10.2190/RDE4-N1UM-2J2P-07UX RDE4N1UM2J2P07UX 2 Estimating the Value of Improved Water Quality in an Urban River System 13 24 20020509 20020509 20020509 20020509 RDE4N1UM2J2P07UX.pdf http://baywood.metapress.com/link.asp?target=contribution&id=RDE4N1UM2J2P07UX 1 Kevin Croke Robert Fabian Gary Brenniman School of Public Health, University of Illinois at Chicago Improved water quality in the rivers of the metropolitan area is one of the benefits that can be derived from controlling combined sewer overflow in older large cities. This article estimates the value that cleaner rivers would have to Chicago citizens, and thus measures an important component of value to which the Chicago Deep Tunnel project can be expected to contribute. In a contingent value survey, average annual household values ranging from about $30 to $50 were observed for various degrees of improvement. An important result is that from two-thirds to nine-tenths of these reflect the intrinsic value of the rivers-nonuse values related to the existence of clean rivers or the option to use them in the future. A comparison with similar published studies confirms the credibility of the results. J. V. Krutilla, Conservation Reconsidered, <i>American Economic Review, 57</i>:4, pp. 777-786, 1967. W. H. Desvousges, V. K. Smith, and M. P. McGivney, <i>A Comparison of Alternative Approaches for Estimating Recreation and Related Benefits of Water Quality Improvements</i>, Economic Analysis Division, USEPA, Washington, D. C., 1983. R. G. Walsh, D. A. Greenley, R. A. Young, J. R. McKean and A. A. Prato, <i>Option Values, Preservation Values and Recreational Benefits of Improved Water Quality: A Case Study of the South Platte River Basin, Colorado</i>, Health Effects Research Laboratory, USEPA, Research Triangle Park, N. C., 1978. R. C. Mitchell and R. T. Carson, <i>An Experiment in Determining Willingness to Pay for National Water Quality Improvements</i>, USEPA, 1981. K. G. Croke and G. R. Brenniman, <i>Public Willingness to Pay for Improved Water Quality within Chicago Land Underflow Plan Area</i>, School of Public Health, University of Illinois at Chicago, 1985.