This annual Water Resources Conference is hosted by Mississippi State University’s Water Resources Research Institute and provides one of the main ways to keep up with groundwater and surface water issues in the state. It was held at the Jackson Hilton Hotel April 11-12.
Much of the conference’s emphasis was on consumptive groundwater use in the state’s “Delta” region - the center of large scale row-crop commodity agriculture. The Mississippi Alluvial Plain (MAP) aquifer irrigates corn, soybeans and cotton and fills catfish ponds in a cluster of counties in the central Delta. Under this region, a cone of depression and lowered water table exist caused by wide-scale pumping and comparatively slow groundwater recharge. Several United States Geological Survey scientists addressed this problem. Ideas set forth to solve overuse of the aquifer include irrigation efficiency, tail-water recovery and on-farm surface storage, constructing weirs (short dams) on local streams to create impoundments, inter-basin transfers of water between the Tallahatchie and Quiver River Basins, and the abstraction/ injection scenario of pumping surface water back down into the aquifer to replenish it.
Injection was most expensive but was the only method aggressive enough to raise the level of ground water in the aquifer and make net gains over 50 years. Building weirs to impound sections of streams was the least expensive in terms of energy and equipment inputs.
One talk covered the work of the MDEQ dam safety program. Mississippi has 5692 inventoried dams around the state of which 306 are high hazard dams that can affect human life and property if they fail. In 2016 one dam failed, and there were 8 “incidents” that required quick action to avoid failure.
Mississippi Department of Environmental Quality staff gave updates on BP Restoration projects that it manages. Alina Young of MDEQ’s Office of Restoration covered a Lower Pearl River Flow Modeling project that will run for 3 years and characterize hydrodynamics and water quality through studies that concentrate on the lower 65 kilometers of the Pearl River – basically the reach of the Pearl downstream of the diversion at Walkiah Bluff. This modeling is needed to support the $50 million shoreline and oyster bottom restoration just east of the mouth of the Pearl River. Allen Engineering of Ridgeland will create the models. This investment in modeling to support restoration is important and underscores our lack of knowledge about the Pearl River. Building more dams on it in Jackson like the proposed “One Lake” project will likely complicate the flow characteristics that this modeling seeks to clarify.
A graduate student from Mississippi State won an award with his presentation on the contribution of Oxbow Lakes in the Delta to the recharge of the Mississippi Alluvial Aquifer, and USGS staff scientists from Nashville compared methods to best measure evapo-transpiration in the Mississippi Alluvial Plain region. A scientist from the USDA Soil and Sedimentation Lab in Oxford covered recent precipitation trends in the middle and lower Delta, revealing an increase in these events in the lower Delta. There’s been a 27% increase in intense precipitation events in the Southeast in the last decade. This presentation also emphasized that water conservation practices to reduce sediment and nutrients in waterways become increasingly important in a changing climate.
Even the social sciences were represented at the conference by cooperative extension service researchers who examine the “human dimensions” of transferring nutrient and soil science research to the farmers who put it into practice. Farmers from Minnesota down to Louisiana are being asked to reduce nutrient over-enrichment in the Mississippi River Basin that worsens the Gulf of Mexico dead zone. It was good to learn that there are interstate groups of talented university extension staff, throughout the Mississippi River Basin, collaborating to address nutrient and Gulf hypoxia issues.
Mississippi State’s Sandra Guzman spoke about collaborating with social scientists at the University of Wisconsin and elsewhere in the Basin to generate social indicators to describe the skills, knowledge, awareness, beliefs and values that farmers employ in their understanding of how their on- farm nutrient management practices mesh into overall nutrient reduction strategies imposed by states. The individual farmer was described as the “black box” in the nutrient reduction equation and this university research on social indicators is meant to facilitate surveys that help them figure out what’s in that box.
The conference presentations addressed the most pressing challenges in water management in Mississippi and offered a sampling of research on ground and surface water issues across academic disciplines.
Andrew Whitehurst is GRN's Water Program Director.