Data and information reveal that the Edwards Aquifer between Lady Bird Lake (the Colorado River) in Austin, Texas and the "groundwater divide" near Kyle, Texas discharges to 2 major springs: Barton Springs and Cold and Deep Eddy Springs. The long-term mean discharges for the springs are 51 cubic feet per second and 5.5 cubic feet per second, respectively. The source for Cold and Deep Eddy Springs probably represents Dry Creek in the Rollingwood, Texas area and a small amount of recharge water from Barton Creek.
Additional springflow, which periodically discharges from the lower reach of Barton Creek immediately upstream from Barton Springs, varies from zero when Barton Springs is flowing about 50 cubic feet per second to about 5 cubic feet per second during extreme high-flow conditions at Barton Springs. Two streamflow gain-loss studies on the Colorado River document any other discharges from the Edwards Aquifer to the Colorado River to be nonexistent or minor.
A recharge-discharge water budget for a 32-month period reveals that the total discharge from Barton Springs, Cold and Deep Eddy Springs, the lower reach of Barton Creek, and groundwater pumpage is about 3% less than the surface recharge—a value within the potential error of the measurements. Additionally, for the budget period, recharge within the main channels of the 6 major streams crossing the recharge area account for a minimum of 75% of total recharge. Therefore, long-term recharge within the recharge area from overland flow or tributaries to the main channels represents a maximum of 25% of total recharge, a value equivalent to a mean depth of 2.1 inches per year over the 90-square-mile recharge area, or no more than 6.6% of the long-term mean precipitation of 32 inches per year over the recharge area.
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).