FORTIETH BIENNIAL REPORT 51 



Stream flow maintenance in certain areas of the high Sierra 

 Nevada has been found possible in past years through the con- 

 struction of small storage dams. Two areas, Desolation Valley 

 and Cherry Creek, have been developed through cooperation with 

 local sportsmen and the U. S. Forest Service. This work is only 

 possible where suitable sites exist, but several additional areas 

 are known where more dams could be constructed. 



An increasingly important factor affecting waters of this State 

 as habitat for fish is pollution by industries and municipalities. 

 The amount of waste that State waters are called upon to handle 

 increased greatly during the war, and will remain at a high 

 level because of the great growth in the population of the State. 

 Enforcement of the pollution laws is in the hands of the Bureau of 

 Patrol, but the Bureau of Fish Conservation supplies the tech- 

 nical service needed in connection with most pollution cases. One 

 Assistant Sanitary Engineer is assigned to the work, and his 

 time is fully occupied. It may therefore be necessary to add 

 another man to the staff next year. 



It has become more and more evident that the complexity of 

 many pollution problems makes it necessary for us to seek advice 

 and assistance from other interested agencies, particularly the 

 State Department of Public Health. Such cooperation is mutally 

 advantageous and could be facilitated by such enabling legisla- 

 tion as was proposed at the last session of the Legislature, but 

 which failed of passage. The most serious pollution is now caused 

 by food processing plans and municipal sewage, or a combination 

 of the two. Although partial removal of cannery sludge is by no 

 means a complete solution, it is recommended that the commis- 

 sion continue in effect the present regulation requiring screening 

 of cannery sewage. 



In 1945, the bureau was given the difficult task of handling the 

 screening of diversions. For a considerable period prior to that 

 administrative change, installation of new screens was confined to 

 replacement of old screens since the law provided that all new 

 installations be paid for and maintained jointly by the owner 

 and the division. The obvious difficulties of accounting, particu- 

 larly since bills for maintenance are rendered to us by the owner 

 and in most cases we would have no means of checking the labor 

 involved, were a bar to the installation of new screens. Further- 

 more, very few of the screens installed in the past had ever been 

 consistently tested to determine their efficiency in doing the job of 

 stopping small fish. It has therefore been necessary for us to 

 develop our program slowly. To start with, we set up a fish screen 

 and maintenance crew, largely with new personnel. A quonset 

 building was set up in Yreka as a shop and new equipment 

 ordered. Study was immediately given to the efficiency of various 

 types of screens, both new and old, and that work is still con- 

 tinuing. We believe that in the near future we will be ready to 

 undertake an expanded program of new installations, providing 

 changes can be made in the law. It is recommended that these 



