New Mexico Geological Society Annual Spring Meeting — Abstracts

The Bosque del Apache National Wildlife Refuge in south-central New Mexico is the site of seasonal wetlands that support habitat for year-round and migratory wildlife. Water is managed at the Refuge to support agricultural plots, riparian zones, and the needs of endangered species. The Refuge currently uses a monthly time step model that integrates a variety of estimated and empirical data to develop the hydrologic budget for irrigation water. However, there have been no direct measurements of how much water is infiltrating from managed wetlands into the shallow ground water. It is important to improve the accuracy of water budget estimates by developing infiltration rates based on empirically derived data. In order to accomplish this goal, we studied 4 hydrologically distinct wetlands (different sizes, soil textures, and water management) comprised of agriculture land, forested grass land, and flood plain mixed with conifer forest and riparian vegetation. Regularly collected data included weekly flow measurements at 4 inflow and 4 outflow structures, daily staff plate readings, and weekly ground water levels at 20 monitoring sites. These data are being integrated into a wetland ArcGIS tool to quantify the Refuge wetland water budget. The wetland units show average increases in water table elevation of 1.61-2.67 survey feet after surface water introduction over the study period. Infiltration rates are being calculated for the 4 studied wetland units and scaled out to represent all Refuge wetlands to create a more accurate water budget.