WRIA 31 Instream Habitat Assessment

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The sampled stream segments were assumed to be representative of the entire streamreach. The information collected was used to support the estimation of the quantity andquality of spawning and rearing habitat throughout the basin. Data analysis relative tostream temperature relied on stream temperature data collected by the Central KlickitatConservation District and reported by Aspect (2005) and temperature data gathered bythe Washington Department of Ecology at the flow gage(https://fortress.wa.gov/ecy/wrx/wrx/flows/station.asp?sta=31B070).3.5 SEDIMENT SOURCE MODELINGSediment input was estimated based on observations made during a 1-day sitereconnaissance, viewing orthophotographs to help identify land uses and sedimentsources, and GIS modeling of sediment inputs (Table 2).Table 2. Summary of methods used to estimate sediment inputs.Sediment SourceMethodSoil creep/streambank erosionAgricultural landRoad surfaceerosionA combined estimate was based on SEDMODL2 calculationsThe WEPP model was used to estimate erosion and delivery ratesfrom representative field/buffer/slope combinations. These sedimentinput rates were extrapolated to croplands within 1,000 feet of streams.Erosion from grazing of streamside vegetation was evaluated basedon percent of stream length observed to be damaged by grazingduring the stream inventory, extrapolated to rest of stream areasutilized for grazing.Observations of road conditions/lengths/delivery were made during a1-day site visit. Erosion/delivery estimates were based on SEDMODL2calculations on all roads in GIS database3.5.1 Data SourcesThe following GIS coverages and data were used in the analysis:• Topography – USGS 10 meter Digital Elevation Model• Streams – Washington State Department of Natural Resources Watercourse(WC) Hydrography (WDNR Jan. 2009)• Roads – State Transportation coverage (WDNR Jan. 2009)• Geology – WDNR 1:100,000 scale geology (WDNR 2000)• Soils – NRCS soils, combined WA DNR coverage for Klickitat county andSSURGO for Benton and Yakima counties. Acquired from Aspect Consulting• Land Use – US National Land Cover Data (NLCD) from1992 Landsat data.Acquired WRIA31 subset of data from Aspect Consulting (USGS 1992)• Data from the crop analysis completed in 2004 (IRZ 2004) and a crop databaseprovided by the Washington Department of Agriculture (2009) which providesinformation on crops and irrigation in the project areaWRIA 31 Instream Habitat Assessment 13 Watershed Professionals Network
• Existing traffic count data for portions of gravel-surfaced roads in KlickitatCounty obtained from the County (personal communication, Seth Scarola, ProjectEngineer, Klickitat County Pubic Works, June 1, 2009)In addition, observations on the types of land uses/sediment sources in the subbasins andaverage road conditions across the subbasins were made during a site visit on May 14,2009. The objective of the reconnaissance-level site visit was to observe existingconditions and sediment-producing activities in the subbasins. Observations ofcroplands, road drainage connectivity, unpaved road conditions, potential sedimentdelivery pathways, and presence/absence of defined channels at road crossings weremade. Approximately 200 miles of road within the four subbasins were driven.Based on field observations, type N and U (non-fish bearing) streams in areas underlainby loess and fine-grained flood deposits (Ql and Qfs geologic units) and were notincluded as streams in the analysis of sediment delivery in the Glade Creek subbasin.During the field checking, there were swales, but very few actual channels were found inlocations that were mapped as type N or U on Ql and Qfs geologic units. It is possiblethat mapped streams in parts of other subbasins, particularly lower Rock Creek, are notactually streams on the ground, but we did not have adequate field data to verify streampresence/absence in other subbasins. Since sediment delivery estimates were based onmapped streams, a higher number of mapped streams will result in an overestimate ofsediment delivery to streams.3.5.2 Soil Creep and Stream Bank ErosionSoil creep and stream bank erosion are natural processes that occur along all streams andprovide a background level of sediment input to streams. Soil creep is the slowdownward motion of the soil column due to gravity and provides sediment to streambanks where it enters the stream. In some locations in larger, alluvial sections of streams,the flow has enough energy to erode the stream banks, providing sediment from thismechanism. In general, soil creep is considered the input mechanism in smallerheadwater channels, while stream bank erosion is often the input mechanism in largerchannels. Based on observations by the stream inventory crew, stream bank erosion doesnot appear to be widespread in WRIA31. For this reason, the estimate of soil creep fromthe SEDMODL2 application was used to estimate sediment input from both thesesources. A soil depth of 60 inches was used based on depths reported for soils in thewatershed by the NRCS (http://websoilsurvey.nrcs.usda.gov/app/). The lowest creeprates in SEDMODL2 (0.03/0.07 mm/yr for slopes greater and less than 30 percent,respectively) were used due to the low rainfall in the area.3.5.3 Agricultural LandsAn assessment of erosion and delivery from agricultural lands was made using the WEPPmodel (http://www.ars.usda.gov/Research/docs.htm?docid=10621) and existing GIScoverages showing land use.3.5.4 Cultivated LandWRIA 31 Instream Habitat Assessment 14 Watershed Professionals Network
Page 1: WRIA 31 InstreamHabitat AssessmentG
Page 5 and 6: Table of ContentsAbstract..........
Page 7 and 8: List of FiguresFigure 1. Study area
Page 9 and 10: We wish to thank the Nature Conserv
Page 11 and 12: Figure 1. Study areaWRIA 31 Instrea
Page 13 and 14: around 24 inches along the western
Page 15 and 16: Figure 3. Daily maximum water tempe
Page 17 and 18: Figure 4. Major streams in WRIA 31.
Page 19 and 20: Table 1. Data collected in the fiel
Page 21: Hydromodifications were noted withi
Page 25 and 26: Cultivated small grains; and Cultiv
Page 27 and 28: 3.5.6 Road Surface ErosionSEDMODL2
Page 29 and 30: Totalsamplelength(ft)TotalSampleLen
Page 31 and 32: Table 9. Number and type of channel
Page 33 and 34: 60.0%Percent of EachChannel Unit Ty
Page 35 and 36: Table 10. Pool Volume in each reach
Page 37 and 38: Table 12. Spawning area in each rea
Page 39 and 40: Chapman CreekAverage PercentComposi
Page 41 and 42: spawning habitats. Spawning areas a
Page 43 and 44: Chapman Creek30Number2010075%% Embe
Page 45 and 46: Basin Stream Reach CanopyCover (%)W
Page 47 and 48: 4.2 FISH SURVEYS4.2.1 Snorkel Surve
Page 49 and 50: 4.2.2 Spawning SurveysSpawning surv
Page 51 and 52: small depression 0.5 foot deep is p
Page 53 and 54: the heavy rainstorms which occurred
Page 55 and 56: Figure 16. 1992 Landsat land cover
Page 57 and 58: locations, the livestock have free
Page 59 and 60: Figure 18. Stream flow, water tempe
Page 61 and 62: mortality reported at various sedim
Page 63 and 64: some cases, the sparse condition is
Page 65 and 66: was based on a one-day site visit a
Page 67 and 68: Aspect Consulting, LLC 2005. Rock C
Page 69 and 70: Reiser, D.W., and R.G. White. 1988.

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