Moisture sensor photo PAUL RODRIGUE/NRCS
Soil moisture sensors are among the many irrigation technology developments helping Delta farmers conserve water.

Delta water conservation measures aided by NRCS programs, cost-share

New irrigation technology, especially telemetry, is making old practices more acceptable, accurate, and usable

“Those who cannot remember the past are condemned to repeat it.” — George Santayana
 
This quote by the Spanish philosopher has been paraphrased in many forms, says Paul Rodrigue, USDA Natural Resources Conservation Service, “but the underlying message applies even today to the conservation/groundwater issue that has been a concern for Mississippi Delta agriculture for many years, concurrent with the widespread adoption of irrigation for crop production. “

Now that successive generations of the region’s farming community have dealt with the Delta water issue, a historical review — beginning with the work of the Soil Conservation Service, which evolved into the Natural Resources Conservation Service — can provide perspective for today’s producers, he said at a recent water seminar for the Agricultural and Biological Engineering Department at Mississippi State University.

Rodrigue, who is supervisory engineer for the USDA/NRCS Area 4 Engineering Office at Grenada, Miss., says that beginning in the 1980s the growth of irrigation/groundwater use in the Delta initiated several activities. “Primary among these was aquifer modeling activities by the U.S. Geological Society (USGS). After running various demand scenarios, sustainability of the aquifer was a concern. In 1987, there were approximately 3,000 permitted wells in the Delta — today that number is approximately 20,000.”

Due in part to those concerns NRCS, under the leadership of then State Conservationist Gene Sullivan, established an irrigation team in 1985 to assist in determining the best water conservation practices for the Delta. Sullivan’s experiences with water issues in Arkansas was a useful resource in helping NRCS Mississippi be proactive in water issues in the Delta, says Rodrigue, who during his NRCS career has been a witness to most of the conservation-related programs and projects.
 
EXTENSIVE IRRIGATION STUDIES
“Between 1986 and 1992, the irrigation team conducted studies and made many evaluations of systems and practices, including center pivot irrigation, pumping plants, furrow irrigation, rice evaluations, irrigation scheduling, soil infiltration, the 6/3 method for aquaculture developed by Drs. Jonathan Pote and Charles Wax at Mississippi State University, permanent pads (a conservation practice developed with the then Agricultural Stabilization and Conservation Service), flowmeters, side/multiple inlets (e.g., rainfall harvesting in rice, similar to the 6/3 method), and winter-flooding for wildlife.

“I remember doing irrigation scheduling work on the farm of the late Robroy Fisher, Washington County farmer, who was implementing the GOSSYM/COMAX cotton model, including the installation of an on-farm weather station. His use of COMAX included following the COMAX irrigation scheduling routine —another example of what is old becoming new again.”

Since 1992, especially with the formation of the YMD Water Management District, Rodrigue says, NRCS terminated its evaluation work and has focused on implementing conservation practices in cooperation with Delta farmers to address the water supply issues. Financial assistance is made available to assist with the adoption of water conservation measures, especially with “new” practices.

“One of our challenges,” he says, “is trying to keep up with changing practices and technologies, especially with the computer and electronics evolution. It takes about 18 months to introduce something new into our suite of conservation practices and financial assistance programs in order to make it available to our cooperators. The focus lately has been on automation and communication. Farmers need the ability to remotely monitor and control irrigation systems to obtain the greatest water conservation benefit.”
 
TECHNOLOGY TIME SAVINGS
New technology, especially telemetry, is making old practices more acceptable, accurate, and usable, Rodrigue says. “A farmer in the 1980s, or now, often doesn’t have the time to go out and manually read soil moisture sensors, but having the ability to check multiple sensors on a smart phone or other electronic device, while compiling a season-long record of that device, makes the information more accessible and usable. Implementing the 6/3 method, or rainfall harvesting, in rice required manual observations on site — now, with pressure transducers and telemetry, management can be done remotely and instantaneously.”

Noting that the first known irrigation took place in 6000 B.C, the first water lifting occurred in 1700 B.C., and the first water pump, the ox-powered Persian water wheel, was employed in 500 B.C., today, he says, “we have internal combustion engines and various forms of pumps. Electric motors now have variable-frequency drive allowing for flow rate control.

“The first surge/cutback irrigation was done by releasing water from surface water conveyances to fields and furrows though multiple openings at first (siphon tubes in the mid-1900s), then eliminating openings until only one maintenance flow opening remained. In the 1980s, the first surge valves came to the Delta, with little acceptance. Now, with more sophisticated technology (electronics, solar panels, batteries), there has been a rediscovery of the cutback scheme using modern surge valves. And the introduction of poly-pipe has made almost the entire Delta irrigatable.”
 
WATERSHED PLANNING PROJECT
After the NRCS Irrigation Team was dissolved, the agency conducted a watershed planning project with the Yazoo Mississippi Delta Water Management District that resulted in the Delta Water Supply Study that addresses three areas: conservation, surface water importation, and low flow augmentation of the Sunflower River. “This study remains the template for water supply issues in the Delta,” Rodrigue says.

NRCS groundwater modeling, as part of the water supply study, indicated that the equivalent of approximately 250 wells in the central Delta needed to be removed from groundwater, based upon the model parameters of 1992 (example, fewer well permits). The groundwater reduction could be realized, the study said, through conservation, tailwater recovery, on-farm storage, increased surface water utilization, and importation to make more water available. “A modern twist,” he says, “is the possible transfer of groundwater-to-groundwater, now being studied by several agencies. Surface water importation was part of the study, and was based on the 1979 Corps of Engineers-funded study, Flow Augmentation of Deer Creek.” “This is a topic that remains valid today,”

Rodrigue says. “The first project completed by Yazoo Mississippi Delta as part of the study was the YMD well field to provide the Sunflower River augmentation, a project that continues to this day, as needed. “The water supply study focused on using the Mississippi River as the primary source of water; however, several sources and forms of water Importation and transfer continue to be studied by the various agencies in the Delta.

“My first experience with the discussion of water importation from the Mississippi River occurred while I was a graduate student at Texas A&M, and concerned the possible importation of water from the river to the High Plains of Texas as part of the 1968 Texas Water Plan. Aqueducts for inter-basin water transfers date back to 900 B.C, and possibly further. Large water conveyance systems have existed in the western and mid-western U.S. since the 1850s.”
 
IMPORTANCE OF DRAINAGE
For any surface water importation project, Rodrigue says, “The Delta will have to answer a central question, since the first, second, and third word on any Delta farmer’s mind is Drainage! Drainage! Drainage! Should a supply system use existing surface water bodies, managed for dual purpose, or be a completely separate system (example, an aqueduct)? Again, this is an example of how modern technology makes something feasible today (example, a dual-purpose system), that probably wasn’t feasible just 20 years ago. Groundwater-to-groundwater importation would necessitate the use of a pipeline.”

Since 1996, the year the Environmental Quality Incentives Program (EQIP) began), Rodrigue says the NRCS’ principal role in the Delta water supply issue been to ensure that technical (survey and design) and financial assistance is available for water conservation and supply practices. “The Delta Conservation Partnership has done an excellent job of ensuring that NRCS conservation programs are funded appropriately in the Delta. Since 1996, approximately $336 million in financial assistance, matched by farmers, has been utilized in the Delta to address various conservation issues, including water conservation.”

In 2014, the Mississippi Water Conservation Management Project (MWCMP) received funding targeted for water conservation measures. From 2014 through 2017 a total of $17 million in financial assistance, matched by farmers, was obligated, resulting in over 4,400 conservation practices.
 
VOLUNTARY METERING PROGRAM
Among the accomplishments of the MWCMP was the installation of over 1,000 flowmeters, which have assisted in meeting the Delta Voluntary Metering Program goal of metering and reporting water use on 10 percent of the Delta’s groundwater wells. The MWCMP has also assisted in the renovation of nearly 200 center pivot sprinkler systems being renovated with drop nozzles and new nozzle packages.

PAUL RODRIGUE/NRCSRodrigue chart

 “In Fiscal Year 2018,” Rodrigue says, “NRCS offered the Farm Production and Conservation (FPAC) Irrigation Water Quantity Project. These funds were used to promote increased use of available surface water in the Delta. Overall, in FY18, NRCS provided over $13.4 million in financial assistance for cooperators to match to install water conservation practices across the Delta. NRCS is expecting the same level of funding, if not more, in fiscal 2019, so farmers should be sure they have an application on file with their local NRCS office for participation in FY2019 programs.”

Over the last 30 years, Rodrigue notes, Delta farmers have addressed the groundwater issue by installing various water conservation measures, adopting new technologies, and planning for the future. “But challenges remain, and additional water conservation goals are still to be met. NRCS has been proud to be an active participant with our Delta farmers and conservation partners in addressing the Delta’s groundwater issues for more than three decades, and we look forward to being a conservation partner in the Delta for another 30 years, with new employees, new cooperators, new technologies, and new generations of farmers.”

TAGS: Conservation
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