36 



FISH AND GAME COMMISSION 



salmon. The ascent has been made much easier for steelhead and they 

 have proceeded on upstream with no apparent difficulty. 



The sanitary district operating in the vicinity of the Woodbridge 

 Irrigation District dam desired to change operating conditions of this 

 dam in its program of mosquito control making considerable altera- 

 tions in the fishway necessary. The bureau furnished new plans and 

 money was provided by local contributions, the irrigation district doing 

 the work and also absorbing some of the cost. The fishway as recon- 

 structed appears to be satisfactory. 



On the North Fork of the Feather River is a dam which was 

 equipped with a fishway which had not functioned for a number of 

 years due to raising of the water level by the use of flashboards on 

 the dam without any consideration of the then installed fishway. Plans 

 were given to the company owning this dam for the improvement of 

 the fishway and a substantial structure of concrete and lumber was 

 installed. The water level in this reservoir fluctuates greatly over 

 short periods of time and to meet that condition the five upper pools 

 were designed to operate automatically by mechanical means. At the 

 present time, new equipment is being installed which it is believed 

 will make this fishway fully operative at all times. This will make 

 available many miles of desirable spawning area for the migrating 

 trout and salmon. 



Fig. 8. Fishway over Folsom Dam on American River. Maximum difference in 

 elevation, 45 feet. Lowest four pools (at left) completely submerged. 

 Four adjustable ports at upper section. 



At Merced Falls on the Merced River, a new fishway was con- 

 structed when the dam at that point was rebuilt and raised. The fish- 

 way is of reinforced concrete construction and should require nothing 

 further if conditions do not change. 



A company constructed a dam on the South Fork of the Eel River 

 in Humboldt County and did not provide for a fish ladder although 

 plans had been furnished in ample time by the bureau for such an 

 installation. As a result the first run of king salmon ascending beyond 



