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The Lonoke The Lonoke Democrat Democrat
 
By: Ed Galucki, staff writer
Groundwater monitoring on prairie
Real-time monitoring of groundwater levels may not seem significant to some, but the effect could be far-reaching for the Grand Prairie area where water is the economic lifeblood. "This will help us get in black and white for people that there is a real threat to the aquifer," Dave Freiwald, hydrologist and assistant director of the U.S. Geological Survey (USGS) Arkansas Water Science Center, said.

Freiwald made his remarks during a press conference Monday unveiling the monitoring equipment installed on a well at the University of Arkansas Rice Research and Extension Center near Stuttgart. The real-time water levels are available on the USGS Web site, he said. While the research information is needed, perhaps the greatest significance of the monitoring is its importance to education. A USGS report released last year warns that unless steps are taken to change groundwater demands, irreversible damage to the alluvial aquifer could occur within seven to 10 years.

Arkansas is the fourth largest user of ground water in the United States; much of this water is removed from the Mississippi River Valley alluvial aquifer in eastern Arkansas, Freiwald said. An average of about 11 billion gallons of groundwater is pumped each day, he said.

Agriculture, mainly for irrigation, draws about 72 percent of that total, Freiwald said. In the state, Arkansas County is the largest user of ground water for irrigation, using over 600 million gallons per day. Other counties . rice-producing areas, such as Lonoke and Prairie counties, are not far behind, he said.

An aquifer is a layer of porous materials, such as sand and gravel, that allows the movement of water through it. Much of the Grand Prairie is above several aquifers but the primary water sources are the alluvial and Sparta aquifers. Other aquifers are too small, too deep or tainted with salt.

Long-term measurements, often over more than 60 years, have shown an average decline of more than 1 foot a year in some areas, Freiwald said. "We are using the ground water faster than it is being replaced," he said.

The real-time monitoring will allow the declines from seasonal pumping to be tracked more accurately, Freiwald said. There used to be a lag time of up to three months in compiling well data, he said. Decline of the water level in the alluvial aquifer has been documented since the late 1920s, but was noticed as early as the 1900s after the introduction of rice cultivation to the Grand Prairie. Since then a "cone of depression," an area depleted of groundwater, has formed in the alluvial aquifer underlying Lonoke, Prairie, Monroe and Arkansas counties.

"We have seen declines of nearly 70 feet in some wells," Freiwald said. A report, based on a recent ground-water usage model, has predicted about 400 square miles of the aquifer will go dry by 2049," said Freiwald. "This series of Web pages helps us provide water-level information to a wider audience than we typically reach with our published USGS reports," Freiwald continued.

Traditionally, agricultural demands have drawn on the alluvial aquifer leaving the deeper, higher quality water of the Sparta for use by municipalities. However, demands on the alluvial aquifer have outpaced its ability to recharge, or replace the water, forcing farmers to tap the Sparta aquifer.

One of the functions to be met by the Bayou Meto Water Project will be to deliver irrigation water from the Arkansas River to area farms through existing stream beds and dug canals. The project would serve land in Lonoke, Prairie and Arkansas counties. Other functions of the project are wetland reclamation, flood control, and wildlife management.

Randy Young, director of the Arkansas Soil and Water Conservation Commission (ASWCC), said he used a wireless Internet uplink while on his way to the press conference to check the well.

The ASWCC in 1998 declared several counties in eastern Arkansas, including Lonoke, as "Critical Ground Water Areas" because of rapid and sustained water level declines. "The real-time data will be an excellent awareness and educational tool, and a key part of the State.s overall conservation efforts," Young said. "We expect to even see this used in classrooms," he remarked.

Ground-water level data can be viewed on the internet at the USGS Web site http://ar.water.usgs.gov/
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