Mississippi, Arkansas, and Tennessee Regional Aquifer Study

Ground-water resources in the Memphis area, Shelby County, Tennessee and the surrounding counties in Tennessee, Mississippi and Arkansas are critical to meet the growing water-use demands for public-water supply, industrial use, and irrigation.

Partner Programs and Agencies

Partner Investigations

Office of Ground-Water Ground-Water Resources Program

Ground-Water Basics

Ground-Water Institute

Mississippi Embayment NAWQA

USGS Science Centers

Mississippi

Arkansas

Tennessee

Earthquake Hazards

State and Local Agencies

Tennessee Department of Environment and Conservation

Mississippi Department of Environmental Quality

Arkansas Natural Resources Commission (formerly Soil and Water Conservation Commission)

The U.S. Geological Survey (USGS), the University of Memphis - Ground Water Institute (GWI) in conjunction with partner universities in the area, and the City of Memphis and Shelby County, Tennessee have resumed work on a study of the geologic framework and ground-water flow in the Mississippi embayment and surficial aquifer systems in the Mississippi embayment in federal fiscal year (FY) 2006. Known as the Mississippi, Arkansas, Tennessee Regional Aquifer Study (MATRAS), the study initially began in 1999 with the objective of improving definition of the hydrogeology and ground-water flow in the Tertiary aquifer system in the Memphis area of northwest Mississippi, east-central Arkansas, and southwest Tennessee.

In developing a general framework for the MATRAS study, the GWI and Shelby County, Tennessee have re-defined the overall objective as "…a much improved understanding of the water resources and availability in the Mississippi embayment to the degree that interested parties can develop the policies and programs necessary to ensure a sustainable regional ground water supply that will suffice for future municipal, industrial, agricultural, and environmental needs." (GWI, White Paper to U.S. Congress, 2005, written comm.). Today, MATRAS comprises an overarching partnership for studying the ground-water resources in the Mississippi embayment and surficial aquifer systems in an approximately 170,000 square mile (mi2) area of the Mississippi embayment under which a set of specific initiatives will be carried out by the various project participants in mutual support of the goals of MATRAS.

Currently, there are three ongoing initiatives within MATRAS. These consist of:

1) the Mississippi Embayment Regional Aquifer Study (MERAS), a 3-year initiative begun in FY2006 and lead by the USGS Arkansas Water Science Center (WSC), with assistance by the Tennessee, Mississippi, and Louisiana WSCs, and funded by the USGS Ground-Water Resources Program (GWRP). The primary objectives of MERAS are to:

• enhance understanding of regional ground-water flow and aquifer storage in the Mississippi River Valley alluvial and Mississippi embayment aquifer systems,
• estimate water-budget components for the ground-water flow system in areas dominated by irrigated agriculture or public-supply withdrawals,
• evaluate the existing water-level monitoring and recommend improvements in monitoring network design and understanding of hydrologic factors crucial to the assessment of ground-water availability, and
• assess the ground-water availability of the aquifer systems;

2) the Mississippi Embayment Regional Ground Water Study (MERGWS), a proposed 5-year initiative begun in FY2006 and lead by the GWI, with participation by the University of Mississippi and Arkansas State University; local support by the City of Memphis, and Shelby County, Tennessee; and collaboration by the USGS Mississippi, Arkansas, and Tennessee WSCs. MERGWS currently (2006) is funded for one year under a federal earmark through the U.S. Environmental Protection Agency (USEPA). The primary objectives of MERGWS are to:

• sharpen the understanding of the physical and chemical states and processes within the regional ground-water system,
• assess the current data collection infrastructure and requirements for supplemental and new data, and
• establish a Science Advisory Committee;

3) the MATRAS Sub-Regional Model (MATRAS-SRM). Work on MATRAS-SRM resumed in FY2006 under the lead of the USGS Tennessee WSC, with assistance by the Mississippi and Arkansas WSCs, and the GWI and its partners. MATRAS-SRM currently (2006) is funded under a one-year federal earmark complimentary to MERGWS through the USGS. Similar in scope to the flow-modeling component of the original 1999 MATRAS, the primary objectives of MATRAS-SRM are to:

• define the geologic and hydrologic framework of the Mississippi embayment and surficial aquifer systems in the MATRAS area and assist in development of the regional ground-water flow model under MERAS,
• define the current hydrologic stresses on and hydraulic characteristics of the aquifer systems, with emphasis on the major Tertiary public-supply aquifers, including improving understanding of recharge rates,
• ground-water/surface-water interaction, aquifer properties, and ground-water withdrawal locations and rates, and
• use the MERAS regional flow model to develop a sub-regional flow model of these aquifers in the Memphis area to simulate local changes in ground-water withdrawals and flow.

Potentiometric Surfaces for the Memphis Aquifer, 1886 - 1995

Water-Use Comparison 1985 - 2000

Inventory of Geophysical logs, Shelby County (2000)

Click here to access the interactive map for the MATRAS area.

Web page by George E. Peters, Michael W. Bradley, and John K. Carmichael 2006