10.2190/5M3M-54B2-QB5K-DRR4 5M3M54B2QB5KDRR4 6 Estimation of Instream Flow Requirements for Fish 381 396 20020509 20020509 20020509 20020509 5M3M54B2QB5KDRR4.pdf http://baywood.metapress.com/link.asp?target=contribution&id=5M3M54B2QB5KDRR4 4 A. R. Rao T. Voeller J. W. Delleur A. Spacie Purdue University, Indiana Flows required for sustaining fish population in a stream are examined in this study. The instream flow incremental methodology (IFIM) which has been developed for estimating these flows requires data which are not commonly available and are expensive to acquire. Other methods to estimate instream flows, which are based only on flow rates, do not consider the characteristics of the fish population in the stream and hence are unrealistic. A modification of the IFIM is proposed in this study. Various factors which are involved in the modification are investigated. Based on these investigations, a method which is much less data intensive than the IFTM but which gives results of the same order of magnitude as the IFIM is proposed. The method is illustrated by using data from streams in Indiana. Indiana Department of Natural Resources, <i>Indiana Canoeing Guide</i>, Indianapolis, Indiana, 1983. K. P. Singh, S. M. Broeren, and R. B. King, <i>Interactive Basinwide Model for Instream Flow and Aquatic Habitat Assessment</i>, Illinois Department of Energy and Natural Resources, State Water Survey Division, Surface Water Section, University of Illinois, Champaign, Illinois, 101 pp., 1986. E. E. Herricks, J. B. Stall, J. W. Eheart, A. E. Libby, S. F. Railsback, and M. J. Sale, <i>Instream Flow Needs Analysis of the Little Wabash River Basin</i>, Environmental Engineering Series No. 61, Department of Civil Engineering, University of Illinois, Champaign, Illinois, 150 pp., 1980. J. A. Fritschen, R. T. Milhous, and J. Nestler, <i>Measuring Resource Potential for River Recreation</i>, in J. S. Popadic, D. I. Butterfield, D. H. Anderson, and M. R. Popadic (eds.), proceedings of the National River Recreation Symposium, Baton Rouge, Louisiana, pp. 484-494, 1984. A. D. Feldman, HEC Models for Water Resources Simulation: Theory and Experience, <i>Advances in Hydroscience, 12</i>, pp. 297-423, 1981. K. Bovee, <i>A Guide to Stream Habitat Analysis using the Instream Flow Incremental Methodology</i>, Instream flow information paper: No. 12, United States Fish and Wildlife Service, Fort Collins, Colorado, 248 pp., 1982. R. T. Milhous, <i>The Physical Habitat-Aquatic Population of Relationship</i>, presentation at the 1988 meeting of the Colorado-Wyoming Section of the American Fisheries Society, 1988. J. Nestler, <i>Evaluating Physical Habitat as a Function of Discharge Using Existing Numerical Models</i>, in the Instream Flow Chronicle, A Training Announcement, Vol. VII, No. 1, Colorado State University, Fort Collins, Colorado, pp. 1-2, 1990. R. T. Milhous, <i>The Quantification of Instream Flow Rights</i>, for presentation at the 1986 winter meeting of the American Society of Agricultural Engineers, Paper No. 86-2625, Chicago, Illinois, December 1986.