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III-10 I I I I I I I I I I I I I I I I I I I however, at some sites where the thermal effects would not be objectionable. Dry cooling towers were selected at sites where cooling water supplies are critically short and the value of generation at the site may justify the large expense. Dry cooling towers are assumed to require negligible volumes of water. In the case of plants using cooling water from ground water sources, it is assumed that return flows would be returned to either fresh or saline water bodies or, in some desert areas, to be placed on the ground to evaporate. Steam used for generation purposes at geothermal plants is assumed to be returned to the ground after condensation to avoid subsidence, Cool ing water used in the process is included in estimates of water use, Hydroelectric Plant Water Use The average annual generation in each ASA during 1975, 1985 and 2000 by the hydroelectric power plants and the average turbine flows producing the generation were estimated, assuming average and dry year conditions. Dry year conditions are only shown where hydroelectric generation is approximately 20 percent or more of the total generation in the ASA. Where more than one stream within an ASA includes hydroelectric plants, the average turbine flows of the plants in each of the streams have been aggregated to determine the flow utilized within the ASA, Where a single stream within an ASA includes a series of plants, only the largest turbine flow has been listed. Other plants in the series would also utilize portions of that flow. National Parks, Fish Hatcheries, BLM Lands, and National Forests One has to wonder why these categories were included in the National Assessment. Water consumed in national park areas in the region totals to only two MGD annually - an insignificant amount of water. National fish hatcheries require water withdrawals, but no water is consumed. The estimates for BLM lands include water consumed by wildlife, which for the region repre- sents about 60 percent of total water consumed on BLM lands. BLM lands constitute only' about six percent of the total basin lands, Water consumed by wildlife on the remaining 94 percent of lands is not accounted for. Water use accounted for on national forest lands is for recreation and miscellaneous uses. The amounts of water are not significant. The Missouri Basin Framework Report lists watershed protection projects as depleting average annual streamf10ws by about 300 MGD. These depletions are about 50 percent greater than the depletions on national parks, BLM and national forest lands, which account for only about 1.4 percent of the total water consumed in the region. Of the total of about 220 MGD consumed on public lands, about 60 MGD or over 25 percent is attributed to wildlife consumption of water, Man-Made Evaporation Evaporation losses from man-made impoundments for the National Assessment modified central case for the Missouri region are those computed for the Framework Report. These estimates were also used in the SRF.