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FINAL PROGRESS REPORT PROJECT: CHINOOK RIVER DIVERSION

Funder: Lower Columbia River Estuary Partnership Fundee: Columbia River Estuary Study Taskforce

April Silva Wetland Monitoring Specialist

Columbia River Estuary Study Taskforce 750 Commercial St Rm 205

Astoria, OR 97103 Phone: (503) 325-0435 Fax: (503) 325-0459

Email: [email protected]

Chinook River Diversion Habitat Reconnection Project

This report documents activities associated with Phase I & II of the Chinook River Diversion Project. The primary project goal is to replace an outdated hatchery diversion/fish ladder effectively reconnecting critical spawning and rearing habitat for salmonids. The diversion dam/fish ladder located at RKM 3.1 on the Chinook River serves as the only water supply for the Sea Resources Hatchery & Education Center. As described in the WDFW Fishway Assessment Report the diversion/fish ladder is a 30+-year-old pool and weir fishway consisting of 6 weirs constructed from concrete weirs and wooden boards. The removal and placement of these large boards is necessary to maintain passage under varying flowconditions. Without continual management the structure acts as a passage barrier for both ad

juvenile salmonids. Boswell Consultants lists the diversion in their 2006 habitat survey as a partial low flow barrier for juvenile salmonids. The diversion is nearly a complete barriechum, preventing 95% to 99% of adult Chum from migrating upriver (Warren 2

ult and

r to 007).

Phase I of the project includes preliminary survey and modeling of the project site and selected hatchery structures, preparation for riparian plantings, as well as pre-project monitoring. Phase II of the project includes riparian enhancement, construction, and post project monitoring.

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PHASE I TASK 1: Topographic Survey: Status- Complete Initial surveying and topographic mapping was completed in early September by HLB/OTAK. Surveying was conducted in two areas, at the project site and at the Sea Resources Hatchery. Horizontal control for the project is North America Datum of 1983 (NAD 83) with Washington South Zone. Vertical control for the project is North America Vertical Datum of 1983 (NAVD 83). As stated in their scope of work HLB/OTAK completed the following:

1. Horizontal and vertical controls were established; control monuments were surveyed to facilitate later project surveys.

2. Channel cross-sections above and below the structure 3. Coordinates of previously placed channel cross-section markers 4. Top elevation and coordinates of the existing fish ladder concrete walls at each

corner/step 5. Top elevation and coordinates of the four corners of the three metal walkways on the

existing structure 6. Coordinates of the partially submerged valve situated just downstream of the upper most

weir 7. Top of green water supply pipe on the left bank side if the channel nearest to the hatchery 8. Coordinates of the white PVC piped feeding each hatchery trough 9. Topographic map of the project site

Deliverables are attached to the hard copy of this report as Addendum A. TASK 2: Hydraulic Modeling: Status- Complete Hydraulic modeling was conducted in order to develop criteria for selecting a design alternative that address limiting factors for salmon passage. A technical memo is attached in Addendum B.

1. R2 estimated the 100 yr flood magnitude for stability and structural performance design, and appropriate upper and lower fish passage flows for adult and juvenile salmon

2. R2 constructed a HEC-RAS model of the existing reach for use in predicting depths and velocities, and a model of the selected alternative for use during the design

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PHASE II Habitat Reconnection- Status: Incomplete Road improvements are scheduled to begin in spring of 2009, with replacement and instillation of the new structure to follow during the in-stream work window. Construction is scheduled to be complete by September of 2009. Currently phase II is well within the estimated timeline for completion. Riparian Enhancement- Status: Incomplete

Riparian plantings address the only limiting habitat factors addressed in the 2006 habitat survey (Boswell Con). They will be done with the objective of creating shade and the potential for future LWD recruitment. A variety of coniferous tress and native shrubs have been selected and are ordered to arrive in December of 2008. Species selected include Sitka Spruce (Picea sitchensis), Western Red Cedar (Thuja plicata), Big Leaf Maple (Acer macrophyllum), Pacific Ninebark (Physocarpus capitatus),

Snowberry (Symphoricarpos albus), Black Twinberry (Lonicera involucrate), and Indian Plu(Oemlaria cerasiformis). Riparian enhancement is scheduled to begin January 2009 to March2009. Planting efforts will be closely coordinated with Sea Resources with an emp

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hasis of ommunity involvement and volunteers.

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Addendum B

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15250 NE 95th StreetRedmond, WA 98052-2518

Phone: (425) 556-1288Fax: (425) 556-1290

E-mail: [email protected]

R2 Resource Consultants, Inc.

Technical Memorandum No. 1 Date: September 11, 2008 Project Number: 1702.01

To: April Silva, CREST

From: Paul DeVries Ph.D., P.E.

Subject: Surveying and Hydraulic Modeling Report, Chinook River Diversion Project 1. BACKGROUND The primary goal of the Chinook River Diversion Project is to improve upstream passage at the site of a diversion that provides water to the Sea Resources hatchery, located at approximately RKm 4 on the Chinook River. The existing fishway at the diversion is considered to be a low flow passage barrier (Boswell Consultants 2006) and chum salmon (Oncorhynchus keta) do not readily pass upstream due to the design. In order that chum salmon pass upstream and make use of available habitat there, CREST desires that a new passage facility be designed and constructed. In addition, the diversion has trapped bedload behind it. The aggraded nature of the channel has facilitated the initiation of high flow routing around the diversion structure, leading to erosion and increased potential for avulsion. CREST correspondingly desires that the fish passage solution also consider avulsion potential if necessary. At the same time, the fish passage and avulsion solutions need to be consistent with providing a reliable water supply to the Sea Resources Hatchery that relies on the diversion to maintain sufficient head. If necessary, the hatchery water supply intake system may need to be modified while meeting NMFS and WDFW screening criteria. R2 Resource Consultants, Inc. (R2) was contracted by the Columbia River Estuary Study Taskforce (CREST) to provide engineering design services needed for implementing the project.

This technical memorandum summarizes the analyses performed by R2 as part of developing hydraulic models for use in the design process, using survey data collected by HLB-Otak under separate contract to CREST, supplemented by survey data collected by R2.

2. SURVEY DATA R2 received a draft contour map in AutoCAD and the associated points file containing coordinates and elevations from HLB-Otak. The points data included surveyed cross-sections, two of which coincided with cross-sections surveyed previously by P. DeVries with the assistance of April Silva (CREST). A comparison of the two sets of cross-section data indicated that the HLB-Otak data were correct and could be used in the formulation of HEC-RAS models. The contour map generated by HLB-Otak is depicted in Figure 1.


Figure 1. Contour map of channel, with fishway and hatchery water supply elevations surveyed by HLB-Otak.

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3. HEC-RAS MODEL DEVELOPMENT R2 constructed a HEC-RAS model of the existing reach for use in predicting depths and velocities, and a model of the selected alternative for use during the design (Figure 2). The model was adapted to represent hydraulic conditions associated with alternative designs, including a concrete pool and chute (Alt 1), rock weir and pool (Alt 2), and roughened channel configurations (Alt 3). Given the local reach gradient upstream and downstream (around 0.5%-0.8% according to the Boswell Consultants 2006 report) and head drop across the diversion, it appears that these alternatives could all feasibly provide passage for adult chum salmon and juveniles of all native salmonid species in the basin over a range of flows. The modeling is being used to assess alternative feasibility and as input to the final design, and for assessing potential effects on bank over-topping. Modeling considerations include allowing for passage over the range of flows required by WDFW and NMFS fish passage criteria.

Manning’s n roughness coefficients were estimated to be 0.05 in the main channel and between 0.07-0.08 on the banks and floodplain based on professional experience. The channel below the project is relatively prismatic with gradually varying slope, thus it was reasonable to approximate downstream model boundary conditions by assuming normal depth conditions.

ChinookRiver Legend

WS Juv LFP

WS Adt LFP

WS Juv HFP

WS Adt HFP

WS Q100 (290)

Ground

Bank Sta

Inef f

Figure 2. HEC-RAS model of Chinook River Diversion Project reach, existing conditions.

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4. FLOW DATA FOR HYDRAULIC MODELING AND DESIGN R2 estimated the 100 yr flood magnitude for stability and structural performance design, and appropriate upper and lower fish passage flows for adult and juvenile salmon. It was not possible to discern a characteristic bankfull flow level in the field as part of modeling and assessing sediment transport-related design issues.

100-yr Flood: The 100 yr flood was estimated as 290 cfs, based on regional regressions for Washington in Sumioka et al. (1997) and for Oregon in Jenning’s et al. (1994). The regression equations were used to estimate peak flow magnitudes for the 2-, 10-, 25-, 50-, and 100-year events. Both regressions required drainage area as input. Amy Ammer used CREST GIS data and determined the drainage area at the bridge at the hatchery to be approximately 3.2 mi2. There are no major tributaries between the diversion and the bridge, thus using the bridge drainage area adds a factor of safety in the flood flow estimates. The Washington regression also required mean annual precipitation, which based on the same data used to generate the regressions for nearby gaging stations, was estimated as 91 in/yr. The Oregon regression also required estimates of the 2 yr 24 hour precipitation, which was estimated using regression input data of Harris et al. 1977 as about 4.5 in, and the percent of basin area comprised mean annual precipitation, which was assumed to be 1% to allow for minor flood attenuation effects of beaver ponds located upstream.

The Washington regression gave an estimated average peak flow magnitude for the 100-year event (Q100) of 650 cfs, with +/- 1 standard error (SE) ranging between 290 cfs and 1000 cfs (all flows are rounded here to 2 significant figures). The Oregon regression gave an estimated average peak flow magnitude for the 100-year event (Q100) of 480 cfs. The mean regression estimates were greater than an estimate of 210 cfs for the 100-year storm at a downstream location (drainage area = 3.6 mi2), derived by Khangaonkar et al. (2006) using the HEC-HMS hydrologic runoff modeling software. The HEC-HMS-derived estimate suggests that the ‘true’ Chinook River 100-yr flood magnitude is likely to fall nearer the lower confidence limit of the regression predictions, and thus the -1 SE estimate = 290 cfs from the Washington regression was selected as the 100-yr flood estimate for hydraulic modeling and design.

Inspection of the existing conditions HEC-RAS model indicated that the 290 cfs level overtopped the stream banks upstream of the diversion by several feet, whereas downstream within the more confined channel, this level approximated the top of bank (Figure 3). Thus, the larger flow estimates would be expected to spread out over the floodplain and not be associated with significantly greater erosive power than the 290 cfs level, indicating that this is a reasonable upper target flow for hydraulic modeling and design.

Fish Passage Flows: WDFW regression equations (WDFW 2003) were used to estimate the range of high flows up to which fish passage should be provided. The mean January upper limit fish passage flow regression estimate was 81 cfs, with a +/- 1-SE range = 50-112 cfs. The mean May upper limit fish passage flow regression estimate was 23 cfs, with a 1-SE range = 14-32 cfs. Given that the regression followed the same approach as that used by Sumioka et al. (1977), it is likely that the mean predictions are over-estimates similar to the 100-yr flood. Thus, the design upper fish passage flow was selected to be the -1 SE estimate = 50 cfs.

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-10 0 10 20 30 40 5021

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25

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ChinookRiver RS = 315 Station 315 = Just D/S of R2 Tr3

Station (f t)

Elevation (ft)

Legend

WS Q100 (290)

WS Adt HFP

WS Juv HFP

WS Adt LFP

WS Juv LFP

Ground

Inef f

Bank Sta

.07 .05 .08

0 5 10 15 20 2515

16

17

18

19

20

ChinookRiver RS = 29 Station 29

Station (f t)

Elevation (ft)

Legend

WS Q100 (290)

WS Adt HFP

WS Juv HFP

WS Adt LFP

WS Juv LFP

Ground

Bank Sta

.08 .05 .08

Figure 3. Representative cross-section profiles above (top) and below (bottom) the Chinook River diversion. The WDFW regression estimates are based on an assessment of the 10% exceedance flow (WDFW 2003). Independent estimates were derived of the 5% and 10% exceedance flow using regressions for Oregon developed by Risley et al. (2008), which included gaging station data in the vicinity of the

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Chinook River in SW Washington. The mean regression predictions correspondingly were 74 cfs and 50 cfs, respectively. Assuming, based on the conclusion that regional flow regressions tend to over-predict flow statistics for the Chinook River Diversion Project site, the selected target flows of 50 cfs for adults and 14 cfs for juveniles appear to be reasonable approximations of the upper fish passage design limits. WDFW (2003) recommends the 2-yr 7-day low flow as a suitable low flow fish passage criterion. The regression relation developed by Risley et al. (2008) predicts this to be 0.6 cfs. Alternatively, NMFS (2008) indicates the 95% exceedance flow during the season of passage, or the lowest flow at which upstream migrants are expected to be migrating. The regression relations developed by Risley et al. (2008) indicates the 95% exceedance flow to be 1.4 cfs on an annual basis, or between 1.8 cfs and 7.9 cfs from October through December (monthly basis). Using the lower value of 1.4 cfs would provide a level of conservativeness in the design. Assuming a limiting passage depth criterion of 0.8 ft (WDFW 2003) for adult trout and salmon, the HEC-RAS model indicates that existing downstream cross-sections are depth-limited at flows above 1.4 cfs (Figure 4). Reasonable estimates of the low flow passage design targets therefore appear to be 1.4 cfs for adults, and 0.6 cfs for juveniles. Summary: The following target hydraulic modeling and design criteria for acceptable project stability and passage conditions are concluded from this assessment:

• 100-yr Flood Flow = 290 cfs • Upper Passage Flow (adult) = 50 cfs • Upper Passage Flow (juvenile) = 14 cfs • Lower Passage Flow (adult) = 1.4 cfs • Lower Passage Flow (juvenile) = 0.6 cfs

A design that affords passage outside of these target ranges would be considered to provide for excellent passage conditions, if feasible. These are the flows that are modeled using HEC-RAS for the Chinook River Diversion Project.

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4 6 8 10 12 14 16 18 2015

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ChinookRiver RS = 60 Station 60

Station (f t)

Elevation (ft)

Legend

WS Q100 (290)

WS Adt HFP

WS Juv HFP

WS Adt LFP

WS Juv LFP

Ground

Bank Sta

.08 .05 .08

-5 0 5 10 15 20 25 30 3516

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18

19

20

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ChinookRiver RS = 156 Station 156 = R2 Tr2

Station (f t)

Elevation (ft)

Legend

WS Q100 (290)

WS Adt HFP

WS Juv HFP

WS Adt LFP

WS Juv LFP

Ground

Bank Sta

.08 .05 .08

Figure 4. Cross-section profiles of low flow limiting passage transects below the Chinook River Diversion. Key to flows: Adt HFP = 50 cfs; Juv HFP = 14 cfs; Adt LFP = 1.4 cfs; Juv LFP = 0.6 cfs.

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5. REFERENCES Harris, D.D., L.L. Hubbard,, and L.E. Hubbard. 1979. Magnitude and frequency of floods in Western

Oregon. U.S. Geological Survey Open File Report 79-553. Portland Oregon. Jennings, M.E., W.O. Thomas, Jr., and H.C. Riggs. 1994. Nationwide summary of U.S. Geological

Survey regional regression equations for estimating magnitude and frequency of floods for ungaged sites, 1993. U.S. Geological Survey Water-Resources Investigations Report 94-4002. Reston Virginia.

Khangaonkar T., S. Breithaupt & F. Kristanovich. 2006. Restoration of hydrodynamic and hydrologic

processes in the Chinook River Estuary, Washington – Feasibility assessment. Pacific Northwest National Laboratory, Battelle Seattle Research Center, Seattle, WA.

National Marine Fisheries Service (NMFS). 2008. Anadromous salmonid passage facility design.

Northwest Region, Portland OR.

Risley, J., A. Stonewall, and T. Haluska. 2008. Estimating flow-duration and low-flow frequency statistics for unregulated streams in Oregon. U.S. Geological Survey Scientific Investigations Report 2008-5126. Portland Oregon.

Sumioka, S.S., D.L. Kresch, and K.D. Kasnick. 1997. Magnitude and Frequency of Floods in

Washington. USGS Water-Resources Investigations Report 97-4277.

Washington Department of Fish and Wildlife (WDFW). 2000. Fishway guidelines for Washington State. Olympia WA.

Washington Department of Fish and Wildlife (WDFW). 2003. Design of road culverts for fish passage.

Olympia WA.

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