WATERSHEDSS - A DECISION-SUPPORT SYSTEM FOR WATERSHED-SCALE NONPOINT-SOURCE WATER-QUALITY PROBLEMS

A significant portion of all pollutants entering surface waters (strea ms, lakes, estuaries, and wetlands) derives from nonpoint source (NPS) pollution and, in particular, agricultural activities. The first step in restoring a water resource is to focus on the primary water qualit y problem in the watershed. The most appropriate NPS control measures, which include best management practices (BMPs) and landscape features , such as wetlands and riparian areas, can then be selected and positi oned to minimize or mitigate the identified pollutant(s). A computer-b ased decision support and educational software system, WATERSHEDSS (WA TER, Soil, and Hydro-Environmental Decision Support System),has been d eveloped to aid managers in defining their water quality problems and selecting appropriate NPS control measures. The three primary objectiv es of WATERSHEDSS are (1) to transfer water quality and land treatment information to watershed managers in order to assist them with approp riate land management/land treatment decisions; (2) to assess NPS poll ution in a watershed based on user-supplied information and decisions; and (3) to evaluate, through geographical information systems-assiste d modeling, the water quality effects of alternative land treatment sc enarios.