the upstream end of the future Rocky Reach 

 reservoir. Station 22 on the upper Yakima 

 River was sampled, since it was on the 

 travel route of the Scunpling party and 

 would thus give valuable information on a 

 regulated stream with a minimum of cost 

 cind effort. 



Plates I-V (pages 9-13) show these 

 sampling stations and the initial construc- 

 tion work on the Rocky Reach and Priest 

 Rapids Dams. 



RIVER BASIN CHARACTERISTICS 



Characteristics of the principal 

 streams in the study area are given in 

 table 3. Nason Creek has not been gaged 

 sufficiently to permit an analysis of its 

 flow characteristics. All streams have a 

 very wide fluctuation in flow during a 

 normal water year. Table 4 (page 16) gives 

 the mean monthly discharge of the streams 

 in the vicinity of the sampling stations 

 during the period of the study. In a given 

 month, the average monthly flow from year 

 to year may vary by as much as 670 percent. 

 These monthly flow variations and the yearly 

 flow variations have a marked effect on the 

 water quality and on the biota. 



The yearly average flows during the 

 Study period were generally greater than 

 the average flows of records, as shown in 

 table 4. These higher flows may reduce the 

 biota of the stream through scour and 

 through a reduction in dissolved mineral 

 matter concentrations. 



Stream flow in 1939 and 1940 was 

 considerably less than in 1954-57. The 

 greatest stream discharge during the study 

 period was in the 1956 calendar year. 



Columbia River Basin 



The principal river basin in the 

 Pacific Northwest is the Columbia River 

 Basin. This river system likewise has the 

 greatest multipurpose water uses existing 

 and proposed. It has supported very large 

 runs of anadromous fishes, for whose con- 

 tinuation huge sums of money have been 

 spent. This water quality study has con- 

 fined itself within a small portion of the 

 Columbia River Basin as shown in figure 1. 

 There is a total of some 259,000 square 

 miles in the drainage basin, of which 



39,700 are in Canada. It includes most of 

 the States of Washington, Idaho, and Ore- 

 gon, the western part of Montana, and 

 smaller areas in Nevada, Wyoming, and Utah, 

 comprising about 7 percent of the nation's 

 area. 



The Columbia River has its headwaters 

 in Columbia Lake, British Columbia, about 

 70 miles north of the international border 

 at an elevation of 2,650 feet. After flow- 

 ing 465 miles through Canada in a circui- 

 tous manner, the river enters the United 

 States near the northeast corner of Wash- 

 ington. It flows through Washington in 

 a series of big bends and becomes the border 

 between Washington and Oregon as it flows 

 westward to the Pacific Ocean. Between 

 headwaters and the ocean, the river is some 

 1,200 miles long. Its annual average flow 

 is around 160,000,000 acre-feet of water 

 (or 220,000 cubic feet per second) that is 

 discharged into the Pacific Ocean. The 

 headwaters of the Columbia and its princi- 

 pal tributaries are in the mountains where 

 precipitation is fairly high. Mountain 

 snow packs produce ground storage plus 

 seasonal peak flows in late spring. 



The central portion of the Columbia, 

 like its principal tributary, the Snake, 

 lies in an arid region where irrigation is 

 necessary for diversified farming. About 

 4,650,000 acres are now (1957) under irri- 

 gation (^) (7) , two-thirds of which are 

 in Southern Idaho. Ultimate development 

 calls for a total of about 7,500,000 acres 

 to be irrigated (8). 



Because of its rapid fall from head- 

 waters to the ocean, the Columbia and its 

 tributaries offer many sites for hydro- 

 electric power development. Despite the 

 fact that there are now nearly 200 hydro- 

 electric power developments in the Basin, 

 only about 40 percent of the potential of 

 over 10,000,000 kw. had been developed (8) 

 as of 1947. (This figure has now increased 

 to over 50 percent). 



The U. S. Bureau of Reclamation in 

 its report to the 81st Congress, "The 

 Columbia River," 1947 (8), proposed con- 

 struction of 238 projects, large jind small, 

 for irrigation, power, and flood control. 

 The U. S. Corps of Engineers, North Pacific 

 Division, in its "Review Report on Columbia 

 River and Tributaries" ("308 Report"), 

 1948, (3), shows an ultimate development of 



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