Data about flow rate, fishing intensity, and expenditures made by anglers can be used to capture some of the recreational value of waterways in economic terms in a way that avoids a number of the weaknesses of the most commonly used tools such as the contingent valuation method. Furthermore, recreational fishing may spur more economic activity than competing uses of riverine flows such as agriculture. This suggests that potential opportunity cost in regards to recreation ought to be a factor considered (...) in management decisions. (shrink)