Groundwater-flow budget for the lower Apalachicola-Chattahoochee-Flint River Basin in southwestern Georgia and parts of Florida and Alabama, 2008–12

Abstract

For more information on the USGS-the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment-visit https://www.usgs.gov or call 1-888-ASK-USGS.For an overview of USGS information products, including maps, imagery, and publications, visit https://store.usgs.gov.Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner.Suggested citation: Jones, L.E., Painter, Jaime, LaFontaine, Jacob, Sepulveda, Nicasio, and Sifuentes, D.F., 2017, Groundwater-flow budget for the lower Apalachicola-Chattahoochee-Flint River Basin in southwestern Georgia and parts of Florida and Alabama, 2008-12 By L. Elliott Jones, Jaime Painter, Jacob LaFontaine, Nicasio Sepulveda, and Dorothy F. Sifuentes AbstractAs part of the National Water Census program in the Apalachicola-Chattahoochee-Flint (ACF) River Basin, the U.S. Geological Survey evaluated the groundwater budget of the lower ACF, with particular emphasis on recharge, characterizing the spatial and temporal relation between surface water and groundwater, and groundwater pumping. To evaluate the hydrologic budget of the lower ACF River Basin, a groundwater-flow model, constructed using MODFLOW-2005, was developed for the Upper Floridan aquifer and overlying semiconfining unit for 2008-12. Model input included temporally and spatially variable specified recharge, estimated using a Precipitation-Runoff Modeling System (PRMS) model for the ACF River Basin, and pumping, partly estimated on the basis of measured agricultural pumping rates in Georgia. The model was calibrated to measured groundwater levels and base flows, which were estimated using hydrograph separation.The simulated groundwater-flow budget resulted in a small net cumulative loss of groundwater in storage during the study period. The model simulated a net loss in groundwater storage for all the subbasins as conditions became substantially drier from the beginning to the end of the study period. The model is limited by its conceptualization, the data used to represent and calibrate the model, and the mathematical representation of the system; therefore, any interpretations should be considered in light of these limitations. In spite of these limitations, the model provides insight regarding water availability in the lower ACF River Basin.

Correlating Groundwater Storage Change and Precipitation in Alabama, United States from 2000–2021 by Combining the Water Table Fluctuation Method and Statistical Analyses

“…Prior to 2008, the U. S. Geological Survey (USGS) employed various methodologies to explore changes in GWS within Alabama's aquifers. These methods included the utilization of groundwater flow models [19,20] and the application of geophysical techniques [21]. The computational expense associated with the modeling approach and the limited coverage of classical geophysical tools often precluded a comprehensive assessment of the entire state.…”

Ground-Penetrating Radar Detection of Hydrologic Connectivity in a Covered Karstic Setting

“…However, the effects of water demand and conservation are spatially heterogenous with some locations having a higher sensitivity to changes in water levels [11]. Thus, understanding which areas on the land surface are more closely linked to changes in groundwater levels will help optimize the numerical modeling that underlies policy decisions and resulting economic analyses [12,13].…”