Water Resources Research Act Program

Details for Project ID 2007TX264B

Evaluating the Impacts of Brush Clearing on Recharge of a Karst Aquifer

Institute: Texas
Year Established: 2007 Start Date: 2007-03-01 End Date: 2008-02-29
Total Federal Funds: $5,000 Total Non-Federal Funds: $13,002

Principal Investigators: Corinne Wong, Jay Banner

Abstract: Increasing water quality and quantity are of importance to private and government managerial bodies, especially in sprawling urban areas in central Texas. Brush removal as a land management practice to improve water quality and quantity is ubiquitous among private and government managerial agencies. However, large amounts of money are allocated to brush removal projects while effectiveness in still in question. My study will address how the removal of ashe juniper (Juniper ashei) on the landscape above Natural Bridge Caverns affects recharge by evaluating changes in drip rate and drip water chemistry in a cave directly beneath the cleared area. It is my hypothesis that brush removal will increase recharge and result in greater supply to the flow paths feeding the studied drip sites. This will be reflected in an increased drip rate and water chemistry that indicates shorter water residence times in bedrock. Specifically, lower Mg/Ca and Sr/Ca ratios and higher 87Sr/86Sr ratios, which closer match the ratio of the soil rather than the host rock, are expected. These results will be pertinent to current land management decisions in whether or not to support brush removal on recharge lands as an efficient practice to increase water quantity to underlying aquifers.