Topic: Groundwater Tracing and Groundwater Flow Studies
Source: City of Austin
The Barton Springs segment of the Edwards Aquifer is an important resource for the region and understanding how the aquifer functions is critical to the conservation and preservation of the resource. Groundwater tracing is an important tool used to characterize the recharge areas, flow paths, groundwater velocities, dispersion, and fate of water in karst aquifers. Results of groundwater tracing demonstrate that a significant component of groundwater flow is rapid, discrete, and occurs in an integrated network of conduits, caves, and smaller dissolution features. Groundwater generally flows west to east within the recharge zone in secondary conduit systems that converge with northeast trending primary conduits defined by troughs in the potentiometric surface parallel to faulting and fracturing. Groundwater flow is very rapid from recharge features to wells and springs, with velocities ranging from 1 to 7 miles/day (1.6 – 11.3 kilometers/day) depending on hydrologic conditions. Tracing studies have further revealed the complexity of groundwater subbasins and the dynamic nature of the southern groundwater divide within the aquifer. This report presents an overview of 23 years of groundwater tracing from 1996 to 2017 in the Barton Springs segment of the Edwards Aquifer.