Orofino Creek Passage Project Biological and Engineering Feasibility Report: Completion Report 1988.

If implemented, the Orofino Creek Passage Project will provide adult fish passage at barrier waterfalls on Orofino Creek, Idaho, and give anadromous salmonids access to upstream habitat. Anadromous fish are currently blocked at Orofino Falls, 8.3 km above the stream's confluence with the Clearwater River. This report summarizes results of a study to determine the potential for increasing natural production of summer steelhead (Salmo gairdneri) and spring chinook salmon (Oncorhynchus tschawytscha) in the Orofino Creek drainage by enhancing adult fish passage. Data on fish habitat, migration barriers, stream temperatures and fish populations in the drainage were collected during 1987 and provided a basis for estimating the potential for self-sustaining anadromous salmonid production above Orofino Falls. Between 84.7 and 103.6 km of currently inaccessible streams would be available to anadromous fish following project implementation, depending on the level of passage enhancement above Orofino Falls. These streams contain habitat of poor to good quality for anadromous salmonids. Low summer flows and high water temperatures reduce habitat quality in lower mainstem Orofino Creek. Several streams in the upper watershed have habitat that is dominated by brook trout and may be poorly utilized by steelhead or salmon. 32 refs., 20 figs., 22 tabs.