ECONOMIC VALUE OF INSTREAM FLOW IN MONTANA BIG-HOLE AND BITTERROOT RIVERS

Instream flow is valuable to recreationists who rely on flows for fish ing, boating, and other forms of river recreation. Instream flow is al so valuable to many members of society, whether they visit the rivers or not, because flows maintain ecosystem stability and associated fish and wildlife habitat. This study estimates the economic value of thes e recreation and preservation benefits along the Big Hole and the Bitt erroot Rivers in Montana. Valuation and participation information was obtained from recreationists who were interviewed along the rivers, an d from households that were sampled using mail and phone surveys. Both dichotomous-choice and open-ended contingent valuation questions were used in these surveys to estimate the value of instream flow. In addi tion, methodological issues of additivity of preservation values and a pportionment of total value into use and nonuse categories were invest igated. Results indicate substantial economic value for maintaining in stream flows above minimum levels, with most of the value attributable to preservation motives.