kO peix:ent of the potential of over 

 10,000,000 kw. has been developed (3)- 



The U. S. Bureau of Reclamation In 

 its report to the 8lst Congress, "The 

 Columbia River", 19^*7 (3)^ proposed con- 

 struction of 238 projects, large and 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"), 

 19^^, shows an viltimate developnent of the 

 Columbia River Basin that will provide a 

 total of 125,000,000 acre -feet of storage 

 on the river eind its tributaries. This 

 storage would make possible almost a com- 

 plete regulation of the river system. To 

 accomplish this, they propose the early 

 construction of 27 dams with an additional 

 131 dams, large and small, in the ultimate 

 developnent. 



Stream flow 



Average monthly stream flows and the 

 yearly mean for the period of record to 

 I9I46 are plotted on figure 5« Tabulated 

 data of water quality have the stream flow 

 recorded as of the time of sampling. 



The principal tributaries of the 

 Columbia River, their location, and their 

 mean wnmiAi flow are: (through 19^) 



Colimibla River Basin land has been 

 experiencing a constant growth Ir irriga- 

 tion for the i>a8t 100 years. Afl r 1880, 



the Increase in Irrigated land increased 

 rapidly until in 19^ > there were over four 

 million acres of land under irrigation (5), 

 about three -fourths of which were in the 

 Snake River Basin. Table 1, compiled from 

 references (3), (5)> and (6), lists the 

 acres of irrigated land tributary to vari- 

 ous segments of the Columbia River. Irri- 

 gation of potentially irrigable lEUid will 

 almost double the present irrigated area, 

 i.e.. Increase the total in the Basin to 

 over J. 3 mm ion acres. 



Figure k shows the location of exist- 

 ing and proposed irrigation areas in the 

 Columbia River Beisln. Figure 3 is a plot 

 of the growth of Irrigated land tributary 

 to VEirious segments of the Columbia River. 



Reservoirs and dama 



The construction of dams for irriga- 

 tion water impoundment and for power com- 

 menced around the turn of the century. 

 Growth of these reservoirs was rather slow 

 until after the completion of Bonneville 

 and Grand Coulee Dams in the late thirties. 

 Table A in the appendix lists the major 

 existing and proposed reservoirs in the 

 Columbia River Basin, i.e., those storing 

 in general over 50>000 acre-feet of water. 

 Data for this table were obtained frcm 

 references (3) and {k) , and by writing the 

 various private and public agencies con- 

 cerned with water i>ower and Irrigation. 

 Table 2 sunmarlzes Tcible A by listing the 

 total impoundments tributary to various 

 segments of the Columbia River by time 

 Intervals of ten years. It shows that the 

 usable storage at present is about 20 

 million acre-feet of water, and that if all 

 the proposed dams are built, the usable 

 storage will increase to about 60 million 

 acre -feet. 



Figure 6 shows the location of the 

 reseirvoirs listed in Table A in the appen- 

 dix. Figure 7 shows the growth of reser- 

 voirs in the Basin tributary to various 

 segments of the Columbia River. Figure 2 

 shows the reservoirs in relation to stream 

 elevations. 



Procedure 



The quality of water investigation 

 has proceeded in the following sequence: 



