Biological and Physical Inventory of Clear Creek, Orofino Creek, and the Potlatch River, Tributary Streams of the Clearwater River, Idaho, 1984 Technical Report.

Clear Creek, Orofino Creek, and Potlatch Creek, three of the largest tributaries of the lower Clearwater River Basin, were inventoried during 1984. The purpose of the inventory was to identify where anadromous salmonid production occurs and to recommend enhancement alternatives to increase anadromous salmonid habitat in these streams. Anadromous and fluvial salmonids were found in all three drainages. The lower reach of Clear Creek supported a low population of rainbow-steelhead, while the middle reach supported a much greater population of rainbow-steelhead. Substantial populations of cutthroat trout were also found in the headwaters of Clear Creek. Rainbow-steelhead and brook trout were found throughout Orofino Creek. A predominant population of brook trout was found in the headwaters while a predominant population of rainbow-steelhead was found in the mainstem and lower tributaries of Orofino Creek. Rainbow-steelhead and brook trout were also found in the Potlatch River. Generally, the greatest anadromous salmonid populations in the Potlatch River were found within the middle reach of this system. Several problems were identified which would limit anadromous salmonid production within each drainage. Problems affecting Clear Creek were extreme flows, high summer water temperature, lack of riparian habitat, and high sediment load. Gradient barriers prevented anadromous salmonid passage into Orofino Creek and they are the main deterrent to salmonid production in this system. Potlatch River has extreme flows, high summer water temperature, a lack of riparian habitat and high sediment loads. Providing passage over Orofino Falls is recommended and should be considered a priority for improving salmonid production in the lower Clearwater River Basin. Augmenting flows in the Potlatch River is also recommended as an enhancement measure for increasing salmonid production in the lower Clearwater River Basin. 18 refs., 5 figs., 85 tabs