EFFECTS OF LAND COVER CHANGE ON STORM WATER RUNOFF AT THE KISSING TREE DEVELOPMENT IN SAN MARCOS, TEXAS

Hays County, Texas, including the City of San Marcos, has experienced a rise in infrastructure and development to accommodate the fastest growing urban area in the United States. Although increased development is common throughout the state, Southcentral Texas’ urban development is concentrated near and on aquifer recharge zones. Recently, several large-scale, single family developments have been approved by the San Marcos City Council for development on the Edwards Aquifer recharge and transition zones. One of these developments, Kissing Tree, and an associated golf course, is actively under construction west of Hunter Road in southwestern San Marcos. Although San Marcos has codes and ordinances that currently govern development on the recharge and transition zones, ambiguity exists that allows for inconsistency and loopholes to be made to these regulations. These loopholes serve to increase development but fail to consider the environmental impact had in a karst terrain. Any development will result in landscape alteration, creating a more impervious surface. The purpose of this proposed research is to evaluate potential changes to surface hydrology as a result of land use and land cover changes resulting from urban development. The GIS-based, hydrologic model, SWAT, will be used to assess alterations in effective flow in storm water runoff as a product of land cover changes. Although active research is being done, accurate urban hydrologic modeling at high spatial and temporal resolutions remains a significant challenge in hydrologic studies, due to the complex nature of urban hydrology.