the next best alternative. Based on work conducted by the 

 Northwest Power Planning Council, the current replacement 

 cost (excluding construction) for hydropower is approximately 

 2.5 to 3.5 cents per kilowatt hour (NWPPC 1986). Replacement 

 power provided by new thermal power plants may be three to 

 four times higher than these rates, however. Using site- 

 specific power factors that relate power generation to flow 

 and converting this flow to a volume of water, the value of 

 an acre-foot of water passing through the hydropower 

 facilities in Montana and the Columbia River Basin can be 

 estimated. Table 2-10 shows that every acre-foot of water 

 consumed in Montana will cost the region approximately $50, 

 excluding hydropower facilities in Montana. 



For the Montana hydropower facilities, the location of 

 the depletion is important. For example, if the depletion 

 occurs in the Flathead drainage below Hungry Horse Dam, the 

 lost value of an acre-foot depleted would be approximately 

 $11/AF, or $61/AF for the entire region. 



TABLE 2-10. VALUE OF ONE ACRE-FOOT OF WATER USED FOR 

 HYDROPOWER PRODUCTION 



(Based on at site and HKSUM factors from BPA) 



Source: John Tubbs, DNRC, Helena, April 1988, personal communication. 



The BOR recently completed a planning study analyzing 

 the effects of future irrigation development in the Clark 

 Fork Basin and the potential for Hungry Horse Reservoir to 

 mitigate these impacts (BOR 1988) . Analyzing the effect of 

 120,000 new acres of sprinkler irrigation development, the 

 study found that depletions would result in a loss of 261 

 million kilowatt hours (kwh) per year. This translates into 

 a financial loss of approximately $6.5 million per year, 

 assuming the current rate of 2.49 cents per kwh. The 

 estimates shown in Table 2-10 above compare favorably with 



2-17 



