Schult, Dennis T. 1996. Stream structures for fish habitat restoration in East Fork Potlach Creek. M.S.
247 in-stream structures placed to restore fish habitat after effects of logging and grazing were studied one year after installation to determine effects on physical channel characteristics and fish populations. Types of structures placed included log deflectors, rock weirs, rock islands, stumps, and revetments. Species of primary interest were steelhead trout (Oncorhynchus mykiss and brook trout ( Salvelinus fontinalis). Specific parameters measured included channel cross-sections immediately upstream and downstream of structures and fish populations in both treated and untreated reaches. Survival rate after one year averaged 98% over all structure types. Pools were associated with 85% of the log deflectors and rock weirs, creating a total of 137 m2 of pool area and 41 m3 of pool volume over the 5.6 km study reach. Average total salmonid density in treated reaches was 1.1/m squared compared to 0.37 m squared in untreated reaches. Recommendations regarding anchoring techniques, sizes of rocks and logs used, and selection of structure locations are also suggested.