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Several Federal agencies have historically had responsibilities for conducting assessments of the Nation's water resources. The U.S. Geological Survey (USGS), U.S. Army Corps of Engineers, U.S. Department of Agriculture's Soil Conservation Service (SCS), and U.S. Environmental Protection Agency (EPA) and its predecessor agencies, among others, have conducted studies assessing the current situation and future prospects for water in particular regions of the country. Responsibility for national water assessments was assigned to the U.S. Water Resources Council (WRC) by the Water Resources Planning Act of 1965. With the demise of the WRC in 1981, several member agencies have attempted to take over parts of the WRC role and improve their own analyses. USGS began to publish an annual National Water Summary in 1984. The first three annual reports, Water-Supply Paper 2250 (USGS 1984), 2275 (USGS 1985), and 2300 (USGS 1986), have been used extensively in the preparation of this Assessment. In some cases, extended portions of text have been lifted from those reports; in other cases, topics are presented in the same order. The 1986 Summary (USGS 1988) was published after preparation of this report was completed. Similarly , EPA publishes biennial reports to Congress on the National Water Quality Inventory. Information from these reports has also been extracted for this Assessment. The Forests and Rangelands Renewable Resources Planning Act of 1974 (88 Stat. 476, as amended; 16 U.S.C. 1601-1614) (RPA) directs the Secretary of Agriculture to conduct an assessment of the Nation's forest and rangeland resource situation covering all renewable resources within the purview of the Forest Service. Water is one of the renewable resources. RPA legislation also directed the Forest Service to follow two principles in conducting assessments. First, assessments were to analyze the resource situation from a national perspective-including all ownerships, public and private. Second, the Forest Service was to use, to the extent practicable, information collected by other public agencies on the resources studied. This report faithfully follows that direction. This report has nine chapters beginning with a broad overview of the current water resource situation in the United States. The extensive reference citations are a "road map" directing readers to more detailed discussions of individual topics in the reports of other agencies. One requirement of the RPA legislation is an analysis, looking 50 years into the future, of prospective demands and supplies of each resource. Chapter 3 contains an analysis of historical trends in withdrawals and consumption and projections to 2040 based on data from USGS and SCS. In this report, withdrawals and consumption are treated as two different forms of demand for water. Both forms of demand are projected independently of supplies. Consumption is used in later chapters as the preferred definition of demand. Chapter 4 contains an analysis of historical trends in water supplies and projections to 2040 based upon generalized water budgets. The projections of demand and supply are the results of new analyses by the author. It is important to recognize that trends projected in these chapters are not in any sense "most likely." Rather, they portray what might occur if factors determining water resource management and use continue unchanged from those in effect since 1970. Obviously, projections of past trends will demonstrate conflicts between the level of consumptive use demanded and the level of supply projected to be available. A discussion of those conflicts is presented in Chapter 5 and the social, environmental, and economic implications of those conflicts is presented in Chapter 6. Chapters 5 and 6 also contain analyses of some alternative future scenarios for water resources having the potential to alter the demand and supply projections which were based upon recent trends. Although projections of consumption demands and available supplies differ-creating either surpluses or shortages-these differences will not really occur. Rather, the economy will function and prices for water and other goods and services (such as water treatment) will change, thereby bringing supplies and demand into equilibrium. These adjustments, if not planned in advance, can lead to undesirable consequences. Water resource users and managers have opportunities to alter use and management practices inherent in the recent trends to achieve a more desirable future water resource situation. These opportunities are outlined in Chapter 7. Similarly, there are some obstacles-economic, social, environmental, institutional, and regulatory-to taking advantage of opportunities. These obstacles are discussed in Chapter 8. Chapter 9 discusses implications of these opportunities and obstacles on Forest Service resource management and research programs, providing guidance for agency strategic planning.


General Technical Report RM-177