An Alternative Water Source and Recovery of the Sparta Aquifer in South Arkansas

In 1996 the Arkansas Natural Resources Commission designated Bradley, Calhoun, Columbia, Ouachita, and Union Counties in southern Arkansas as a "Critical Ground Water Area" for the Sparta aquifer. In Union County water levels had declined greater than 360 feet since the 1920's. Groundwater flow models developed by the U.S. Geological Survey (USGS) indicated that water levels could be maintained by reducing Sparta aquifer withdrawals in Union County by 72 percent of the 1997 rates.

In 1999 the formation of the Union County Water Conservation Board (UCWCB) resulted in the Ouachita River Alternative Water Supply Project to withdraw water from the Ouachita River for use in Union County. Conservation and reuse of water (initiated in 2000) and conversion to a surface-water source for three industrial users (2004-2005) have reversed the trend of declining water levels in the Sparta aquifer. In 2002, the UCWCB in partnership with the USGS and Burns & McDonnell initiated a study to monitor the Sparta aquifer.

Eight real-time water-level wells and 12 water-quality wells are monitored in southern Arkansas and northern Louisiana. Additionally, the Union County Conservation District maintains eight continuous recorder water-level wells. Biannual water levels are measured by the USGS in over 90 wells in the five counties. Water-quality samples are collected semi-annually in the 12 wells.

 In the cone of depression in Union County water levels have recovered about 90 feet since 1999.  In over 20 wells, an average rise in water level of 5 to 15 feet per year has occurred from 2005 to 2009. In 2001 the water level in the cone of depression was about 170 feet below the top of the aquifer and had risen to 80 feet below the top of the aquifer by 2009. Water-quality monitoring shows no change in water quality with rising water levels.