NUTRIENT WATER POLLUTION IS AMONG THE NATION'S MOST VEXING ENVIRONMENTAL PROBLEMS. IN MANY AREAS, INCLUDING THE UPPER MISSISSIPPI RIVER BASIN (UMRB), THE MAIN THREAT IS NITROGEN AND PHOSPHORUS RUNOFF FROM AGRICULTURAL OPERATIONS. AS A RESULT, THE NRCS OPERATES PROGRAMS THAT SUPPORT PRACTICES FOR IMPROVING WATER QUALITY. THE SIZE OF EXPENDITURES AND PERSISTENCE OF WATER POLLUTION PROBLEMS RAISE SEVERAL FUNDAMENTAL QUESTIONS: ARE THE ENVIRONMENTAL BENEFITS FROM THE PROGRAMS LARGE ENOUGH TO JUSTIFY THEIR COSTS? WOULD THE BENEFITS OF ADDITIONAL EXPENDITURES JUSTIFY THE COSTS? CAN NRCS'S CONSERVATION PROGRAMS BE IMPROVED TO DELIVER MORE ENVIRONMENTAL VALUE FOR THE BUDGET?TO ADDRESS THESE QUESTIONS, WE BUILD A MODEL FOR VALUING WATER QUALITY CHANGES IN THE UMRB THAT ARISE FROM NRCS PROGRAMS. THE MODEL WILL ALLOW US TO: (A) MEASURE HOW FIELD-LEVEL REDUCTIONS IN NUTRIENT POLLUTION FROM SUPPORTED PRACTICES TRANSLATE INTO DOWNSTREAM AMBIENT IMPROVEMENTS; (B) ASSIGN ECONOMIC VALUES FOR IMPROVEMENTS THAT OPERATE THROUGH PROPERTY MARKETS AND PEOPLE'S RECREATION BEHAVIOR; AND (C) ASSESS THE UMRB-WIDE AGGREGATE BENEFITS FROM SPECIFIC POLICIES.