THE PROPOSED RESEARCH ADDRESSES THE ISSUE OF IRRIGATION WATER USE EFFICIENCY/CONSERVATION FOR THE REPUBLICAN RIVER BASIN WHICH IS AN IMPORTANT AGRICULTURAL WATERSHED FOR THE STATES NEBRASKA, COLORADO AND KANSAS. IT EVALUATES THE RELATIVE EFFECTIVENESS OF BEHAVIOR-BASED WATER CONSERVATION PROGRAMS VERSUS TECHNOLOGY-BASED WATER CONSERVATION PROGRAMS, AND ANALYZES DRIVERS AND INHIBITING FACTORS TO BEHAVIORAL CHANGES IN IRRIGATION WATER USE. THE OVERALL OBJECTIVE FOR THIS APPLICATION IS TO CONDUCT A BASIN-WIDE STUDY TO BETTER UNDERSTAND CHANGES IN FARMERS' BEHAVIOR TO REDUCE IRRIGATION WATER USE THROUGH PROVISION OF TECHNICAL ADVICE AND SOCIAL NORMS INTERVENTIONS. WE PARTNER WITH THE LOCAL WATER MANAGEMENT DISTRICTS WITHIN THE REPUBLICAN RIVER BASIN TO IMPLEMENT A SERIES OF EXPERIMENTAL TREATMENTS DESIGNED TO AUGMENT EXISTING TECHNOLOGY-BASED WATER CONSERVATION PROGRAMS. WE CONSIDER PROVISION OF THE FOLLOWING SOCIAL-NORM MESSAGES SENT TO FARMERS BY MAIL: TREATMENT 1: IRRIGATION METER ONLY (CONTROL EXPERIMENT); TREATMENT 2: IRRIGATION METER AND TECHNICAL ADVICE; TREATMENT 3: IRRIGATION METER AND PROSOCIAL PREFERENCES; TREATMENT 4: IRRIGATION METER AND NEIGHBORLY COMPARISONS; TREATMENT 5: IRRIGATION METER, TECHNICAL ADVICE, PROSOCIAL PREFERENCES, AND NEIGHBORLY COMPARISONS. THE REQUISITE DATA WILL BE OBTAINED FROM EXISTING IRRIGATION WATER WITHDRAWAL DATABASES MAINTAINED BY LOCAL WATER DISTRICTS, MAILED FIELD SURVEYS AND IRRIGATION FLOWMETER READINGS DURING THE PERIOD OF STUDY. DATA WILL BE ANALYZED FOR RELATIVE EFFECTIVENESS, HETEROGENEITY AND DURABILITY OF THE TREATMENTS. DATA FILE DE-IDENTIFICATION, DOCUMENTATION VERIFICATION, AND PUBLIC ARCHIVING WILL BE PROVIDED. THE PROPOSED RESEARCH IN THIS APPLICATION IS SIGNIFICANT BECAUSE APPLICATION OF THE RESULTANT SOCIAL-NORM-BASED CONSERVATION PROGRAMS IS EXPECTED TO BE LOW-COST AND LEAD TO GREATER ADOPTION OF IMPROVED IRRIGATION WATER USE IN THE REPUBLICAN RIVER BASIN AS WELL AS ASSIST IN THE LONG-TERM MANAGEMENT OF WATER RESOURCES IN LINE WITH THE USDA POLICY ON CONSERVATION OF WATER RESOURCES.