Steelhead Malntenanoe 



Maintenanoe of the steelhead trout population would not 

 present the serious problems inherent in the perpetuation of salmon 

 if a dam is constmioted at the Lewiston site. These fish are believed 

 to spawn voluntarily in the lower reaches of tjie river during low 

 water years and their nests are made during the spring run-off period* 

 Muoh steelhead spawning takes plaoe in tributaries in the main river 

 below Lewis ton which are all carrying ample water to produce adequate 

 available gravel during the steelhead spawning period* 



TO accommodate steelhead spawning in the river, a flow of 150 o.f .0. 

 would be required during the steelhead spawning period. This flow is 

 included in all flow schedules for salmon spawning that are suggested in 

 this report. The inflow from tributaries in the upper portion of the 

 spawning area below the Lewis ton dam (T&ble 23) will make additional 

 spawning area avail&ble in the main river for steelhead blocked by the 

 dam. Tributary inflow peaks during the steelhead spawning season and 

 should be fairly reliable from year to year. These tributaries are, at 

 present, under-populated with spawning steelhead. If mining silt can be 

 excluded from tributaries during the spawning and incubation period 

 (February 15 through June 15), they would be better suited to accommodate 

 part of the steelhead held back by the Lewis ton dam. Uajor steelhead 

 spawning tributaries below Lewiston dam site are Rush Creek, Grass Valley 

 Creek, Indian Creek, Redding Creek, Browns Creek, Canyon Creek, and the 

 North Fork of the Trinity, including its East Fork. 



Browns Creek dam would present a major problem in connection 

 with steelhead spawning. Only two of the major spawning tributaries 

 are below this dam, thvts an unknown number of these fish would have to 

 be diverted into the South Fork, or removed into a hatchery, or both. 

 Neither possibility would seem feasible when it is considered that 

 streams and hatchery facilities would have to be developed to a maximum 

 for the salmon alone, and a project including steelhead salvage would 

 involve operations of unprecedented proportions. 



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