T >89 ai w 88 0 20 40 60 80 100 120 140 160 180 10 30 50 70 90 110 130 150 170 190 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0075 and Avg Bed Gradient = 0.0094 m 93 00 0 r 92 z E 2 91M ' -- IF m 90 0 89 cc d w 88 150 130 110 90 70 50 30 10 -10 -30 -50 -70 -90 -110 -130 -150 Distance Relative to Cross Section (0) from L1/S (+) to D/S (-) (feet) It BedEl L � Bed El M -i BedEl R i- WaterSurface Seg 17Site30. l 23 02/06/02 Segment 17, Site No.30 Cross Section No. 111, at River Mile 6.216 Pebble Count Statistics 380 360 6 340 320 300 280 260 Max E 240 d84 220 d 16 iz 180 Min 160 1 fr 140 • d50 n 120 • MaxMob 100 80 60 40 20 0 A, 84 to 106 B, 52 to 84 C, 0 to 0 D, 0 to 0 Pebble Count "A" is pebble count and "B" is visual estimate within subsegment; "C" is pebble count on uniform XS 500 ft u/s Pebble Count Statistics (zoom) 200 180 160 140 Max E 120 d84 N d16 65 100 Min a) 80 • d50 cU • MaxMob 60 40 20 0 A, 84 to 106 B, 52 to 84 C, 0 to 0 D, 0 to 0 Pebble Count "A" is pebble count and "B" is visual estimate within subsegment; "C" is pebble count on uniform XS 500 ft u/s Seg17Site30.123 02/06/02 Segment 17, Site No.30 Cross Section No. 111, at River Mile 6.216 Pebble Count B 100% go% 80% C 70% m L 60% a� C ii 50% t c 40% 2 30% 20 % 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C u/s of subsegment at uniform XS with 95% ASA 100% 11 90% 80% -44 C 70% L 60% c ii 50% C 40% U Z N o_ 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Segl 7Site30.123 02/06/02 W INCOME NONE MEN 0 ONE MEN on no, Cedar River Gravel Study Data Summary for Site No.31, Cross Section No. 105m, Located in Segment 17 at River Mile 5.613 Segment Summary Segment 17 is 1.484 miles long, extending from RM 6.694 to RM 5.210. It is generally described as: Elliott Br, flatter, confined. Average gradient is estimated to be 0.37. Known local sediment sources are: None observed. Data collected during this study include: Sites 30-31. Other studies active in this segment include: USFWS. Subsegment Summary Description: Located about 250 ft upstream of flood study cross-section 105 & about 550 ft d/s of xs 106; xs 105, proposed for surveying, was slightly steeper and faster than typical for this segment Widths and Depths Surveyed Width (ft) 146.0 BF Width (ft) 98.9 BF Depth (ft) 2.05 Width/Depth Ratio (ft/ft) 48.3 Bed Width (ft) 93.7 Active Width (ft) 93.7 Active Depth (ft) 0.58 Confinement and Banks 10 yr Width (ft) 225.0 10 yr/BF Ratio 2.28 BF Elevation (ft, datum) 98.2 10 yr Elevation (ft, datum) 103.22 LB RB Est. % Levee 0 0 Est % Revetment 0 100 Bank Ht., Typical (ft) 4 6 Bank Ht., Max (ft) 5 6 Material Source alluvial levee fill Dom/Subdom Size Sa/Gr Sm Bldr Bank Size Relative to Bed 25-75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types None Gross Spawn Area (sq. ft.) 18800 Percent Usable 85 ASA (sq. ft.) 15980 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment None Fish Observed, adj. Segment —24 adult sockeye Gradients Survey Length (ft) 198.0 Water Surface Slope (ft''ft 0.0021 Avg Bed Slope (ft/ft) 0.0013 L25 Bed Slope (ft/ft) 0.0029 M50 Bed Slope (ft/ft) 0.0023 R75 Bed Slope (ft/ft) -0.0012 Geomorphology Bed Morphology Plane bed _ Channel Pattern Single Subsegment I Adj. Segment Gravel Bar Type None None Bar Material Typ. Bar Width (ft) Max. Bar Width (ft) Max. Bar Width (cw) Bar Vegetation Fine Sediment In Riffles Local, sheltered locations In Pools N/A Cobble Embeddedness <15% Notes, Comments _ Measured RMile from photo between XS's at RMs 5.566 and 5.711 10 yr elevation and width obtained by averaging data and measuring maps between these two XS's Q = 192 at Renton Datum: NAVD88 Bankfull Indicators: LB has slope break, but it's hidden in dense brush; landscaped RB Pebble Counts ID A B C D Method Count None None None Cross Section Location 151 to 57 0 to 0 0 to 0 0 to 0 Sizes (mm) Maximum mobile 190 nd nd nd Maximum 161 nd nd nd d84 113 nd nd nd d50 41 nd nd nd d16 20.5 nd nd nd Minimum 5.50 nd nd nd Seg17Site31.123 02/06/02 Segment 17, Site No.31 Cross Section No. 105m, at River Mile 5.613 Channel Cross Section Bankfull Width = 98.9 ft.; Bankfull Depth = 2.05 ft. 106 CO 105 0 > 104 z 103 102 E 101 100 99RPF 98 c 97-113 o— — — — — — — — — — — — — — — — 96 m 95 w 94 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 93.7 ft.; Active Width = 93.7 ft.; Active Depth = 0.58 ft. 105.6 CO p 104.4 z 103.2 E 102 0 100.8 99.6 w 98.4 c 2 97.2 > 96 m w 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 Distance from LB to RB (feet) Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0021 and Avg Bed Gradient = 0.0013 98 COCO z 97 E m 96 0 • — — — — _ — — — — — — — _ _ _ _ _ — — — — — — — - — — — —95 m 0 cc a� w 94 110 90 70 50 30 10 -10 -30 -50 -70 -90 -110 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) BedEl L + BedEl M t BedEl R +- WaterSurface Segl7Site31.123 02/06/02 Segment 17, Site No.31 Cross Section No. 105m, at River Mile 5.613 Pebble Count Statistics 200 180 160 140 E Max 120 d84 N d16 100 Min a1 80 • d50 n 60 • MaxMob 40 20 0 A,151to57 B4Oto0 C,0to0 D,0to0 Pebble Count Pebble Count Statistics (zoom) 120 190 113 100 E 80 Max E d84 N d16 in 60 Min am • d50 a 40 " • MaxMob 20 0 A,151to57 B4Oto0 C,0to0 D,0to0 Pebble Count Seg 17Site31.123 02/06/02 Segment 17, Site No.31 Cross Section No. 105m, at River Mile 5.613 Pebble Count A 100% 16 90% 80% c 70% m L 60% Q1 4 c LT 50% r c 40% `m 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% K 90% 80% c 70% m L 60% `m c ' ii 50% c u 40% `m o- 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Segl7Site31.123 02/06/02 N.,a - E: w eD cra rD a w Cedar River Gravel Study Data Summary for Site No.32, Cross Section No. BM, Located in Segment 19 at River Mile 4.702 Segment Summary Segment 19 is 0.265 miles long, extending from RM 4.841 to RM 4.576. It is generally described as: Unconfined, side channels. Average gradient is estimated to be tbd. Known local sediment sources are: Minor cliff erosion on 100+ ft high RB slope at RM 4.6. Data collected during this study include: Site 32. Other studies active in this segment include: USFW S. Subsegment Summary Description: Just upstream of large medial gravel bar. Widths and Depths Surveyed Width (ft) 152.0 BF Width (ft) 143.7 BF Depth (ft) 2.32 Width/Depth Ratio (f fft) 61.9 Bed Width (ft) 132.6 Active Width (ft) 116.3 Active Depth (ft) 0.52 Confinement and Banks 10 yr Width (ft) 0.0 10 yrBF Ratio 0.00 BF Elevation (ft, datum) 99.5 10 yr Elevation (ft, datum) nd LB RB Est. % Levee 0 0 Est. % Revetment 0 0 Bank Ht., Typical (ft) <2' 2' Bank Ht., Max (ft) 3 3' Material Source alluvial alluvial Dom/Subdom Size Sa/Gr Sa/Gr Bank Size Relative to Bed >75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types None Gross Spawn Area (sq. ft.) 33640 Percent Usable 60 ASA sq. ft.) 20184 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment many 1.5" sculpins Fish Observed, adj. Segment Gradients Survey Length (ft) 290.0 Water Surface Slope (ft/ft: 0.0065 Avg Bed Slope (ft/ft) 0.0045 L25 Bed Slope (ft/ft) 0.0028 M50 Bed Slope (ft/ft) 0.0002 R75 Bed Slope (ft/ft) 0.0043 Geomorphology Bed Morphology Plane bed Channel Pattern Single Subsegment I Adj. Segment Gravel Bar Type Medial None Bar Material Typ. Bar Width (ft) Max. Bar Width (ft) Max. Bar Width (cw) Bar Vegetation Established vegetation Fine Sediment In Riffles Local, sheltered locations In Pools N/A Cobble Embeddedness 15-35% Notes, Comments u/s tip of gravel bar in channel center is 100 ft d/s of cross section Habitat type riffle has distinct slower and very fast (d/s) areas —see profit 0 =190 at Renton Datum: Relative Bankfull Confidence: Mod Bankfull Indicators: slope breaks, veg; LB fine sediment deposition continues above "LBF" ASA Deductions: packed gravel in margins, extra fines, medial gravel bar, steep, fast riffle near lower end of cross-section Pebble Counts ID A B C D Method Count Visual None None Cross Section Location 54 to 158 158 to 171 0 to 0 0 to 0 Sizes (mm) Maximum mobile 220 nd nd nd Maximum 225 2 nd nd d84 81 2 nd nd d50 41 1 nd nd d16 5.5 0.1 nd nd Minimum 0.10 0.10 nd nd Seg19Site32.123 03/14/02 Segment 19, Site No.32 Cross Section No. BM, at River Mile 4.702 Channel Cross Section Bankfull Width = 143.7 ft.; Bankfull Depth = 2.32 ft. r 102 a� 1° z 101 E RiF 100 m LBF 99 d c 98 L — — — — — — — — — — — — — — — o— cc > 97 T a� Li I JV 96 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 132.6 ft.; Active Width = 116.3 ft.; Active Depth = 0.52 ft. m 102 m 100.8 o: E R F 99.6 LBF 0 6 98.4 0 PC-------------P —P m 97.2 — --- > T m w 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0065 and Avg Bed Gradient = 0.0045 m 99 m 98 Q: E 97 0 w 96 c 95 a� w 94 160 140 120 100 80 60 40 20 0 -20 -40 -60 -80 -100 -120 -140 -160 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) BedEl L + BedEl M f BedEI R *' WaterSurface Segl9Site32.123 03/14/02 Segment 19, Site No.32 Cross Section No. BM, at River Mile 4.702 Pebble Count Statistics 240 220 200 180 160 Max E d84 N 140 d16 in 120 Min a> 100 • d50 a 80 • MaxMob 60 40 41 20 0 A, 54 to 158 B, 158 to 171 C, 0 to 0 D, 0 to 0 Pebble Count Pebble Count Statistics (zoom) 100 220 81 80 E Max 60 d84 N �n d16 Min a) 40 `a o_ • d50 • MaxMob 20 0 r A, 54 to 158 B, 158 to 171 C, 0 to 0 D, 0 to 0 Pebble Count Seg 19Site32.123 03/14/02 Segment 19, Site No.32 Cross Section No. BM, at River Mile 4.702 Pebble Count A 100% 225 90% - 8 80% C 70% m L 60% N 4 C_ u. 50% C 40%2 lox ~ IL 30% r F 20% 10% k r ' 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% C 70% m L 60% c ii 50% c u 40% 2 °' 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) S eg 19S i te32.123 03/14/02 Cedar River Gravel Study Data Summary for Site No.33, Cross Section No. CQ, Located in Segment 20 at River Mile 4.380 Segment Summary Segment 20 is 1.326 miles long, extending from RM 4.576 to RM 3.250. It is generally described as: Maplewood, mostly confined. Average gradient is estimated to be tbd. Known local sediment sources are: Molasses Crk, stable, at RM 4.1; Maplewood Crk, unstable, at RM 3.3); minor cliff erosion, huge 1987 slide at RM?. Data collected during this study include: Sites 33-34. Other studies active in this segment include: USFWS. Subsegment Summary Description: Next to golf course Widths and Depths Surveyed Width (ft) 193.2 BF Width (ft) 180.8 BF Depth (ft) 1.59 Width/Depth Ratio (ft/ft) 113.8 Bed Width (ft) 145.3 Active Width (ft) 145.3 Active Depth ft 0.80 Confinement and Banks 10 yr Width (ft) 229.0 10 /BF Ratio 1.27 BF Elevation (ft, datum) 94.8 10 yr Elevation (ft, datum) nd LB RB Est. % Levee 0 0 Est. % Revetment 0 100 Bank Ht., Typical (ft) nd 5 Bank Ht., Max (ft) nd 6 Material Source alluvial fill/ri ra Dom/Subdom Size Gr/Cob fill/ri ra Bank Size Relative to Bed >75% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types Glide Gross Spawn Area (sq. ft.) 52200 Percent Usable 40 ASA (sq. ft.) 20880 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment many 1-2" sculpins Fish Observed, adj. Segment ID Method Cross Section L Sizes Maximum mo Maximum d84 d50 d16 Minimum Gradients SurveyLength ft 360.0 Water Surface Slope (ft/ft 0.0084 Avg Bed Slope ft/ft) 0.0053 L25 Bed Slopeft/ft) 0.0044 M50 Bed Slope (ft/ft) 0.0066 R75 Bed Slope(ft/ft 0.0049 Geomorphology Bed Morphology Plane bed Channel Pattern Single Subsegment Adj. Segment Gravel Bar Type Medial None Bar Material nd T . Bar Width ft rid Max. Bar Width (ft) nd Max. Bar Width cw nd Bar Vegetation Encroaching vegetation Fine Sediment In Riffles Strands d/s obstructions In Pools Widespread Cobble Embeddedness <15% Notes, Comments Fine sed accumulations only near channel margins; however, as in seg. 20, it is silty below the armor layer. Q = 190 at Renton Datum: Relative Bankfull Confidence: LOW Bankfull Indicators: revetment conceals slope break on RB; wide, LBF is in error (too low) due to dense thicket on LB ASA Deductions: steep riffle, large substrate, very sandy margins Pebble Counts A mm) B C D Count Visual Visual None ocation 158 to 60 182 to 158 196 to 182 0 to 0 bile 200 115 nd nd 225 115 1537 nd 113 100 29 nd 57 70 2 nd 7.5 30.0 1.0 nd 0.10 0.10 0.10 nd Seg20Site33.123 02/06/02 Segment 20, Site No.33 Cross Section No. CQ, at River Mile 4.380 Channel Cross Section Bankfull Width = 180.8 ft.; Bankfull Depth = 1.59 ft. 100 m 99 98 E 97 0 96 R F 95 a� ='94 — ---------------- c 93 T 92 w 91 10 30 50 70 90 110 130 150 170 190 210 230 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 145.3 ft.; Active Width = 145.3 ft.; Active Depth = 0.80 ft. 100 a� 99 98 E 97 0 96 R F m 95 -- 94Pr —— — — — — — — — — — — -- c 93 T a' 92 w 91 10 30 50 70 90 110 130 150 170 190 210 230 Distance from LB to RB (feet) — Elev — WaterSurface Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0084 and Avg Bed Gradient = 0.0053 a� m 95 94 m 93 ----- — a� 92 ------ c 91 o 90 y w 89 200 160 120 80 40 0 -40 -80 -120 -160 -200 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) ■ BedEl L + BedEl M - BedEl R -} WaterSurface Seg20Site33.123 02/06/02 Segment 20, Site No.33 Cross Section No. CQ, at River Mile 4.380 Pebble Count Statistics 1600 1400 1200 E Max 1000 d84 N d16 ai 800 Min U r • d50 a 600 • MaxMob 400 200 0 0 7 s A, 158 to 60 B, 182 to 158 C, 196 to 182 D, 0 to 0 Pebble Count 200 180 160 140 E N 120 in 100 a� E 80 CO a- 60 40 20 0 Pebble Count Statistics (zoom) Max d84 d16 Min • d50 • MaxMob 200 15 100 2 A, 158 to 60 B, 182 to 158 C, 196 to 182 D, 0 to 0 Pebble Count Seg20Site33.123 02/06/02 Segment 20, Site No.33 Cross Section No. CQ, at River Mile 4.380 Pebble Count A 100% 5 90% t 80% C 70% m L 1-- 60% N C ii 50% C 40% N a 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% 90% 80% C 70% m L 60% c ii 50% C 40% 61 d 30% 20% 10%777, 0% : - 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% C 70% m L 60% N C u 50% C 40% N n' 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) S eg20 S i to 33.123 02/06, 02 i -\ D - I- I- --- ■■ ■■■■■■■■■■■■■ ■■■■ ■■■ ■■ ■■■■■■■■■ ■ ■■■■■■���■���]I�r��.rl��!'�!!!�`llril� i --••rrrr�r ■ . �R � i �I� ^.,� .,Aim ...ter= ■■■■■■■■■■■■■■■ ■ ■� ... a 344S -7l I b� Cedar River Gravel Study Data Summary for Site No.34, Cross Section No. AX, Located in Segment 20 at River Mile 3.548 Segment Summary Segment 20 is 1.326 miles long, extending from RM 4.576 to RM 3.250. It is generally described as: Maplewood, mostly confined. Average gradient is estimated to be tbd. Known local sediment sources are: Molasses Crk, stable, at RM 4.1; Maplewood Crk, unstable, at RM 3.3); minor cliff erosion, huge 1987 slide at RM?. Data collected during this study include: Sites 33-34. Other studies active in this segment include: USFWS. Subsegment Summary Description: Between gray and white house on RB Widths and Depths Surveyed Width (ft) 131.0 BF Width (ft) 115.0 BF Depth (ft) 2.40 Width/Depth Ratio (ft/ft) 47.9 Bed Width (ft) 112.3 Active Width (ft) 112.3 Active Depth (ft) 0.69 Confinement and Banks 10 yr Width (ft) 129.0 10 yr/BF Ratio 1.12 BF Elevation (ft, datum) 100.7 10 yr Elevation ft, datum) nd LB RB Est % Levee 0 0 Est. % Revetment 0 100 Bank Ht, Typical (ft) 5 5 Bank Ht., Max (ft) 6 8 Material Source alluvial riprap Dom/Subdom Size Cob/Gr riprap Bank Size Relative to Bed 25-75'/0 < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Glide Secondary Habitat Types Riffle Gross Spawn Area (sq. ft.) 25536 Percent Usable 75 ASA (sq. ft.) 19152 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment 4 sculpins Fish Observed, adj. Segment Gradients Survey Length (ft) 238.0 Water Surface Slope (ft/ft' 0.0017 Avg Bed Slope (ft/ft) -0.0021 L25 Bed Slope (ft/ft) -0.0016 M50 Bed Slope (ft/ft) -0.0013 R75 Bed Slope (ft/ft) -0.0034 Geomorphology Bed Morphology Plane bed Channel Pattern Single Subsegment I Adj. Segment Gravel Bar Type None None Bar Material Typ. Bar Width (ft) Max. Bar Width (ft) Max. Bar Width (cw) Bar Vegetation Fine Sediment In Riffles Thin draping Ig clasts In Pools WA Cobble Embeddedness 15-35% Notes, Comments Riffle subunit is near downstream end of transect Q =190 at Renton Datum: Relative Bankfull Confidence: nd Bankfull Indicators: nd ASA Deductions: deduct for fines (sand) Pebble Counts ID A B C D Method Count Visual None None Cross Section Location 33 to 129 129 to 145 0 to 0 0 to 0 Sizes (mm) Maximum mobile 150 nd nd nd Maximum 161 60 nd nd d84 57 30 nd nd d50 29 20 nd nd d 16 3.5 1.5 nd nd Minimum 0.10 0.10 nd nd Seg20Site34.123 02/06/02 Segment 20, Site No.34 Cross Section No. AX, at River Mile 3.548 Channel Cross Section Bankfull Width = 115.0 ft.; Bankfull Depth = 2.40 ft. 108 RPIN 107 —�, 106 o: 105 LPIN E 104 p 103 w 102 RQf 101 c 0 100 99 � 98 w 97 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 112.3 ft.; Active Width = 112.3 ft.; Active Depth = 0.69 ft. 108 107 106 m 105 E 104 p 103 102 R 101 c 0 100 99 a>i 98 w 97 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 Distance from LB to RB (feet) — Elev — WaterSurface E —' 98.5 m 0 m 98 c m 97.5 m w 97 Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0017 and Avg Bed Gradient =-0.0021 ---—===---------- 140 120 100 80 60 40 20 0 -20 -40 -60 -80 -100 -120 -140 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) f BedEl L♦ BedEl M f BedEl R -+- WaterSurface Seg20Site34.123 02/06/02 Segment 20, Site No.34 Cross Section No. AX, at River Mile 3.548 Pebble Count Statistics 160 140 120 E Max 100 d84 N d16 80 Min U r • d50 a 60 57 • MaxMob 40 20 420 0 A, 33 to 129 B, 129 to 145 C, 0 to 0 D, 0 to 0 Pebble Count Pebble Count Statistics (zoom) 80 150 70 60 57 E 50 Max d84 N d16 ?n 40 Min CD U_ 30 • d50 IL • MaxMob 20 — 20 10 C 0 A, 33 to 129 B, 129 to 145 C, 0 to 0 D, 0 to 0 Pebble Count Seg20Site34.123 02/06/02 Segment 20, Site No.34 Cross Section No. AX, at River Mile 3.548 Pebble Count A 100% 16 90%- 80% - C 70% - 60%29 - v t ii 50% F 2 40% 30% t 20% 10% r 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100 90% 80 70 C c° L r- 60% N C ii 50% c u 40% `m o_ 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80% c 70% m 60% � I c - 50% u 40% `m a 30% -- -- 20% 10% 0% 1 10 100 1000 Particle Size (mm) Seg20Site34.123 02/06,02 RAI 3.548, Segment 20, Site 34 a� - s t Zz v MEMBEEMIUMIMEN EMNAMMIME■■■■ ■■■C!Jii■f ■■■■�■LC`■aF� ■■EW■■■■■ ®'ice. _ �■■i■li:�!■�u��1■!!C■■1■■ �■■�c���,i!■■��-■�■■���■■■ram■■ ■■iir!■.01,01 I!■■■1 ■■■■B� snow i■ii■ ii�■�.:lJ■�.�■■ill/ . �iil�t�71�■'�`�■■ I■■ilV_rl_ ■\■ .. I�R■- ` . �AN.�" INIM■Z■■ �iii■i�i���iiiri■�a���aw �i !I�!■■■i���!■■■.!■i■■:� Y■■■ice■■ � �i�i■■■■RMI, O■■I!�■■■. ii■■■■■■■■ Yi�i■■■ltii■■■1!W■C��■■Y■■■■■■ :■ ■■G rIM No■-MER-I'!■■!■■■■■ mar■!�■■rr■�■���a■r■■■■ l�■!■■iAY■W ..i►.�!■f■■■■■■ Cedar River Gravel Study Data Summary for Site No.35, Cross Section No. AP, Located in Segment 21 at River Mile 2.286 Segment Summary Segment 21 is 1.617 miles long, extending from RM 3.250 to RM 1.633. It is generally described as: Confined, even flatter. Average gradient is estimated to be 0.32. Known local sediment sources are: Ginger Cr, Ig trib source of coarse sed, at RM 2.4; eroding slide at RM 1.7 with sand/fine gravel. Data collected during this study include: Site 35. Other studies active in this segment include: JSA. Subsegment Summary Description: Between 2 foot bridges. Widths and Depths Surveyed Width (ft) 97.6 BF Width (ft) 87.5 BF Depth (ft) 3.58 Width/Depth Ratio (ft/ft) 24.4 Bed Width (ft) 78.5 Active Width (ft) 84.3 Active Depth (ft) 1.18 Confinement and Banks 10 yr Width (ft) 110.0 10 /BF Ratio 1.26 BF Elevation (ft, datum) 100.0 10 yr Elevation (ft, datum) nd LB RB Est. % Levee 0 0 Est. % Revetment 100 100 Bank Ht., Typical (ft) 5 12 Bank Ht., Max (ft) 8 15 Material Source riprap/alluvial riprap/alluvial Dom/Subdom Size riprap/Gr/Cobriprap/Cob/G Bank Size Relative to Bed <25% < c.s. Bank Erosion Local, forced, obstructions Fish and Habitat Dominant Habitat Type Riffle Secondary Habitat Types None Gross Spawn Area (sq. ft.) 14784 Percent Usable 75 ASA (sq. ft.) 11088 R2 Habitat Type Other Fish Field Fish Observed, in Subsegment None Fish Observed, adj. Segment Gradients Survey Length (ft) 174.0 Water Surface Slope (ftlk 0.0024 Avg Bed Slope (ft/ft) 0.0028 L25 Bed Slope (ftt t) 0.0043 M50 Bed Slope (ft/ft) 0.0024 R75 Bed Slope (ft/ft) 0.0017 Geomorphology Bed Morphology Plane bed Channel Pattern Single Subsegment I Adj. Segment Gravel Bar Type None None Bar Material Typ. Bar Width (ft) Max. Bar Width (ft) Max. Bar Width (cw) Bar Vegetation Fine Sediment In Riffles Local, sheltered locations In Pools _ N/A Cobble Embeddedness 15-35% \ Notes, Comments Could not find flood study benchmark Q = 190 at Renton Datum: Relative Bankfull Confidence: High Bankfull Indicators: slope breaks and veg. (alder), on both banks despite revetment ASA Deductions: deduct for packing of bed Pebble Counts ID A B C D Method Count None None None Cross Section Location 37 to 116 0 to 0 0 to 0 0 to 0 Sizes (mm) Maximum mobile 180 nd nd nd Maximum 113 nd nd nd d84 81 nd nd nd d50 41 nd nd nd d16 28.5 nd nd nd Minimum 0.10 nd nd nd Seg21 Site35.123 02/05/02 Segment 21, Site No.35 Cross Section No. AP, at River Mile 2.286 Channel Cross Section Bankfull Width = 87.5 ft.; Bankfull Depth = 3.58 ft. 103 > 102 a� 101 100 R qK m 99 — — — — — — — — ------------- 98 c R 97 T 96 L a>i w 95 20 30 40 50 60 70 80 90 100 110 120 130 Distance from LB to RB (feet) — Elev — WaterSurface Cross Section with Pebble Count Boundaries Streambed Width = 78.5 ft.; Active Width = 84.3 ft.; Active Depth = 1.18 ft. 103 a� 102 Z Qf 101 R 100 m 99 — — — — — — — — — — — — — — — — — — — — — — — a�i 98 0 P 97 T > 96 aT tu 95 20 30 40 50 60 70 80 90 100 110 120 130 Distance from LB to RB (feet) — Elev — WaterSurface E m 97.5 0 w 97 C 96.5 w 96 Longitudinal Profile Showing Water Surface and Left, Middle, and Right Bed Elevations Avg Water Surface Slope = 0.0024 and Avg Bed Gradient = 0.0028 100 80 60 40 20 0 -20 -40 -60 Distance Relative to Cross Section (0) from U/S (+) to D/S (-) (feet) f BedEl L -I,- BedEl M A- BedEl R -A� WaterSurface -80 -100 Seg21 Site35.123 02/05/02 Segment 21, Site No.35 Cross Section No. AP, at River Mile 2.286 190 180 170 160 150 140130 E 120 110 ^t- 100 90 800 o_ 60 50 40 30 20 10 0 Pebble Count Statistics Max d84 d16 Min • d50 • MaxMob 04180 — ---- - - -- A,37to116 B4Oto0 C,0to0 D,0to0 Pebble Count Pebble Count Statistics (zoom) 120 - 180 - -- -- 110 - 100 90 80 Max E d84 N 70 d16 in 60 - Min a> 50 • d50 cL 40 • MaxMob 30 20 10 0 r A,37to116 B4Oto0 C,0to0 D,0to0 Pebble Count Seg21 Site35.123 02/05/02 Segment 21, Site No.35 Cross Section No. AP, at River Mile 2.286 Pebble Count A 100% 113 90% 80% c 70% m L 60% N 41 C i 50% c 2 40% m 30% 29 20% 10% ITF7 0% 1 10 100 1000 Particle Size (mm) Pebble Count B 100% 90% 80 % 70% m L � 60% `C C E 50% C u 40% N a 30% 20% 10% 0% 1 10 100 1000 Particle Size (mm) Pebble Count C 100% 90% 80 % c 70% N L r- 60% °I C (� 50 C u 40% m` a 30% 1 20% 10% - I 0% 1 10 100 1000 Particle Size (mm) Seg21 Site35.123 02/05.02 RM 2.286, Segment 21, Site 35 Appendix D U.S. Fish and Wildlife Service Subsurface Sediment Size Distributions Append& D U.S. Fish and Wildlife Service Subsurface Sediment Size Distributions The USFWS collected subsurface sediment data at several sites on the Cedar River in 2001. The table on the next page provides cumulative size distributions (as percent finer than a given size class) for the four subsurface bed material samples collected at the Lower Lions site (RM 12.00). Jones & Stokes processed these samples volumetrically, and a portion of each sample was weighed gravimetrically by USFWS in the field. Distributions obtained using these two methods are not readily combined. Therefore, both volumetric and gravimetric data are shown in the table. In the following table, the sample ID designations "Lions 40" through "Lions 43" are labels assigned by USFWS to each bulk sample they collected. The table also indicates whether the sample was collected ■ near the top of an inner berm ("near") or toward the bottom of the berm/slope ("off'), and ■ whether the bulk sample includes the surface armor ("surface") or a deeper subsurface sample collected at the same place ("subsurface'). Many other samples collected by USFWS in 2001 have not yet been processed. See pebble count data (Table 6 in this report) for point counts of surface size distributions above subsurface samples. USAMCEDAR RIVER GRAVEL Draft Phase 1 Methods and Data Report 04115/02e D-1 Cedar River Grave! Study USFWS Lower Lions Subsurface Sediment Data, River Mile 12.00, Segment 12 Sample ID see preceding text for ex lanation Lions 40 near/surface Lions 41 near/subsurface Lions 42 off/surface Lions 43 off/subsurface VOLUMETRIC METHOD Particle Size mm(percent Cumulative Bed Material Size Distributions for Each Site finer than particle size shown in first column 256 100 100 100 100 128 100 100 100 100 64 100 100 81 100 31.5 73 76 38 69 16 41 52 22 39 8 22 34 12 23 4 11 20 7 15 2 4 10 4 10 1 1 0 0 1 GRAVIMETRIC METHOD Particle Size mm Weight Measured for Each Class in Field rams 256 0 0 0 0 128 10082 3547 11987 9193 64 7668 4444 4882 978 53 4600 305 3230 1080 32 637 0 376 170 Total 22987 8296 20475 11421 Particle Size mm Percent of Sample in Each Size Class 256 0.0 0.0 0.0 0.0 128 43.9 42.8 58.5 80.5 64 33.4 53.6 23.8 8.6 53 20.0 3.7 15.8 9.5 32 2.8 0.0 1.8 1.5 Particle Size mm Cumulative Percent Finer than Particle Size Shown in First Column 256 100.0 100.0 100.0 100.0 128 56.1 57.2 41.5 19.5 64 22.8 3.7 17.6 10.9 53 2.8 0.0 1.8 1.5 32 0.0 0.0 0.0 0.0 USACE/CEDAR RIVER GRAVEL Draft Phase 1 Methods and Data Report 04/15/02e D-2 Cedar River Gravel Study Appendix E Fine Sediment Data Sources Appendix E Fine Sediment Data Sources Cedar River Current and Future Conditions Report (King County 1993) This report is the most complete source of data found regarding sediment recruitment, transport, and storage, including fine sediment. The fourth chapter of this document describes in detail the erosion and deposition of stream and river channel sediments. Fine sediment is not a primary objective of the report and no fine sediment distributions are reported. However, the report is helpful in understanding the sources and fate of sediments and will aid the development of a sediment budget in Phase 2. Key points are summarized below. Sediments in the mainstem Cedar River are derived from three sources. They can be transported from the basin upstream of Landsburg dam (above Segment 1), delivered from tributary streams, or deposited directly to the channel through the erosion of channel banks and riverside cliffs. Chester Morse dam and the Masonry dam trap almost all sediment from the upper 78 square miles of the Cedar River watershed. Sediment delivered to the Cedar River downstream of these dams and transported as far as Landsburg is often detained behind the diversion dam operated by Seattle Public Utilities. Sediments are reentrained and transported downstream underneath dam gates when the gates are opened during annual forebay cleaning and during high -turbidity events. Based on estimates adapted from the Snoqualmie River basin (adapted from Nelson [ 1971 ] in King County [1993]), about 22,000 tons of sand and silt are transported as suspended sediment between Masonry dam and Landsburg dam each year. It is estimated another 2,200 tons of sand and gravel are transported as bedload each year. Based on forebay cleaning and dredging of sediments upstream of Landsburg dam, less than 5% of the river's sediment is removed at Landsburg, leaving 95% to continue downstream when water diversion is temporarily suspended. The tributaries with the most severe erosion and the greatest potential for accelerated sediment production enter the Cedar River downstream of Maple Valley (from approximately RM 16.5 to 2.3, and in Segments 8 to 21). Nearly all of these channels are located within ravines that show some evidence of downcutting in response to increased streamflows associated with high - density developments. In fact, flood flows have increased such that predevelopment 10-year floods occur more frequently than every 2 years in one-third of tributaries modeled during that study. Channel incision has accelerated the delivery and accumulation of coarse sediment in alluvial fans where these steep channels meet the valley floor. However, much of the fine sediment (primarily sands) can be assumed to reach the mainstem. USACE/CEDAR RIVER GRAVEL Draft Phase 1 Methods and Data Report owns/oze E-1 Cedar River Gravel Study Tributaries between Maple Valley and the Landsburg diversion dam (from approximately RM 16.5 to 21.7, and in Segments 3 to 7) are situated on permeable soils and gentle slopes that developed in recessional outwash deposits. Development -induced runoff is also minor but increasing with recent development southeast of Maple Valley. Natural tributary channels have minor erosion problems, if any. On the other hand, the Walsh Lake Diversion channel was relocated to enter the Cedar River downstream of the Landsburg diversion dam in the mid- 1920s. It has since downcut through recessional outwash and older glacial sediments, forming vertical canyon walls that are 30 to 40 feet high with failures that have been active for 40 years. The channel has delivered large amounts of fine and coarse sediment to the Cedar River. Several tributaries were considered very unstable channels as a result of flow increases and as evidenced from channel incision and continued sediment generation. These streams include the Walsh Lake Diversion channel and Ginger, Madsen, Molasses, and Maplewood Creeks. Five then -stable tributaries were identified as having potential for severe erosion problems based on modeling of future flood flow increases. These drainages include Cedar Hills, Dorre Don, Rock Creek, North Fork Taylor Creek, and Webster Lake. Only 5 of approximately 26 tributaries deliver most of their coarse sediment load to the mainstem of the Cedar River, including Rock, Ginger, Peterson, and Molasses Creeks, and the Walsh Lake Diversion channel. The other tributaries store coarse sediment in alluvial fans at the toes of valley walls. However, as described earlier, all tributaries can be assumed to deliver large amounts of sand and finer sediments to the Cedar River. Most coarse sediment in the Cedar River is probably derived from eroding cliffs and stream banks (King County 1993). Although sediment recruitment from these sources occurs nearly continuously at small rates, most occurs in infrequent mass wasting of cliffs that deliver large quantities of sediment to the river very rapidly. Because of the complex glacial stratigraphy, the cliffs most prone to large landslides are found in the Maplewood and Dorre Don areas (Segments 18 to 21, and 7, respectively; RM 5.2 to 2.3, and near 17.3, respectively). An earth slide and flow associated with the Nisqually earthquake occurred on February 28, 2001 in Maplewood Segment 18. This event resulted in the introduction of 200 to 300 in of sediment from colluvial hillslope deposits as well as recruitment of alluvial floodplain sediments in the channel avulsion (USGS 2001). A significant fine sediment component is included in the debris associated with episodic landslides. In the mainstem Cedar River downstream of the Landsburg diversion dam, levees and bank revetments constructed to reduce channel migration have resulted in a narrower channel with fewer sites available for sediment deposition and storage. The capacity of the Cedar River to transport sediment is generally thought to exceed its supply for most of its length. In the Renton segments (especially below RM 2.0), where capacity to transport sediment is reduced and the channel aggrades, less than one-half of the total sediment load is deposited. The remainder is deposited in the delta building downstream of the mouth at Lake Washington. Periodic dredging of the "Renton reach" was discontinued in about 1982, but occurred again in 1998 in the lower 1.25 miles of the river. Gravel augmentation at RM 22.0 is a mitigation requirement for fisheries impacts resulting from this recent dredging effort. USACE/CEDAR RIVER GRAVEL Draft Phase 1 Methods and Data Report 04/15/02e E-2 Cedar River Gravel Study Sites where erosion and sediment recruitment rates are problematic are included in Appendix A of the Current and Future Conditions Report (King County 1993). In summary, King County (1993) characterizes bed material distributions and develops estimates of sediment transport largely in support of a feasibility study of flood mitigation alternatives. It concludes that the capacity for sediment transport exceeds that of sediment supply (i.e., the river is "sediment starved"). Flood problems are therefore not an issue of excessive sediments, but rather of reduction in sediment storage and processing associated with development of floodprone areas. The study identifies problematic erosion areas at least in part to identify coarse sediment sources. Because transport capacity exceeds supply, fine sediments are assumed to be transported to the Renton reach and Lake Washington delta, and fine sediment accumulations, whether local or widespread, temporary or persistent, are not identified. Salmon and Steelhead Habitat Limiting Factors Water Resource Inventory for WRIA 8 (Kerwin 2001) This report was reviewed for recent documentation of fine sediment sources and areas where fine sediment might be identified as limiting salmon and steelhead production. However, the report relied heavily on the Cedar River Current and Future Conditions Report (King County 1993) and provided little new information for the Cedar River downstream of Landsburg. Kerwin (2001) translates sediment and other channel and fisheries information presented in King County (1993) into habitat quality. Taylor Creek, Peterson Creek, and Rock Creek are said to provide good to excellent habitat, but no reference is made to fine sediment. Peterson Creek is identified in King County (1993) as a large tributary source of coarse (and fine) sediment, but this apparently has not significantly limited the quantity or quality of habitat in the system. With its negligible erosion problems (King County 1993), Rock Creek is considered to be among the best salmon and steelhead habitat in western King County (Kerwin 2001). The limiting factors report identifies habitat reductions in Madsen, Molasses, and Maplewood Creeks as a result of a number of urban factors, including excessive sediment accumulations. Despite its historic downcutting and continued unraveling of steep sideslopes, the Walsh Lake Diversion channel maintains some salmonid use. Habitat is rated fair and is considered good in some areas. The influence of fine sediment deposition as a factor of salmonid decline on the mainstem Cedar River is unknown (Kerwin 2001). Although the upper Cedar River is generally outside of the study area of this project (except for Segments 1 and 2), it is interesting to identify sediment and habitat conditions reported for the mainstem and a portion of the watershed with no recent and no urban disturbances (most recent timber harvest was in the 1960s). Kerwin (2001) reports that from Landsburg to Cedar Falls, channel substrates are typically large, and less than 5% of the active channel area is composed of channel bars. Spawning areas are abundant, associated with glides, pool tails, and channel margins. Gravel deposits are rarely embedded or compacted. Substrate is even larger in the canyon and chutes in the 2 miles between Cedar Falls and Masonry dam. USACE/CEDAR RIVER GRAVEL Draft Phase I Methods and Data Report 04/15i02e E-3 Cedar River Gravel Study Tributaries to the upper Cedar River include Rock Creek, Williams Creek, Steele Creek, and Taylor Creek. The former three streams will be accessible to anadromous salmonids once passage at the Landsburg dam is constructed (Kerwin 2001). Rock Creek, south of Walsh Lake and adjacent the Walsh Lake Diversion channel, is low gradient and unconfined with associated riparian wetlands. It is a natural deposition zone and is locally braided with extensive gravel bars. Gravels dominate the bed material, but fine sediment areas are common in low velocity reaches. This stream should not be confused with the Rock Creek channel whose confluence with the Cedar River is in Segment 6 at RM 18.517. Williams Creek is reported to be similar to Rock Creek, but fine sediment or bed material composition is not described. In Steele Creek, fine sediment is a common part of the channel bed, despite a high gradient, because of the geologic surface over which the channel flows. The lower mainstem of Taylor Creek is a steep confined, boulder step -pool stream with barriers upstream of RM 0.2. Upstream of this lower segment, Taylor Creek and its tributaries show evidence of considerable delivery of sediment from upper subbasins, including debris flows, mass wasting events, channel aggradation, widening and braiding, and bar migration. Factors Affecting Chinook Populations, Background Report (Weitkamp et al. 2000) The authors of this report rank sedimentation as "high" with respect to impacts on Chinook embryo incubation for the entire Cedar/Sammamish watershed (WRIA 8). However, they indicate only "some" certainty because there is little information on how sedimentation has affected Chinook salmon. They simply indicate that land use activities influence sediment loading into spawning streams. No data are provided regarding fine sediment accumulations in stream and river beds, and no attempt is made to distinguish conditions in the Cedar River from other streams in WRIA 8. USACFJCEDAR RIVER GRAVEL E-4 Draft Phase 1 Methods and Data Report 04/15/02e Cedar River Grave( Stud), Appendix F Photographs for Individual Survey Sites Photographs for all data collection sites are presented in order of decreasing river mile (from upstream to downstream). Segment and site information are also presented in each caption. Tributary photographs, if any, are placed by the river mile of their confluence with the mainstem Cedar River. .�- � s_{ ��� � �a 1 ;� :� � _ �.� �ifr _ -a -_ _ - ; � � r -,. - - x ��_. � � � �� c ��� - .=aY ="�- •�_ .._. .. ---•• . . _ _ �` � v� - _ • _ _ � fV ��4 _ �,i�� �aai � t _ arm _ _.. _ls � � _ � F a e '- ` � �3�1�"� �..- � ..: _ .,.ter � - .-� _ i.%- t.-s4.... .. a . I RM 23.155, Segment 2, Site 3, Downstream RM 23.155, Segment 2, Site 3, Right Bank 77, RM 22.945, Segment 2, Site 4, Upstream RM 22.945, Segment 2, Site 4, Downstream S 1 Y e � �.. ' 2i. _ ac Zvi • 'a .;Y� f4r� �� a � '�^:+•C 1 �S�r Y-r �� ., - _ •..�y t Ate.-� MLI .'yam e�,�"-� � - !�,'�°-�_� ; ,�,;-. - 'z^'` •_�-�^ ._-. -. r; Y 4` � �'• ` � `ice a +Y�,�` t.. _ . � t ` , Z�. � t � _ ..� � . - tF"41C ;_ - .x `'..fir` .• _ mot. - INM w _44 v Elf Ls t Y �s• i T y �`' � ` �,'+• v �3"'" Wit': � � ; f - l Y�- i�.yj2 ayc;• to Mo Y-v� T cF f ..:� - . - � �'�`+�-'��''r'{'��.�.z �'y' t�� ,; t �,�x = } � _� ram, _• _ RM 21.261, Segment 4, Site 7, Left Bank A-4 r "15; -- 41 4 WW Si:U - RM 21.261, Segment 4, Site 7, Right Bank RM 20.493, Segment 5, Site 8, Upstream RM 20.493, Segment 5, Site 8, Downstream RM 20.493, Segment 5, Site 8, Left Bank RM 20.493, Segment 5, Site 8, Right Bank 75 V ? -fj 5� 10 RM 19.865, Segment 5, Site 9, Left Bank RM 19.865, Segment 5, Site 9, Right Bank tg as _•"W'. W =�iYe=�lr RM 18.546, Segment 6, Site 10, Left Bank RM 18.546, Segment 6, Site 10, Right Bank RM 18.546, Segment 6, Site 10, Up and Right RM 18.517, Rock Creek RM 18,145, Segment 6, Site 11, Upstream No Photo Available RM 18.145, Segment 6, Site 11, Downstream - y is J pF' < W. -.. f€ib �'/�s��;�� •s. " �ql� ,s� 'l: �' _Je 2 hy�s'e'�I _ �n•v ^l- 'R&C.�, .:ate_-+ti• EY � � Y .1 i� r+ir.. .. _ � _ r. �. � „M _ _ _ �. _ _ _ _ 1 �� .` � _ '�i~'fit � �'{x � •� +� � - �. ,.K � � . _. _ _ __ _ c - ,,,�, is � d rt, �' .�; �.�- . �y r , -� - - �' . ��' ,. �,,. .n� � _ � _ ��`��'-fir.:=:�7x. _a � � �� � :e= �� " .,-t�s. ...�- z� ;- � ��~ �-�--- ' y .. ;�� :� �'. - r! � �� r1 �;:�rrr. - � s�.r�l� � . _ ` .,.: t_ .1 on Jo- �p � Y '+ y q� � r �;I Es Ir 4fZ Fri •, Y y1:f � c� tq .� � Lam.. -� - fir- �'- �• � �.�._-,,� � _ � f = �'� 1 `�;e�.-���fi`-_• .,.sue.. _ ice.+ -- -._� �. y y, j r _ - -� _�'o'�� g• Vie- _ r RM 14.575, Segment 10, Site 18, Upstream RM 14.575, Segment 10, Site 18, Downstream RM 14.012, Segment 11, Site 19, Upstream RM 14.012, Segment 11, Site 19, Upstream an _ tl r 1� III MM till .Nil 3 _ 61 �y3� r�,y�'` +r . v .. _=�� _ '..i1��-a�v A.I u. .. � �• ti Lc a�T .t `48NCr�_ -' s: 3 �✓._t - Y � '� .^?F � 2 �• SSA � .'R Sh � +: Y` RM 13.208, Segment 11, Site 20, Left Bank RM 13.208, Segment 11, Site 20, Right Bank - eF S M 7�--xkl i .e. - 3•'- <_ - `- 3 � -,r � #sue .� �, 'K°�.. � !�, r' T-- f . s'Z / jit rs-=• w U-0 A -- i- �, '— •�x� �•;. rA � ems. s � ,yam_ .. �" �': y a � - rr Mat i y RM 11.366, Segment 13, Site 23, Left Bank a' a --se .mow �' � �-• �. '� �,. .: �'��r YET. �, �Y ��y `'� "S-' ♦''�y �. `3"���. ,� +''ram •� .'� RM 11.366, Segment 13, Site 23, Right Bank _ ) -' i/ '� MELT T-- -T •�` -y - . y - jtp3aa74 ��•� r S •� �.Y Ti �` {. y .�,• �. . i iVlit( r ' ! 1. sa - '•==^tea _ ^� f 'r -i` •".Z r � � :f !'` fb •? _ .tap " s ` k� sic f • ",`tom 9+i - ft-.- ' ! .r ..- • - .` t1 ik 41 s. . tom. - e _ 4 .!' :�_ W--m06 i • �. '�-y F OF T4'lmj."'w 'q_ ' m Do 14 :1' - �' �. A'i�J f�e4 R %� .�d i� i fir. .•! ��j�{ r>• � , fY f1,3 Y a r - .C-� '• £�S � J - - 9 - �- fr •Ji. ���t� ��t -~'a �,r � v:. �` •s' "plc � c'}' a � R l i f _._- - •. - 1.. _., _:a `�.,:;�- _ ...sue. �:,.� A`as. - _ _ ..+ - -_-7M . . • m .� 6w; It . � _-� .,�•� �-� �y�- .�i�.�r.�- .ems' -� ''�'�•��` " � :r: ` pig, `.4 � xlwwr 17 RR ME_ z s Prop 64, 1 ���,.�P'rJ� �' - _ - _ _—'--!^s• - + ash. 4 T rN RM 8.193, Segment 16, Site 28, Left Bank RM 8.193, Segment 16, Site 28, Right Bank RM 7.395, Segment 16, Site 29, Upstream RM 7.395, Segment 16, Site 29, Downstream RM 7.395, Segment 16, Site 29,. Left Bank RM 7.395, Segment 16, Site 29, Right Bank f ROw - F.P.Mr Met k- MR L •� .r „tea` §f� X • 'ti- - i `- a lot -it a.F �_ �+.�� ._\ y\ � ..+,�¢F�� �•; � �.. `ice` - (�a {'� 5P. �!• fit- ! �s � T. >�i. 4�:! • ,y 4 L'v y R 'AM » RM 4.702, Segment 19, Site 32, Upstream Left RM 4.702, Segment 19, Site 32, Upstream Right RM 4.702, Segment 19, Site 32, Downstream RM 4.702, Segment 19, Site 32, Left Bank RM 4.702, Segment 19, Site 32, Right Bank 4, 4W -OF N RM 4.380, Segment 20, Site 33, Upstream RM 4.380, Segment 20, Site 33, Downstream ti RM 3.548, Segment 20, Site 34, Upstream RM 3.548, Segment 20, Site 34, Downstream RM 3.548, Segment 20, Site 34, Left Bank RM 3.548, Segment 20, Site 34, Ri,ht Bank s RM 2.286, Segment 21, Site 35, Left Bank RM 2.286, Segment 21, Site 35, Right Bank Appendix G Maps for Cedar River Gravel Study Phase 1 Methods and Data Report Key Map # Study Segments River ;Miles 1 1 —4 23.6-21.8 2 4-5 21.8-19.9 3 5-7 19.9 — 17.5 4 7-8 17.5-16.0 5 8 — 10 16.0 — 14.6 6 10— 11 14.6— 13.4 7 11 — 12 13.4 — 12.1 8 12— 14 12.1 — 10.5 9 14— 16 10.5 — 93 10 16 9.3 — 7.7 11 16— 17 7.7-6.3 12 17 — 18 6.3 — 5.0 13 18-20 5.0-3.5 14 20-21 3.5-1.9 15 21-22 1.9-0.9 16 22 0.9 — 0.0 Ya \n wi max: a; r r� 1360000 1362000 y�' 11► A �. r',, ,."ae� h .MYiiF�if4` L1 j* „►`'.ir��;. � �T• r J.a 4"���j�.�t� �� � ",rl+.�frr,}7i. � 'h•'r i f - '!I 'sir. �! �^t ��!y�! � � : .s�"r� �• �d/'�#d�'.' � 'rid Y � :.L" ,�, •��'�''�`• r H � rn M�1 ♦.� e. t�ryiA�'� � ,R s�� °* v, r , ,.. _ � t . rt •- .' w r- ;V�;�M�1 ��� .r k •► ' F�r' .i' j,• �.�, '.Ar rt� '..s� ,• fC w,,�.� . �r � +Cg�sy.f t !'�st�' f 4 �, � :�� r"1 .i' rr l �4� i.`•♦ S� `�,, ,�.� ' R"•A -* "�1' vj1 ii f.i� ' i's, t t' a ° �`P w X ., may• •k�''� 23.3 5 23 3 1 AZ �' i fi�. , E+ r�..i r t` i`�r• it Z3 1 5It `♦ ♦ . 'R'�r+' ` �r ' Nk S w A F Z ••t� �j it tit+ � s'�7 ��• � ""� `ti._�►�7e �.. �:�� a���-.t♦f--a'!i r gip.}.�v •1! r ..'� yt,.f' �t �,a r_. 2 7_ywj P� Y.��✓•�'�r1r' t.♦ p•►,►. Ci -� ..t, IN'* .Ti-+•. �:� r• ♦ 1► l! n •• '` F r_; 1 e'� �!��f! �� . 1 j� t,• "' .its V�y�� _' rf . ' 7� ♦hi xr',CX♦ rc', �, ,e ,� ' �I �: � I+yr.� -F.. /� r r �"� t i � `..l'Y }�"��k'�.`-�• r4 ,� x. . r. + 1360000 1362000 Cedar Rlvv, Gravei Study SampHng Plan Fpbrruaoy 5, 2002 Sheet I of 16 LEGEND Goss Sections and Pebble Courts • Existing Flood Study Cross Section (King County) • Existing Flood Study Cross Section (Renton) 2.286 Existing Flood Study Cross Section Selected for Survey (River Mite Denoted) 2.286 New Cross Section Added In This Study (River Mile Denoted) - Alternative, aJnsurveyed Flood Study Cross Sections With Good Spawning Gravel Sediment Data Existing Surface Or Subsurface Sediment Data 2.286 Additional Surficial Pebble Counts In This Study (River Mile Denoted) 2.286 Subsurface Sediment Sampling In This Study (River Mile Denoted) Redd Densities By River Mile Steelhead Chinook 0.0 - 4.0 0.0 - 4.0 4.1 - 6.0 4.1 - 6.0 6.1 - 8.0 6.1 - 8.0 8.1 - 10.0 8.1 - 10.0 Q : 10.1 > 10.1 1999/2000 Chinook Redd Locations �® Segment Breaks Segment Number ,90 /1 ©C Segment Gradient and Confinement King County Managed Flood Facilities Source: King County Department of Natural Resources, 2000. King County GIS Center, 2000. N 250 0 250 500 750 1000 Feet 50 0 50 100 150 Meters Scale: 1" = 500 feet �`;� Jones & Stokes 4 4�� 16A P 1354000 yr r f •' • l i w -e �47 . R I 13'SRnnn , �4 r F N4 w r• f l .IL may- � ,9. � is"9';/w ; �. �. •� 11 �. •st• G�i � irr� . v.•''�• ♦ •i • . Ale to r - to . �f t r �'. � �► CedarRiver Graved Study SampUng Plan February 5, 2C32 Sheet 2 of 16 LEGEND Cross Sections and Pebble Counts • Existing Flood Study Cross Section (King County) • Existing Flood Study Cross Section (Renton) 2.286 Existing Flood Study Cross Section Selected for Survey (River Mile Denoted) 2.286 New Cross Section Added In This Study (River Mile Denoted) AlternativeUnsurveyed Flood Study Cross Sections VAih Good Spawning Gravel Sediment Data Existing Surface Or Subsurface Sediment Data 2.286 Additional Surficial Pebble Counts In This Study (River We Denoted) 2.286 - Subsurface Sediment Sampling In This Study (River Mile Denoted) Redd Densildes By River AA4ie Steeftad Chinook 0.0 - 4.0 0.0 - 4.0 4.1 - 6.0 4.1 - 6.0 6.1 - 8.0 6.1 - 8.0 ® 8.1-10.0 j 8.1-10.0 Q > 10.1 > 10.1 1999/2000 Chinook Redd Locations WSegment Breaks II Segment Number 0,, 70C Segment Gradient and Confinement King County Managed Flood Facilities Source: King County Department of Natural Resources, 2000. King County GIS Center, 2000. N 250 0 250 500 750 1000 Feet 50 0 50 100 150 Meters �iaf -- Scale: 1" = 500 feet Jones & Stokes IJUGUUU 1356000 1346000 1348000 1350000 f% S J t or Ir Ir I. r' t ;�,� •--t' ♦ _ Y•t mo o' Y ",C "�� ��i I` ,� `K44 VP z r wf 42~,J r-• r �i•r ;� Ti ;./ _}Jr M` f ,yj♦.► �. � � e .• tjG t �! � •J /' •�. a •ll,�•� r pt • }• IL f / r• ° Hof? •., M!'''�,�, .., r �"�. 7f^' .•r ,.� �* "�-C' ' +g. ' f N. SON J 55 62 -- - 40 _ r 1 •r *011 ���� � ��./tcf�i+_ •,, � • r�� •� .yeas_ .�.., r s r A 00 •F Qp%N E� s 14 1 � � � + J � �('► �+�►�, 4% � � i,PF+jM.. +►.- :...may rr--cw .. � � :"li.•�irt@s.� r VL N g Cedar River Gravel Study SampHng plan February 5, 2002 Sheet 3 ®f 16 LEGEND Cross Sections and Pebble Counts • Existing Flood Study Cross Section (King County) • Existing Flood Study Cross Section (Renton) 286 Existing Flood Study Cross Section Selected for Survey (River Mile Denoted) 2.286 New Cross Section Added In This Study (River Mile Denoted) -,v Alternative, Unsurveyed Flood Study Cross Sections With Good Spawning Gravel Sediment Data Existing Surface Or Subsurface Sediment Data 2.286 Additional Surficial Pebble Counts In This Study (River Mile Denoted) l '?8 Subsurface Sediment Sampling In This Study (River Mile Denoted) Redd Densities By River Mile Steelhead Chinook 0.0 - 4.0 0.0 - 4.0 4.1 - 6.0 4.1 - 6.0 6.1 - 8.0 6.1 - 8.0 ® 8.1-10.0 8.1-16.0 10.1 a 10.1 1999/2000 Chinook Redd Locations Segment Breaks Segment Number (0a 70C Segment Gradient and Confinement King County Managed Flood Facilities Source: King County Department of Natural Resources, 2000. King County GIS Center, 2000. N 250 0 250 500 750 1000 Feet 50 0 50 100 150 Meters Scale: 1" = 50C Feet Jones & Stokes 1346000 1 IN I I• 1342000 1344000 11ARnnn it r s. ems/ Y't •t �: r : ! ' + �i,. �_ � �t15.V4'9 �+ tl �. �. r�1�"�.:^� d•-..fro w _ ' Y,�, y.; �.` ej'. "r. • fix- t' •��,,, .r » SIr ,, ti el e �I��-w go • - ,eel►• 5 �. �' ' �. y '`' T� 'fir, ♦ 1 � �. � _ .. � 66 TVqt 40 ' .. ��`7f �i ,Q • � ��, ' ..1 i;•� . t � jii'' •s r, ; jaw C• �+I�' � jy��� ^ j�,1' �,��.'4��',.R�- _ *, rT,}��'r . r rir . r16 rw • vot fj • ,�, r _�� ►rat � _�. ���: 4000 1346MO I• 11 Cedar River Gravel Study SampHng plan February 5, 2002 Sheen: 4 ®f 16 LEGEND Goss Sections and Pebble Counts • Existing Flood Study Cross Section (King County) • Existing Flood Study Cross Section (Renton) 2.286 Existing Flood Study Cross Section Selected for Survey (River Mile Denoted) 2.286 New Cross Section Added In This Study (River Mile Denoted) Alternative, Unsurveyed Flood Study Cross ? Sections With Goad Spawning Gravel Sediment Data Existing Surface Or Subsurface Sediment Data 2.286 Additional Surficial Pebble Counts In This Study ' (River Mile Denoted) 2.286 A Subsurface Sediment Sampling In This Study (River Mile Denoted) Redd EDensittes By Riveir Mile Steelhead Chinook 0.0 - 4.0 0.0 - 4.0 4.1 - 6.0 4.1 - 6.0 6.1 - 8.0 6.1 - 8.0 ® 8.1-10.0 8.1-10.0 10.1 = 10.1 1999/2000 Chinook Redd Locations Segment Breaks Segment Number USo 7 GL Segment Gradient and Confinement King County Managed Flood Facilities Source: King County Department of Natural Resources, 2000. King County GIS Center, 2000. N 250 0 250 500 750 1000 Feet 50 0 50 100 150 Meters u Scale: 1" = 500 feet ��SSS Jones & Stokes 1338000 1340000 0 Y I149nnn • e 11 xlr)�.4 ` 14.757 r y �. 4 qV v J Ir �•-� �.r �, ♦! • j � er � � y , ' ►fir ( .� �'' ��'� � • f' VIA idol �� \ '�~ ' �. �J/7` � �� fit► _ �i".�I - r� •. 'A A _• ry 0.64V M _s F �Y � •x��nnn N ^II 0 CI O pp 0 I I I Cedar Diver Gravel sty Sampling Plan February 5, 2002 Sheet 5 of 16 LEGEND Cross Sections and pebble Counts Existing Flood Study Cross Section (King County) Existing Flood Study Cross Section (Renton) ".286 Fxishng Flood Study Cross Section Selected for Survey (River Mile Denoted) 2.286 New Cross Section Added In This Study (River Mile Denoted) Alternative, Unsurveyed Flood Study Cross Sections With Good Spawning Gravel Sediment Data I Existing Surface Or Subsurface Sediment Data 2.286 Additional Surficial Pebble Counts In This Study (River Mile Denoted) 2.286 x Subsurface Sediment Sampling In This Study (River Mile Denoted) Redd iDensites By River We Steelhead Chinook 0.0 - 4.0 0.0 - 4.0 4.1 - 6.0 4.1 - 6.0 6.1 - 8.0 6.1 - 8.0 8.1-10.0 != 8.1-10.0 2 10.1 2 10.1 1999/2000 Chinook Redd Locations �® Segment Breaks Segment Number ®a 70C Segment Gradient and Confinement King County Managed Flood Facilities Source: King County Department of Natural Resources, 2000, King County GIS Center, 2000. N I 250 0 250 500 750 1000 Feet 50 0 50 100 150 Meters Scale: 1" = 500 feet >`�5 Jones & Stokes 1338000 1340000 1 zA?nnn Ar pw � .. _,fir .. •� 1338000 j rxs v ! �.+OPP, i 17• 1 r. _ a �;. j, q �h j '' T17p'. •r�IL 40, r. _. 41 • ; ♦ � �� A, -ram ` V. cam,*.fir- L. % f 14A7nnn Color River Gravel Study samplin- Plan February 5, 2CJ2 Sheet 6 of 16 UGEND -- Cross Sections and pebble Counts i Existing Flood Study Cross Section (King County) Existing Flood Study Cross Section (Renton) 2.286 ° Existing Flood Study Cross Section Selected for Survey (River Mile Denoted) 2.286 New Cross Section Added In This Study (River Mile Denoted) Alternative, Unsurveyed Flood Study Cross Sections With Good Spawning Gravel Sediment Data Existing Surface Or Subsurface Sediment Data 2.286 Additional Surficiat Pebble Counts In This Study (River Mile Denoted) 2.286 Subsurface Sediment Sampling In This Study (River Mile Denoted) Redd Densities By Qiiver We Steelhead Chinook 0.0 - 4.0 0.0 - 4.0 4.1 -6.0 % 4.1 -6.0 6.1 -8.0 %j 6.1 -8.0 8.1 -10.0 8.1 -10.0 210.1 a10.1 1999/2000 Chinook Redd Locations �® Segment Breaks Segment Number ,/, (: Segment Gradient and Confinement King County Managed Flood Facilities Source: King County Department of Natural. Resources, 2000. King County GIS Center, 2000. n 250 0 250 500 750 1000 Feet 50 0 50 100 150 Meters Scale: 1" = 500 feet 555 Jones & Stokes I• i f t 1:.r r• t ' •,�` � `�'� `•''fit ,,, , Aw Al �. • ,, o ,�` � �y ' .. "yam � ' ° !b t' ■ At w alp � J ' - • + , ! • i .��. - r Pr,71 71- :1 Cedar River Gravel Study sampfing Flan February 5➢ 2C)2 Sheet 7 of 16 LEGEND Cross Sections and Pebble Counts Existing Flood Study Cross Section (King County) e Existing Flood Study Cross Section (Renton) 2.286 Existing Flood Study Cross Section Selected for Survey (River Mile Denoted) New Cross Section Added In This Study (River Mile Denoted) A , Alternative, Unsurveyed Flood Study Cross Sections NMth Good Spawning Gravel Sediment Data Existing Surface Or Subsurface Sediment Data 2.286 Additional Surficial Pebble Counts In This Study (River Mile Denoted) 2. 286 Subsurface Sediment Sampling In This Study (River Mile Denoted) Redd Densities By River Mile Steelhead Chinook 0.0 - 4.0 0.0 - 4.0 4.1 -6.0 % 4.1 -6.0 6.1-8.0 /. 6.1-8.0 8.1-10.0 8.1-10.0 > 10.1 > 10.1 1999/2000 Chinook Redd Locations �® Segment Breaks j Segment Number 0. 0 0 Segment Gradient and Confinement King County Managed Flood Facilities Source: King County Department of Natural Resources, 2000. King County GIS Center, 2000. N 250 0 250 500 750 1000 Feet ^� 50 0 50 100 150 Meters 3150000 Im Jones & Stokes k� !. J >�.-:. ti. ' � � .. •�. � ''• ter •, i ! - • 46 -t-0 d •� o � [ 0 11i .1i`•i� N N 'K•1p�''J 1334000 13360GO r• �l T r ` � t� a� ¢` 40 All A r o r 6 �'. i,•r i � �.� i.1 ii - .Y.44 71�.: .. -JI S12 ®.331J 1338000 p °T i ti 1338000 TF 11 Cedar Neer Gravy Study sampflng Nan February 5, 2002 Sheet a of 16 LEGEND Cross Sections and Pebble Counts Existing Flood Study Cross Section (King County) ^ �QQLLExisting Flood Study Cross Section (Renton) /.2QG Existing Flood Study Cross Section Selected for Survey (River Mile Denoted) 2.286 New Cross Section Added In This Study (River Mile Denoted) ��- Alternative, Unsurveyed Flood Study Cross Sections With Good Spawning Gravel Sediment Data Existing Surface Or Subsurface Sediment Data 2.286 Additional Surficial Pebble Counts In This Study (River Mile Denoted) Subsurface Sediment Sampling In This Study (River Mile Denoted) Redd Densities By River We Steelhead Chinook 0.0 - 4.0 0.0 - 4.0 4.1 - 6.0 4.1 - 6.0 6.1 - 8.0 6.1 - 8.0 8.1-10.0 8.1-10.0 > 10.1 > 10.1 1999/2000 Chinook Redd Locations Segment Breaks Segment Number ©o 70C Segment Gradient and Confinement King County Managed Flood Facilities Source: King County Department of Natural Resources, 2000. King County GIS Center, 2000. N 250 0 250 500 750 1000 Feet 50 0 50 100 150 Meters Scale: 1" = 500 feet >$ A Jones & Stokes 1330000 A tit 1334000 1-- 0.3 i > a a 10.017 ' POI I ate. a1Frw� �' u'��ii`3t`ir• V, AAr- E � 'tfJr . �I Cedar River Gravel Study Sampling Plan February 5, 2C32 Sheet 9 ®f 16 LEGEND Cross Sections and Pebble Counts Existing Flood Study Cross Section (King County) Existing Flood Study Cross Section (Renton) 2.286 Existing Flood Study Cross Section Selected for Survey (River Mile Denoted) 2.286 New Cross Section Added In This Study (River Mile Denoted) Alternative, Unsurveyed Flood Study Cross Sections With Good Spawning Gravel Sechment Data Existing Surface Or Subsurface Sediment Data 2.286 Additional Surficial Pebble Counts In This Study (River Mile Denoted) Subsurface Sediment Sampling In This Study (River Mile Denoted) Redd Densities By iRuw Mice Steelhead Chinook 0.0 - 4.0 0.0 - 4.0 4.1 - 6.0 4.1 - 6.0 6.1 - 8.0 6.1 - 8.0 F 8.1 -10.0 j 8.1 -10.0 > 10.1 > 10.1 1999/2000 Chinook Redd Locations Segment Breaks Segment Number 0. 70C Segment Gradient and Confinement King County Managed Flood Facilities Source: King County Department of Natural Resources, 2000. King County GIS Center, 2000. N 250 0 250 500 750 1000 Feet 50 0 50 100 150 Meters Scale: 1" = 500 feet 1334000 Jones `X Stokes 1328000 I L 1330000 tT"�?nnn ��,WV r�sML. WL, r 1 � ♦ ry J N 0 g 31 Cedar River Gravel Study Sampling Plan February 59 22002 Sheet 10 ®f 16 LEGEND Cross Sections and Pebble Counts Existing Flood Study Cross Section (King County) Existing Flood Study Cross Section (Renton) 2.286 Existing Flood Study Cross Section Selected for Survey (River Mile Denoted) 2.286 New Cross Section Added In This Study (River Mite Denoted) Alternative, Unsurveyed Flood Study Cross Sections Wirth Good Spawning Gravel Sechment Data Existing Surface Or Subsurface Sediment Data 2.286 Additional Surficiat Pebble Counts In This Study (River Mile Denoted) 2.286 ® Subsurface Sediment Sampling In This Study (River Mile Denoted) Redd Densities By River Mile Steethead Chinook 0.0 - 4.0 0.0 - 4.0 4.1 -6.0 4.1 -6.0 6.1 -8.0 // 6.1 -8.0 8.1 -10.0 8.1 -10.0 > 10.1 > 10.1 1999/2000 Chinook Redd Locations Segment Breaks Segment Number 0o 0C Segment Gradient and Confinement King County Managed Flood Facilities Source: King County Department of Natural Resources, 2000. King County US Center, 2000. N 250 0 250 500 750 1000 Feet 50 0 50 100 150 Meters Scale: 1" = 500 feet �%P� Jones & Stokes 1.53VVVV 1332000 Cedar River Gravad Study Sampling plan February 59 2C32 St et II of56 LEGEND Cross Sections and IPeWe Counts 6 Existing Flood Study Cross Section (King County) 6 Existing Flood Study Cross Section (Renton) 2.286 Existing Flood Study Cross Section Selected for Survey (River Mile Denoted) 2.286 New Cross Section Added In This Study (River Mile Denoted) Alternative, Unsurveyed Flood Study Cross Sections With Goad Spawning Gravel Sediment Data Existing Surface Or Subsurface Sediment Data 2.286 Additional Surficial Pebble Counts In This Study (River Mile Denoted) 2.286 Subsurface Sediment Sampling In This Study (River Mile Denoted) Redd Densities By River Mile Steelhead Chinook 0.0 - 4.0 0.0 - 4.0 4.1 - 6.0 4.1 - 6.0 6.1 - 8.0 6.1 - 8.0 ® 8.1 -10.0 8.1 -10.0 M 2 10.1 2 10.1 1999/2000 Chinook Redd Locations Segment Breaks Segment Number I U,, k UL Segment Gradient and Confinement King County Managed Flood Facilities Source: King County Department of Natural Resources, 2000. King County GIS Center, 2000. N 25C 0 250 500 750 1000 Feet 50 0 50 100 150 Meters Scale: 1" - 500 feet Jones & Stokes 1316000 131800Q 1320000 4.d 1, �` .li .-�. ..� `t► '.1 •U}+ •� •, 0- qr Ise ' ,'` -,� � •r -•�`.�_'� '.%�`. `q Tom^'' � �'�/�, '� r' ' �,: �I .. �.`Z•' '� - { l,� ~!"1• r r••• q -?y' �� ; �•r�e •� } r ^y#.r �+'.�� '� .fit' y ," �. ` „'c�.:;� �' • : �f: 10,715 8v Wit -k r... ,. r , l � l't� �}�, � •'! r,, � �, M. � } ♦ �: r � ,. 1 � P, �.: of �� �... .. � ., , f� •a'(r`�y� }'• �1\ ; 7t o� 'rp..�\ ••.. "r,7 k *f .. r `� ',I•i`+� IS#. . CD Ilk •rl) R 1t 40 4Olt .• �� ♦ (��� �� � ' ti'� '►-'i� sill .�{, • �• .�: ��5� •*jr:�. _�• •�.E,��. •� ••ti '.,�;��� ;'� ,q, �• • •fit, , ,il•" ��� ' , A ,--, p ♦ ';� , _ ''� s � ♦. I�' , �1 '^,_ l '« Zvi _ ^� _��� � �. R . �' p • `��y 3 + yi J`P ♦ ��ith•• .�� "�'y�� _ •r Tex. 1' T r• ♦j ".' "' � 1� `} � / � � ,r ' ^• • , �,�' , '�� ♦�.- R' �lt.r, ��••iily�,r� .� !•� ^y� --� _��{+•'r�� � �,t�jn,. 7•t( ( �•s �',.!rw. /rw. Ap +- ""7 ark `' � 11 ,. '+rA .• . _ • � s' �V r 1316" 1318000 1320000 Cedar River (Graved Study Sarnpiing Plan February 5, 2002 She'et 12. of 16 LEGEND Cross Sections and iPeWe Counts • Existing Float Study Cross Section (King County) • Existing Flood Study Cross Section (Renton) 2.286 Existing Flood Study Cross Section Selected for Survey (River Mile Denoted) 2, 286 New Cross Section Added In This Study (River Mile Denoted) �i..,- Alternative, Unsurveyed Flood Study Cross Sections With Good Spawning Gravel Sediment Data Existing Surface Or Subsurface Sediment Data 2.286 Additional Surficial Pebble Counts In This Study (River Mile Denoted) 2.286 - Subsurface Sediment Sampling In This Study (River Mile Denoted) Redd Deansitdes By River MHe Steelhead Chinook 0.0 - 4.0 0.0 - 4.0 4.1 - 6.0 4.1 - 6.0 6.1 - 8.0 6.1 - 8.0 ® 8.1-10.0 8.1-10.0 ED > 10.1 > 10.1 1999/2000 Chinook Redd Locations ^If Segment Breaks 51 Segment Number JY -1?nP Uo l/ UL Segment Gradient and Confinement King County Managed Flood Facilities Source: King County Department of Natural Resources, 2000. King County GIS Center, 2000. N 250 0 250 500 750 1000 Feet 50 0 50 100 150 Meters —Scale: 1" --- 500 feet .0$ A Jones & Stoke 1312000 1314000 13',6000 .� , , ? c.. ,`. . s � .•» .- �. ti ��.� y, 1 �• r .�. _ ' . . �-, � .. _ ,yam l . "..� pgpgpq - a � • 1 . '� • � .: a'* ` v �. 0 yy,l yy„ !t ti� ! ,. • •� � },, , �..' . � * Y • � i► - '� 4 ` ' � },y,�', I ` i( d 1, 1 , - ` �- .,,t! . r re•, -! . �.. '+i: ..•"•..:. MF q " 40• AV'-} `' � I,, �, ,� � r� I1� Ji 7�• i'r��� �11. �• +(jy��, k1i II: -'� I• -fix•• �? _.'.� .•; it �\ •r\ .I i '•.. y 'I !r� :,\ ` I Ir cr Till A.r�. 'Y ,.. , Al 0,0 • Y• , s, f F W ;JAW t or �► Wr A" S20 50 , . � � `'*•7i � � �l �'\ � �. i —1 .o:• • .. •?t �St;- � � ,fir L •' ` OL 71 �y , � �. ��� +. � . `Z ' ? � ,, tile.• I; ow f 9. 46 f r <�`+►` �.� � s n _ '� ', 'F i ... �•� ' 1�.. ' •• yr -. v � �• � �,� f �r•.� ir '� � ► �,., �^i �' it ��'i x♦ ,'�:+,,,,�+ .��• r� ♦ r� f � `, i k i• ,' �• •' R a ti ff R a= a •"' k,., •� •; ,�: s + ,�� . a��fi `�; xis ` '�' 7i �' � ' � s.`° ' � `s o'� , ; ,` 'f - 4 .` tiT�� p r •!'ki 5�' ''` �.� 7 � 1 �� .,i die. S..L.. v • F ( 1312000 1314000 1316000 Cedar River Graved Study Sampling Man February 5, 2002 Sheet 13 of 16 LEGEND Cross Sections and (Pebble Counts • Existing Flood Study Cross Section )King County) • Existing Flood Study Cross Section (Renton) 2.286 Existing Flood Study Cross Section Selected for Survey (River Mile Denoted) 2.286 New Cross Section Added In This Study (River Mile Denoted) Alternative, Unsurveyed Flood Study Cross Sections With Good Spawning Gravel Sediment Data Existing Surface Or Subsurface Sediment Data 2.286 Additional Surficial Pebble Counts In This Study (River Mile Denoted) 2.286 Subsurface Sediment Sampling In This Study (River Mile Denoted) Redd Densities By River Mile Steelhead Chinook 0.0 - 4.0 0.0 - 4.0 4.1 - 6.0 4.1 - 6.0 6.1 - 8.0 6.1 - 8.0 8.1-10.0 8.1-10.0 , 10.1 > 10.1 1999/2000 Chinook Redd Locations Segment Breaks Segment Number If%a U Ulf Segment Gradient and Confinement King County Managed Flood Facilities Source: King County Department of Natural Resources, 2000. King County GIS Center, 2000. N 250 0 250 500 750 1000 Feet nNiiiiiiiiii 50 0 50 100 150 Meters Scale: 1" = 500 feet 555 Jones & Stokes I me a y�I 1» � _ �� _'�F yam. 11 .• d M f�efi,�T�T r l•'F �N ~ 1 06 Y , , KNI ' � � . a: . .l• � i fir ,�p� .' '�• ,�,` �. • �!`�. -> , • 7 r '"�� '` 4 t` 9"� 1?• .i'j VW ' !' 7 3 M•`1!t� '�� �* 1•�` �. , �'r4 • f `-.t -'wy is -i_I 1 �� 1 * ♦ ;!� '� �' '��i; `.f� 'y \:� { I• 0 Cedar River Gravel Study Sampling Nan February 5, 2002 Sheet 14 of 16 LEGEND Cross Sections and Pebble Counts t Existing Flood Study Cross Section (King County) Existing Flood Study Cross Section (Renton) ,286 °' Existing Flood Study Cross Section Selected for Survey (River Mile Denoted) 2.286 New Cross Section Added In This Study (River Mile Denoted) t - Alternative, Unsurveyed Flood Study Cross Sections With Good Spawning Gravel Sediment Data AExisting Surface Or Subsurface Sediment Data 2.286 Additional Surficial Pebble Counts In This Study (River Mile Denoted) 2.286 - Subsurface Sediment Sampling In This Study (River Mile Denoted) Redd Densutfies By River We Steelhead Chinook 0.0 - 4.0 0.0 - 4.0 4.1 - 6.0 4.1 - 6.0 6.1 - 8.0 6.1 - 8.0 ® 8.1 -10.0 j 8.1 -10.0 > 10.1 210.1 1999/2000 Chinook Redd Locations Segment Breaks Segment Number Igo d UL Segment Gradient and Confinement King County Managed Flood Facilities Source: King County Department of Natural Resources, 2000. King County GIS Center, 2000. N 25C 0 250 500 750 1000 Feet 50 0 50 100 150 Meters Scale: 1" = 500 feet 555 Jones & Stokes 1-z, nnnn i.r F ALI Tt ��� - � - +-- r - r1 rim . - � � aft ar ��'`•i - � ' ' _ _ '. � I,j I ~ � `� ` W r - - _ ' - - - _ — R.- _r r ,. � ...- � i I r- � • .� , •(d,•.�t Ti w... ` 4 / •a I , ti • � +I - �_.. - �' / r. � 1 `%. �� r ( _ 1 1 , .dam r'K �. '' � �;�� � ✓1, —' � � `,'� ��! �. � ft1♦+�� ��! _ •7' � �/.r�� ;•, e: l �.. ir dill Gomm Illa- 1 • •�. r ! '� ♦�- /i ' ter ... i. r 1` � L " _ r � � ' � � � .n jIj • - , I rf ♦ • ,� �T. ti,�h,"-�'1Zi.y, •a ,K• �� •.,��,s0.°� •� Cedar RWer Graved Study sampflng Man February 5, 2002 Sheet 16 of 16 LEGEND Cross Sections and pebble Counts O Existing Flood Study Cross Section (King County) Existing Flood Study Cross Section (Renton) 2.286 Existing Flood Study Cross Section Selected for Survey (River Mile Denoted) 2.286 New Cross Section Added In This Study (River Mile Denoted) Alternative, Llnsurveyed Flood Study Cross • :l Sections With Good Spawning Gravel Sediment Data Existing Surface Or Subsurface Sediment Data 2.286 ® Additional Surficial Pebble Counts In This Study (River Mile Denoted) 2.286 Subsurface Sediment Sampling In This Study (River Mile Denoted) Redd Densities By River Mile Steelhead Chinook MI 0.0-4.0 0.0-4.0 4.1 -6.0 % 4.1 -6.0 6.1 - 8.0 /, 6.1 - 8.0 [] 8.1-10.0 8.1-10.0 " 10.1 > 10.1 1999/2000 Chinook Redd Locations �® Segment Breaks Segment Number o ` UIL Segment Gradient and Confinement King County Managed Flood Facilities Source: King County Department of Natural Resources, 2000. King County GIS Center, 2000. N 250 0 250 500 750 1000 Feet -- 50 0 50 100 150 Meters —� Scale: 1" = 500 feet Jones & Stokes