WRIA 31 Instream Habitat Assessment

4.0 RESULTS4.1 HABITATThe study area included the public and private lands of Rock Creek, Chapman Creek,Pine Creek, Wood Gulch, Old Lady Canyon, and Glade Creek. Data were collected in allreaches between October 29, 2008 and December 12, 2008 with the exception of GladeCreek. Data collection in Glade Creek occurred between May 28 and May 30, 2009. Allof the reaches except Glade Creek were sampled during low flow periods. Glade Creekwas sampled in May during the spring freshets; therefore, the Glade Creek data do notrepresent the low flow condition. Tribal trust lands were excluded from the datacollection effort since they are not included within the WRIA 31 planning area. Basemaps for the project areas depicting the sample locations are provided in Appendix A,Maps 1 through 8. Photos of the sample reaches are provided in Appendix B. A total of19,703 meters (57,432 feet) of stream were sampled which represented 15.7 percent ofthe total habitat in the identified reaches throughout the study area (Table 7).Average gradient in the sampled reaches ranged from 0 to 5.29 percent (Table 8). Reach3 in Wood Gulch had the steepest gradient. Other steep reaches included Reach 2 in PineCreek and the upper reaches of Rock and Squaw Creeks.Overall, 20.1 percent of the length of the sampled stream segments was dry (Table 9;Figure 6). Within the Rock Creek subbasin, the dry sections were concentrated inReaches 6, 7, and 8; continuous flow was observed in the canyon reaches upstream ofReach 8. Dry reaches were scattered throughout the other subbasins.Pools comprised 32% (Chapman Creek) to 54% (Pine Creek) of the channel unitssampled (Figure 7) and riffles covered between 15% (Glade Creek) and 57% (ChapmanCreek) of the total channel units sampled (Figure 7).Table 7. Sample reaches, total reach length, sampled reach length and percent of reachsampled.Basin Stream ReachTotalsamplelength(ft)TotalSampleLength(m)ReachLength(ft)ReachLength(m)PercentSampledChapmanCreekCHAPMANCREEK 1 1,109 338 1,312 400 84.5%ChapmanCreekCHAPMANCREEK 2 3,174 967 12,139 3,700 26.1%ChapmanCreekCHAPMANCREEK 3 2,069 631 6,234 1,900 33.2%ChapmanCreek Total 5,906 1,800 19,685 6,000 30.0%Pine Creek PINE CREEK 1 2,417 737 21,325 6,500 11.3%Pine Creek PINE CREEK 2 1,275 389 12,139 3,700 10.5%Pine Creek PINE CREEK 3 1,847 563 10,171 3,100 18.2%Pine Creek PINE CREEK 4 1,375 419 14,436 4,400 9.5%WRIA 31 Instream Habitat Assessment 19 Watershed Professionals Network