boundaries (6.5 percent). The transient simulation model also suggests discharge primarily occurs through springs, followed by water well pumping; however, changes in water storage is heavily dependent upon the amount of monthly precipitation and water well pumping volumes. Policy Edwards Aquifer Authority regulates withdrawal permits, transfers, and groundwater conservation plans under authority granted by the Texas legislature. Groundwater law in the state of Texas is governed by the Rule of Capture, which gives landowners the right to pump groundwater beneath their land, with the exception of drilling a lateral well extending under a neighbor's property, wasting water, or pumping with the intention of causing harm to a neighbor's well. In order to construct a well to withdraw water from the Edwards Aquifer, however, a user requires a permit that is granted by the Edwards Aquifer Authority. Permits for existing users are determined by maximum historical use, taking into consideration the overall availability of water in the aquifer. Wells that produce less than 25,000 gallons per day, wells that are solely for the purpose of watering livestock, and a few other exceptions are considered exempt wells that do not require a permit. Permits for withdrawal can be transferred to another user, provided that the new use is beneficial and occurs within the boundaries of the Authority, with a few geographical exceptions. Groundwater conservation plans are required for permit holders who withdraw more than three acre feet per year (equivalent to 2,678 gallons per day), unless irrigators can prove more than 60 percent efficiency in their water use. Conservation plans require the use of Best Management Practices, as determined by the Edwards Aquifer Authority. In recharge zones of the aquifer permits are required to store regulated substances that could damage water quality. Additionally, The Texas Commission of Environmental Quality requires special permits for construction in the recharge zones of the aquifer. Conservation efforts Encompassing an area of 8 counties across south-central Texas including the City of San Antonio and its surrounding communities, the Edwards Aquifer is the main water supply source for the region, providing water for agricultural and industrial purposes and necessary water flow for endangered species habitat, as well as recreational purposes. As a result of a lawsuit filed by the Sierra Club under the Federal Endangered Species Act in 1991, the Edwards Aquifer Authority (EAA) was created to oversee the aquifer in its conservation efforts. The Texas Legislature directed