State Water Resources Research Institute Program
Project ID: 2007MS63B
Title: Climatological and Cultural Influences on Annual Groundwater Decline in the Mississippi Delta Shallow Alluvial Aquifer: Identifying the Causes and Solutions
Project Type: Research
Start Date: 3/01/2007
End Date: 2/29/2008
Congressional District: 3rd
Focus Categories: Climatological Processes, Groundwater, Water Use
Keywords: Delta alluvial aquifer; recharge; withdrawal; catfish; rice; climatic variability
Principal Investigators: Wax, Charles; Massey, Joseph H.; Pote, Jonathan
Federal Funds: $ 19,602
Non-Federal Matching Funds: $ 95,528
Abstract: The shallow alluvial aquifer is the main source of groundwater developed in the Mississippi Delta region. The aquifer is heavily used for irrigation of corn, soybeans, and cotton, as well as for rice flooding and filling aquaculture ponds in the prominent catfish industry. Water levels in the aquifer are subject to seasonal declines and annual fluctuations caused by both climatological and crop water use variations from year-to-year. These declines can be dramatic and are most notable during the period April-October of each year, particularly in years when normal crop water demands are accentuated by concurrent abnormally dry climatic conditions. Recharge during the remainder of the year has recently been insufficient to restore water levels, and the aquifer is now being mined at the approximate rate of 300,000 acre-feet per year. To underscore the critical nature of this water problem, the most recent water level decline in the aquifer (October 2005- 2006) is estimated at 500,000 acre-feet (Pennington, 2006). This may represent a worst-case situation in which severe drought combined with consequent increased demand for irrigation. It is estimated that water use for row crops doubled during this period (Pennington, 2006).
It is of critical importance to understand how climatological variability and cultural uses of the water cause the groundwater level in the aquifer to vary. It is also critical to discover and implement management strategies to use precipitation and other surface water sources as substitutes for aquifer withdrawals and thereby reduce the use of groundwater in the region. Stopping the consistent drop in water level in the aquifer will require a curtailment of about 300,000 acre-feet of groundwater use each year, and this is the highest priority of this research project. This information is essential to agricultural producers in the region and to planners in the Yazoo Water Management District who must design sustainable water use scenarios which will allow continuation of the productivity of the region.
Progress/Completion Report, PDF