HOW MUCH HAVE WE LOST? AFFECTS OF URBANIZATION AND MINING ON AN ALLUVIAL AQUIFER IN CENTRAL TEXAS

The Brazos River Alluvium aquifer near Waco, Texas has been physically impacted by anthropological influences. Urban growth atop the alluvial aquifer has covered recharge areas with less permeable surfaces restricting groundwater recharge. Urban land use has also decreased prospective production potential by limiting possible well locations. The extraction of sand and gravel has removed some of the most productive areas within the aquifer and either left the aquifer directly exposed to surface impacts or replaced the aquifer with other materials. Surface mining that removes aquifer framework directly affects aquifer functionality and current regulations do not require restoration. Aquifer restoration has predominantly been studied from a groundwater quality perspective with minimal research focused on physical degradation. Aquifer restoration that targets physical degradation may be equally important in managing groundwater resources for the future. In order to restore aquifer functionality, the anthropological effects were first identified then quantified. Assessment of the impacts and potential solutions for restoring the Brazos River Alluvium aquifer were investigated using GIS, remote sensing, and modeling. Geospatial information was derived using GIS and remote sensing techniques; while model inputs were collected from laboratory analysis of unconsolidated materials, data collected from the field, and previously published data. A water budget analysis of current aquifer conditions and pre urbanization conditions can provide better understanding to the effect of urbanization and mining. The results from the Brazos River Alluvium aquifer study are representative of similar shallow aquifer systems impacted by surface excavation and urban development.