prediction of water temperature changes 

 that will be caused by the construction of 

 new reservoirs in the Columbia River Basin. 

 A previous chapter in this report discusses 

 the effect of existing reservoirs on down- 

 stream water temperatures. Table lit in the 

 chapter gives the average monthly tempera- 

 ture changes through four reservoirs. These 

 reservoirs show a maximum monthly water 

 temperatvire increase averaging 1.85° F. for 

 each million acre-feet of impoundment or 

 0.88° F. increase for each 10,000 acres of 

 average water surface area during the month 

 of August when water temperatures are at a 

 maxismm. 



Proposed reservoirs for construction 

 in the Basin are of all shapes, sizes and 

 depths. Little data are available on some 

 of the proposed reservoirs. Since the above 

 average temperatiur-e increases are for reser- 

 voirs of widely differing characteristics, 

 these figures will be used in predicting 

 futujre temperatures in the different river 

 basins if all proposed reservoirs are con- 

 structed. Table 38 lists the summation of 

 the average or usable (whichever data were 

 available) reservoir storage and the average 

 reservoir surface area above different loca- 

 tions in the Basin. Reservoir data to 1955 

 were obtained from governmental agencies, 

 private pOT/er companies and the Canada 

 Department of Northern Affairs and Natural 

 Resources. (These reservoir data are sub- 

 ject to some change as dam planning is in a 

 constant state of revision.) The table 

 gives the theoretical rise in river water 

 temperature if the increased impoundments 

 were to increase the water temperatures as 

 thejr did in the four existing reservoirs 

 used for comparison purposes. Obviously, 

 the river temperatures will not rise as 

 shOT-m in the table. The last column in the 

 table is a guess at what the actiial river 

 tem.peratureE may be if the proposed reser- 

 voirs arc constructed. This shOT^s all river 

 temperatures, excepting the Wenatchee, to 

 be in excess of 70 F. dtiring the month of 

 August with the Snake River temperatm^es 

 exceeding 75° F. (Snake River watei- tem- 

 peratures in August of 1956 occasionally 

 reached 75° F.) 



Another factor that will increase 

 river temperatures materially is increased 

 irrigation return floxi/s. If the majority 

 of the water to be stored in future reser- 

 voirs is contained in larr^e, deep inipound- 

 ments, it is possible that some river 



temperatures in August m_ay actually be 

 decreased or at least held tjo present levels. 

 There is a definite need for ncre study and 

 data on river watei' tempera tures, the influ- 

 ence thereon by dam construction and irriga- 

 tion return flows and the effect these 

 predicted temperatures ivill have on the fish 

 life in a particular stream. 



AGKNa-7LEDG?'ni;tJTS 



Supplemental data for this report 

 were kindly furnished by the U. S. Geologi- 

 cal Survey (and in particular by H. A. 

 Svjenson, District Gheriist, Portland, Oregon) j 

 U. S. Bureau of Reclamation (and in particu- 

 lar by Edwin Nasbm^g, Chief, Hydrograph;/ and 

 Drainage Branch, Epiirr.ta, Wasiilngton); U. S. 

 CoiTiE of Engineers; Chelan County Public 

 Utility District (and in particular, Scott 

 H. Bair, Hydraulic Engineer, XVenatchee, 'Jash- 

 ington) ; Canada Department of Tines and 

 Technical S\irveys; Dominion Bureau of Statis- 

 tics, Ottavja, Canada; Idaho POT^'or Company; 

 Puget Sound Power and Light Company; Canada 

 Department of Northern Affair? and Nations! 

 Resources; The Washington Water Fewer Companj^ 

 Pacific Power and Light Corripanyj City of 

 Portland, Oregon (and in particular to Fred 

 G. Kachel?ioeffer, Chemist); U. £. Public 

 Health Sei'vice; Washington Pollution Control 

 Commission; Ivan Donaldson and Fred ^Cramer, 

 Aquatic Biologists at Bonneville and McNary 

 Dams; Washington State Department of Fisher- 

 ies; U. S. VJeather Bureau; Professor Hoover 

 Mackin and Warren A. Starr for their infor- 

 mation on soil structui^e sm' geology; the 

 General Electric Company, Hanford Works; 

 Agriculture Experiment Station, University 

 of Idaho; U. S. Department of Agriculture, 

 Salinity Laboratorj', Riverside, California; 

 the U. S. Fish and Wildlife Service; Cali- 

 fornia Departm.ent of Fish and Game; and 

 California Department of Public Woi'ks. 



Data for this study were collected, 

 analyzed and summarized by the following 

 University of Washington personnel: R. 0. 

 Sylvester, Associate Professor of SanJ.tary 

 Engineering; H. P. Mittet, Associate Pro- 

 fessor of Civil Engineering; G. P. Ruggles, 

 Fisl'erles Biologist; and the following Civil 

 Engineering graduate and undergratuate 

 students : Robert Seabloom, Gerald Hansler, 

 William Peterson, James Gustafson', Robert 

 Okey, William Pj-'e, Millard Zvnvm, William 

 Ilenr;, John Underwood and Keith Dodge. The 

 sanitarj'- engineering laboratory in the 



100 



