Wednesday, April 2, 2008 : 2:20 p.m.

Ground Water Resources in The Memphis Area, Tennessee, Mississippi, and Arkansas – The Impact from Development and Increased Use

Michael W. Bradley and John K. Carmichael, U.S. Geological Survey

Ground water is the primary source for public, industrial, and agricultural supplies in the northern Mississippi embayment.  Withdrawals from the Memphis/Sparta and Fort Pillow aquifers, mainly the Memphis aquifer, have lowered the potentiometric surfaces of these aquifers throughout the area.  In the Memphis, Tennessee area, the potentiometric surface of the Memphis aquifer has declined by as much as 125 feet since about 1886.  The cone of depression extends into eastern Arkansas and northwestern Mississippi.  The Mississippi River alluvial aquifer is a major source of water for irrigation in eastern Arkansas and northwest Mississippi. 

Ground-water withdrawals for public supply from the Memphis/Sparta and Fort Pillow aquifers in the area increased from 186 million gallons per day (Mgal/d) in 1985 to 230 Mgal/day in 2000. Most of the withdrawals, 187 Mgal/d, occurred in the Memphis, Tennessee area.  Ground-water withdrawals from the Mississippi River Valley alluvial aquifer for irrigation are significantly higher than the total amount of water withdrawn from the Memphis and Fort Pillow aquifers.  Ground-water withdrawals for irrigation from the alluvial aquifer increased from 1,170 Mgal/day in 1985 to about 2,800 Mgal/day in 2000

Development of the Memphis/Sparta aquifer of and the alluvial aquifer in the three-state area is expected to continue.  The increase in ground-water demands will result in additional lowering of the potentiometric surfaces, changes in ground-water flow directions, changes in recharge, and possibly changes in water quality. The possible effects on the increasing production from the Mississippi River Valley alluvial aquifer that overlies the Memphis/Sparta aquifer are only beginning to be defined for the northern Mississippi, eastern Arkansas, and western Tennessee area.  Declining water levels in the alluvial aquifer, particularly in eastern Arkansas, may affect recharge through the alluvial aquifer to the underlying Memphis/Sparta aquifer, as well as surface-water resources in the area. 

Michael W. Bradley, U.S. Geological Survey Ground-water hydrologist with the USGS. Assistent Director for ground-water studies in the Tennessee WSC. Professional geologist. Adjunct faculty - Tennessee State University

John K. Carmichael, U.S. Geological Survey Jack Carmichael is the Ground-Water Specialist for the Tennessee Water Science Center, U.S. Geological Survey. Jack has been with the USGS for more than 25 years in the Memphis and Nashville offices. Jack is also a registered geologist and is the USGS project chief for the ongoing ground-water investigations of the Memphis aquifer in the Memphis area.


2008 Ground Water Summit