Changes in urban land use throughout the Edwards Aquifer: A comparative analysis of Austin, San Antonio, and the Interstate–35 corridor

Abstract

Due to the vulnerability of the Edwards Aquifer to urban development, policy measures have been implemented to protect the important water resource in South–Central Texas. This paper analyzed land use change trends across different portions of the Edwards Aquifer to better understand the degree to which protective measures influenced aquifer urbanization rates. Specifically, the National Land Cover Database was used to quantify urban development within the contributing and recharge zones of the Edwards Aquifer across Bexar, Travis, Williamson, Comal, and Hays counties for three time periods: 2001–2006, 2006–2011, and 2011–2016. Bexar County exhibited the greatest reduction in the rate of urbanization within the recharge zone although the percentage of the zone developed remained the highest. Conversely, the pace of recharge zone development in Travis and Williamson County decreased less rapidly, but the percentage of the zone urbanized was lower. Limited urban development was observed across the aquifer in Comal and Hays County during the study period. Overall, the consistent declining rate of urbanization throughout the sensitive Edwards Aquifer recharge zone suggests that the policies protecting the aquifer were largely effective, particularly given the rapid pace of urban growth throughout the region.