irrigation, industrial^ and domestic uses. The stream course is en- 

 tirely on the flat V/illanette ^.''alley floor, which is farmed extensive- 

 ly, and has an average gradient of only 5.4- feet per mileo As the 

 stream meanders through the flat plain it has cut a very wide flood 

 channel; dioring low v/ater periods the stream occupies less than one- 

 third of this channel o Cut-banks occur frequently at the bends of the 

 strean, and since the banks are composed mainly of earthy sand, and 

 gravel, erosion at these points has been severe. 



The lovir suimier floi/zs over a v/ide, shallov/ stream bed api«.rently 

 iiave increased water temperatures from June through September to a 

 point where they are unfavorable for migratory fish. The survey party 

 found water temperatures ranging from 68 - 76 F., and on September 

 16 the watrfr temperature was 70,5° F., near the mouth, and 70'^ F., at 

 Jefferson, 9 miles above the mouth. Consequently^ the resident fish 

 population of the main Santiam consists mainly of rough fish such as 

 chubs, squavtfish, and suckers. Runs of spring Chinook salmon and 

 steelhead pass through the vmrm v;aters of the main Santiam to the cool- 

 er waters of the princii».l tributaries, but the main stream presents 

 definite hazards to the passage of dov/nstreaa migrants. 



Pollution, silting., and water discoloration occurs generally 

 throughout the section from the mouth to the confluence of the South 

 Santiam. The pollution condition has forced the town of Jefferson to 

 discontinue use of the Santiam for its domestic water supply. 



There are many deep resting pools and good riffles with spa-vming 

 area available for several thousand salmon in the main Santiam. How- 

 ever^ under present conditions this area is not suitable for utiliza- 

 tion by salmon and trout. 



25S-(2)c North Santiam .— (August 5-12, 1940; Parkhurst^ Bryant, 

 Frey, and Zimmer, mouth to Detroit dam site. September 2^-26, 1937; 

 Hanavan, Lobell, Baltzo, and Kolloen, remainder of stream.) Joins the 

 South Fork to form the main Santiam 11 miles above the confluence with 

 the Willamette River. The stream is 92 miles long, of which 87 miles 

 were surveyed. It originates near the summit of the Cascade slope be- 

 tween Mount Three Fingered Jack and Mount Jefferson. 



The maximum discharge recorded at Hfehama;, 28 miles above the mouth 

 and upstream from ^he principal diversions, was 62,900 c.f.s,, on 

 November 20, 1921, and the minimum \ias /iDO c.f.s., September 29 and Octo- 

 ber 13, 193A. The survey party measured a flow of 209 c.f .s., at the 

 mouth, less tJian 25 c.f.s,, at the Stayton-Kingston bridge ^between the diver- 

 sions at Stayton and their return, and 480 c.f.s., at the Mehama highway 

 bridge. The water temperature ranged from 54. ~ 61° F. On September 16 

 water temperatures were taken at a series of 10 stations from the mouth 

 to a point 68 miles upstream and ranged from 52''- 69° F. The gradient 

 in the lower 28 miles is slight (12.4-17.5 feet per mile), the stream is 



48. 



