As part of an ongoing partnership with the Texas Water Development Board (TWDB), The District conducts aquifer-wide sampling of groundwater sites and has done so annually since 1998. The TWDB funded laboratory analyses of these samples including major constituents, dissolved trace metals, and nutrients.

A comprehensive list of groundwater constituents was also analyzed from 28 wells and six springs in 2001. This study was included in an EPA 319h grant administered by the Texas Natural Resource Conservation Commission to study non-point pollution. The results of that study indicate that groundwater contaminant levels in most of the sampled wells and springs are low compared to EPA maximum contaminant levels. Though this data provides a good base line of water quality data, samples were collected during one period of flow conditions. Other agencies, such as the City of Austin and the U.S. Geological Survey, are also actively involved with water-quality studies.