Floridan Aquifer System (FAS) Groundwater Availability Study

Science Center Objects

The Floridan Aquifer System (FAS) Groundwater Availability Study (https://fl.water.usgs.gov/floridan/) provides numerous benefits, including an updated hydrogeologic framework, regional and subregional water budgets, and a modern, system-wide, groundwater flow model that may be used to quantitatively assess the effects of human and environmental stresses.

The USGS Groundwater Resources Program is assessing groundwater availability in areas of critical importance across the Nation. The Floridan Aquifer System (FAS) Groundwater Availability Study (https://fl.water.usgs.gov/floridan/) is a part of this program. This study will provide numerous benefits, including an updated hydrogeologic framework, regional and subregional water budgets, and a modern, system-wide, groundwater flow model that may be used to quantitatively assess the effects of human and environmental stresses. The Floridan Aquifer System Water Availability Model (FASWAM) will be a key tool developed during the study.

Floridan aquifer system in Florida and parts of Georgia, Alabama, Mississippi, and South Carolina

Floridan aquifer system in Florida and parts of Georgia, Alabama, Mississippi, and South Carolina

 

Potential benefits of the FAS groundwater availability study:

Revised regional hydrogeologic framework: A revised hydrogeologic framework of the FAS will replace the disparate local and subregional frameworks that have been developed since the Regional Aquifer-System Analysis (RASA) study published in 1986. Publication of databases of hydrogeologic properties will be a valuable resource for current and future studies.

Development of a modern, system-wide, groundwater flow model: A groundwater flow model of the entire FAS has not been developed since the RASA study. Development of this newer model will advance regional understanding of the aquifer system and could provide the platform for multi-state and multi-jurisdictional resource management.

Improved understanding of the groundwater budget: Independent and model-simulated water budgets for the FAS will provide more highly resolved (in space and time) estimates of aquifer recharge, discharge (groundwater withdrawals, evapotranspiration, spring flow, baseflow), and changes in storage compared to existing system-wide estimates.

Improved understanding of regional surface impacts: The effects of meteorological conditions, such as spatial and temporal rainfall patterns, and groundwater withdrawals from the FAS can impact wetland, lake, stream, spring flow, and water-table dynamics. Better understanding of how such effects are manifest at the regional scale will help resource managers develop more effective guidelines and regulations, and provide information for mitigation of potential threats to the sustainable management of the aquifer system.

Assessment of the potential impact of climate and landscape change: The effects of potential climate change and sea-level rise as well as changing water-use practices attributable to landscape change may affect patterns of groundwater flow and storage. The effects of these potential future stresses on the FAS will be assessed at the regional scale.

Recent activity

Technical Team meetings of the North Florida Regional Water Supply Partnership (NFRWSP) (http://northfloridawater.com/) are ongoing. The purpose of the Technical Team is to provide guidance on the development of a regional groundwater flow model of north Florida and southeast Georgia (NFSEG) that will be used to assess regional effects of groundwater withdrawals and provide a framework for development of subregional models. Discussions focus on development of a watershed model using the Hydrological Simulation Program—Fortran (HSPF), which will be used to provide estimates of groundwater recharge to the NFSEG groundwater model. The USGS has provided approved data and participated in discussions about hydrogeologic mapping. Collaboration and the exchange of data between State of Florida Water Management District (WMD) scientists working on the NFSEG model and USGS scientists working on the Floridan Aquifer System Groundwater Availability Study are ongoing and will continue as a means of enhancing the success of both efforts. The NFRWSP is a collaborative process—among the St. Johns River and Suwannee River WMDs, Florida Department of Environmental Protection, local governments, concerned residents, and other stakeholders—to help address regional water-supply issues.