f 



have been made on Ruah Creek and Parts of the South Fork at lower than 

 optimtim flows. With this information, the approximate nesting capacities 

 of the tributaries at their optimvun flows have been estimated. Using 

 the nests per cubic foot per second per mile factors, established for 

 portions of the Trinity River at the 100 cubic feet per second flow, 

 nesting capacities were computed for comparable portions of the tribu- 

 taries at their optimum flows (Table 24). Normal spawning flows for 

 these streams were set up by evaluating statements made by people living 

 along the streams and comparing this infonmation with the few flow 

 records that are available* 



Improvement of these streams could probably make an additional 

 3,565 nests available for 9,376 spawning salmon. In order to make these 

 nests available, additional water development on each stream is necessary* 

 Rather large storage dams should be built in the upper portions of each 

 stream drainage to provide a constant and adequate minimum flow during 

 the entire year. Greater flows would be necessary when spawning occurs. 

 It would be desirable to remove several obstructions which are barriers 

 to fish migration during low water periods. Natural barriers obstruct 

 fish movements into Hay Fork Valley. Artifical dams and diversions 

 block from access miles of spawning area in Browns and Rush Creeks when 

 water flows are low. 



Two methods of developing salmon runs in these streams, after 

 improvement, are possibles (1) Salmon could be trapped at Lewiston or 

 at other locations above the mouth of South Fork and hauled to the 

 streams J (2) small runs now entering the streams or present in the main 

 Ti*inity off their mouths could be left to take over the new spawning 

 areas and develop natural runs to offset losses of salmon blocked by 

 the Lewiston dam. Experience would dictate the latter course of action, 

 although it may be very slow and gradual in developing. Transferring 

 adult salmon is a costly process, not only in money, but also in fish. 

 It is generally better to encourage a native seed stock to increase in 

 abundance than to introduce a foreign race which may or may not adapt 

 to the new situation. This attitude is especially applicable to the 

 South Fork of Trinity River and its major tributary. Hay Fork. Some 

 main stream salmon probably could be diverted into South Fork, Browns 

 Creek and Rush Creek by constructing barriers on the main Trinity 

 immediately above their respective mouths, but such construction would 

 be costly and might result in serious disruption of the normal habits 

 of the entire anadromous fish population. There are no means available 

 whereby fish headed for the area above Lewiston can be segregated from 

 those using the river below that point. 



Fterhaps the most serious obstacle in any plan to transfer salmon 

 from one place to another in the Trinity River drainage is the almost 

 utter lack of good roads. Tank trucks suitable for hauling adult salmon 

 are very heavy and would operate in months when roads are wet and slippery. 

 It is doubtful that any transfer program could be successful without major 

 road construction and bridge strengthening projects preceding the actual 

 truck operation. 



67 



