Cropland management versus dredging: An economic analysis of reservoir sediment management

Abstract

Abstract Erosion of agricultural cropland has been identified as a major source of sediment accumulating in water reservoirs. Emphasis is increasingly on finding the most cost-effective ways to control soil erosion to reduce reservoir sedimentation. In this study, biophysical and economic models for the Tuttle Creek Lake watershed in northeastern Kansas were integrated to determine if implementation of alternative cropland management strategies to reduce reservoir sediment are more cost-effective than dredging. In the Tuttle Creek Lake watershed, we found that if the marginal costs of agricultural best management practices (BMP) implementation become >$6.90/t of sediment reduction, then dredging becomes the economically preferred alternative. Meeting this cost requires that BMP in the form of filter strips and no-till cultivation are implemented in a targeted, cost-effective manner, not in a random pattern of voluntary adoption that may characterize BMP adoption in some watersheds. Although reservoir dredging is clearly expensive, our results show that it is not entirely cost-prohibitive on an annualized per unit basis.