A study of water level data collected during the 2009 drought was conducted to determine if there is a hydrologic connection between the San Antonio segment and Barton Springs segment of the Edwards Aquifer. These results showed con-tinuity in the direction of groundwater flow along a preferential groundwater flow zone from San Marcos Springs to Barton Springs during the drought. Using a USGS MODFLOW model, the flow passing San Marcos Springs and flowing toward Bar-ton Springs was estimated at about five cfs.
Near the city of Kyle, major discontinuities in hydraulic gradient and water levels were evident, which indicate a zone of relatively low transmissivity. Southwest of Kyle, an area of nearly flat water levels exists and is believed to be a zone of high transmissivity. Faults do not appear to be a controlling factor between the zones of relatively high and low transmissivity nor blockage or conduits of groundwater flow. Rapid population growth and increased water demands suggests a continual groundwater level monitoring program between San Marcos Springs and Buda to provide data for future local and regional hydrogeologic analyses.
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Copyright (c) 2011 Larry F. Land, Brian B. Hunt, Brian A. Smith, Paula Jo Lemonds