SWAT-Based Evapotranspirative Water Conservation Analysis Performed on Irrigated Croplands to Determine Potential Regional Water Savings

Abstract

Significant water savings might be realized, regionally and nationally, if an additional fraction of cultivated land were converted to a more effective form of irrigation (e.g., from furrow flooding to center pivot or drip, where feasible). To quantify potential savings, the ArcMap-based USDA Agricultural Research Service (ARS) Soil and Water Assessment Tool (SWAT) software was used to model hydrologic budgets in the San Miguel Creek watershed, Texas; findings were applied to regionally similar agricultural land in the Edwards Aquifer Groundwater Conservation District and Texas State Regional Water Planning Area L (RWPA-L). Up to 26.1 and 99.8 million m3 of potential agricultural water savings were identified in these two areas, respectively. The straightforward approach can be used to predict water demand and potential water savings in closed rivers basins; across borders; or in other areas in which agricultural irrigation is prevalent, water scarcity may be a concern, or competing rural/urban interests persist among various user groups.