ASSESSING THE ECONOMIC BENEFITS OF GROUND WATER FOR ENVIRONMENTAL POLICY DECISIONS1

ABSTRACT: The full range of environmental and economic services of ground water need to be accounted for in policy decisions. Non-recognition of these services imputes a lower value for the ground water resource in establishing policies. We describe a conceptual framework for identifying and measuring the economic value of groundwater. The valuation framework links changes in physical characteristics of ground water to services provided by ground water and the economic effects of changes in ground water services. In addition to the framework, we develop a general protocol to follow for assessing the benefits of ground water policies. Application of the protocol will aid in establishing structure and consistency across policy assessments and improve the accuracy and completeness of benefit estimates, avoid double-counting problems, and eliminate duplication of ground water valuation efforts.     

THE ECONOMIC EFFECTS OF CHANGES IN WATER USE IN THE TUCSON BASIN,ARIZONA1

ABSTRACT: The ground water in the Tucson basin is being drawn faster than it is replenished by nature. The water table is falling, giving rise to several conflicts between water users in the basin. At present, several lawsuits are in progress, including an action by the Papago Tribe against some of the major water users in the basin. Largely because of these difficulties, the State Legislature has established a commission to make proposals for the reform of Arizona's ground water law. The pattern of water use in the basin will undoubtedly be changed by the outcome of the present litigation and the coming reform of Arizona's ground water law. This paper describes how water use in the basin might be affected by changes in the availability of water and gives an account of the effects that these changes in water use could have on the region's economy. The paper concludes that the water problems of the Tucson basin will have little effect on the region at large and that these problems are simply a matter for the Indians and the other water users in the basin to sort out amongst themselves.     

MAXIMIZING THE VALUE OF INFORMATION FOR GROUND WATER PROTECTION: THREE TEST CASES1

ABSTRACT: Public awareness of the importance of protecting the nation's water supplies is growing. Recent studies have shown a substantial increase in the perceived value of protecting water supplies for future use. In the Northeast, much of the water supply comes from ground water. This paper examines three test cases, each with different approaches for using geographic information systems (GIS) for ground water protection planning. In Wellfleet, Massachusetts, build-out scenarios were used to support regulatory and land acquisition decisions for siting a public water supply well. In Hadley, Massachusetts, the focus was on a decision support model for septic suitability assessment in support of regulatory efforts and infrastructure expansion. For Cortland County, New York, an interactive graphic user interface was created to facilitate the manipulation and recombination of a large volume of data by county officials to target ground water pollution prevention efforts. As personal computers become more powerful and inexpensive, and GIS data become more readily available, community and county governments are turning to GIS as a tool for developing comprehensive resource protection plans. Once appropriate data are input, a GIS can effectively and efficiently be used to derive outcomes of various land use plans and regulations.     

PLANNING LEVEL ESTIMATES OF THE VALUE OF RESERVOIRS FOR WATER SUPPLY AND FLOW AUGMENTATION IN NEW HAMPSHIRE1

: In general, the choice among reservoirs for water supply or flow augmentation is a multiobjective problem. Choices are based in part on the yield available from water supply reservoirs or, in the case of flow augmentation reservoirs, on the increase in low flows at downstream locations. Detailed estimates of these effects may be too costly for basin planning purposes. Thus this paper presents methods for rapid estimation of those quantities for New Hampshire. For water supply reservoirs, a composite empirical relation between Y95 (the draft available 95 percent of the time) and storage ratio, S*, is developed from previous studies in the region. For flow augmentation reservoirs, empirical relations between S* and degree of regulation, R*, are applied to each upstream regulating reservoir. Values of regulation arc then summed and divided by the mean flow at the downstream reach of interest. This parameter, (ΓR)*, is then related to increase in flow available 95 percent of the time by an empirical relation.