154 



data exists at present in southwest Washington. This area is geologically 

 different enough from the rest of western Washington to warrant special 

 attention, because of the abundance of basaltic formations and marine 

 sediments. Specific needs are to monitor (1) old growth sites, including 

 those already studied by Dr. Bilby of Weyerhaeuser Co., and (2) streams in 

 managed forest over a wider range of gradient, channel confinement, and 

 channel size than present resources have allowed. Current FWS habitat 

 inventory effort is the most intensive and extensive to date in the Basin, and 

 results are expected to be useful to evaluate future timber harvest (Dave 

 Schuett-Hamee, NWIFC, pera. comm. ) . Streams of particular interest because of 

 previous or ongoing research are Thrash, Stillman, and Bingham creeks (Light, 

 pers . comm. ) . 



Porter Creek Habitat Restoration 



The Washington Department of Natural Resources is evaluating habitat 

 enhancement designed to increase coho overwintering habitat in Porter Creek. 

 Large, woody debris in the streambed is essential for habitat complexity 

 (Cederholm and Reid 1987). As in many Chehalis Basin streams, timber removal 

 from the entire stream corridor 40 to 50 years ago destroyed the pools and 

 instream winter cover, which in turn reduced coho smolt production. By 

 constructing instream winter cover, coho production should be restored. The 

 rationale for introducing cover now rather than waiting for nature to take itB 

 course is that nature may take 100 years to replace as much natural, large 

 woody debris as could be artificially placed in one or two years (Jeff 

 Cederholm, WDNR, pers. comm.). 



Experimental design consists of 1,500 meters of untouched control area, and 

 two test areas of the same size, one featuring log weirs and cabled log 

 clusters, and the other featuring debris pieces placed at the lowest possible 

 cost, with minimal attention to permanence, clustering, or high-water access 

 (Jeff Cederholm, WDNR, pers. comm. ) . Fish populations are estimated twice a 

 year and outmigrants are counted below each reach. Temperatures are also 

 monitored. Data has been collected for two years pre-project and two years 

 during construction. Two or three years of post-project monitoring are 

 planned. Results should provide good direction for habitat modification as a 

 restoration technique. 



Urbanization 



Urbanization in northern Lewis and southern Thurston Counties raises several 

 water quality questions. Monitoring should be incorporated into the design and 

 development of the new Grand Mound sewage treatment plant to avoid an increase 

 in fish kills in the area. Also, application of WDOE's 900-page manual of best 

 management practices for stormwater runoff management, developed for Puget 

 Sound, should be applied and evaluated in the Chehalis Basin. 



99 



