COST MINIMIZATION OF NUTRIENT REDUCTION IN WATERSHED MANAGEMENT USINGLINEAR-PROGRAMMING

Linear programming is applied to identify the least cost strategy for reaching politically specified phosphorus and total suspended solids r eduction targets for the Fox-Wolf river basin in Northeast Wisconsin. The programming model uses data collected on annualized unit reduction costs associated with five categories of sources of phosphorus and to tal suspended solids discharge in each of the 41 subwatersheds in the basin to determine the least cost management strategy. Results indicat e that: (1) cost-effective nutrient reduction requires careful selecti on of geographic areas and source categories to address throughout the watershed; (2) agricultural sources are the most cost-effective to ad dress in the basin; and (3) care should be exercised in setting nutrie nt reduction targets, given that there are likely to be significantly increasing marginal costs of nutrient reduction; the model predicts th at lowering the most restrictive target by 33 percent would cut reduct ion expenditures by about 75 percent. Policy implications of the model include support for the investigation and potential development of in stitutional arrangements that enable cost-effective nutrient reduction activities to occur, such as the creation of an agency with authority over a given watershed, coordinated watershed management activities, or nutrient trading programs.