The Edwards Aquifer provides vital water resources for economic development, public and domestic water supplies, and ecosystem services for central Texas and the greater San Antonio area. City planners and water managers need high-quality water-resource information to make informed decisions for water availability, water quality, aquifer protection, and infrastructure growth. The U.S. Geological Survey (USGS) Urban Hydrology Network (UHN) encompasses monitoring of surface water and groundwater at appropriate spatial and temporal scales to provide insight to complex hydrologic issues in a region impacted by urbanization, population growth, and climate change.
The UHN provides high resolution, real-time, continuous monitoring data, augmented with periodic water-quality sampling, and deploying cutting-edge technologies to provide new information and tools for the public and stakeholders including:
Click on image for larger view. From Musgrove and others, 2011.
Changes in Nitrate Concentrations and Sources in Edwards Aquifer Groundwater
The Edwards aquifer region is undergoing rapid growth, particularly in urban areas such as San Antonio and Austin. Such growth can increase anthropogenic sources of nitrate to groundwater. Nitrate is an important nutrient, but elevated concentrations may affect aquifer ecosystems. Additionally, consumption of drinking water with elevated nitrate concentrations may have adverse health effects.
Timescales and Drivers of Water-Quality Change in the Edwards Aquifer
Groundwater quality changes over time. Long term monitoring of those changes helps groundwater resource managers understand and protect the aquifer. This study combined high-frequency monitoring and discrete sample collection of a range of geochemical constituents which enhances our ability to understand the timescales of groundwater quality change.
Continuous Monitoring Tracks Local Surface-Water and Groundwater Connections
USGS "super sites" examine the dynamic connection between urban stormwater runoff and recharge to shallow groundwater of the Edwards aquifer. These sites monitor both streamflow and groundwater levels and are sites of water-quality sample collection during periods of groundwater recharge.
Urban and Rural Nitrate Sources to the Edwards Aquifer
Groundwater nitrate data from continuous water-quality monitoring, combined with discrete water-quality samples from surface-water and groundwater, provide insight into nitrate contributions to the aquifer from rural and urban sources.