Average Annual Fulfillment of Instream Uses

Abstract

A significant demand for more formal recognition of instream water use has developed at national, regional, and state levels. This poses the need for a methodology to appraise the relative gains and losses which would arise from the imposition of a given instream use policy. Little prior effort has been directed toward this goal because of the difficulties involved in quantifying instream benefits. This paper does not attempt to place a dollar value on instream benefits, but does present a procedure for determining the average annual fulfillment of instream use. Case analyses are presented for ten streams which represent a wide range of hydrologic regimes encountered in the plains environment. Predictive functions developed in this study are useful in evaluating the relative instream use potential of different streams. These relations reflect the general shape of flow duration curves experienced in the plains region during the recreational year and the hydraulic characteristics of plains streams. They would not be applicable in regions exhibiting significantly different hydrologic and hydraulic characteristics.