Evaluating Benefits and Costs of Changes in Water Quality

Water quality affects a variety of uses, such as municipal water consumption and recreation. Changes in water quality can influence the benefits water users receive. The problem is how to define water quality for specific uses. It is not possible to come up with one formal definition of water quality that fits all water uses. There are many parameters that influence water quality and that affect benefits to water users. This paper examines six water quality parameters and their influence on six water uses. The water quality parameters are clarity, quantity, salinity, total suspended solids, temperature, and dissolved oxygen. Changes in these parameters are evaluated to determine values for municipal, agricultural, recreational, industrial, hydropower, and nonmarket uses of water. Various techniques can be used to estimate nonmarket values for changes in water quality, such as the travel cost method, the contingent valuation method, and the hedonic property method. The data collected on changes in water quantity per acre-foot and its effect on recreationistsÆ benefits were analyzed by using multiple regression in a meta-analysis. Results from the regression were used to analyze changes in consumer surplus for particular activities and uses for an additional acre-foot of water. Information in tables is included to provide empirical evidence as to how certain water quality parameters affect a particular use. The tables provide values from previous studies and the valuation techniques used in each study. From these values, we find mean values of changes in water quality and how this change monetarily affects the use in question.