To say that Gary Esslinger’s erosion control problem is wide spread is an understatement. He maintains a complex irrigation system, with hundreds of miles of earthen ditches and canals, that is designed to get water from the Rio Grande River to thousands of farmers.

Esslinger is maintenance chief for the Elephant Butte Irrigation District, a part of the New Mexico portion of the Rio Grande Project, which furnishes irrigation water for about 200,000 acres of land, and electrical power for communities and industries in south-central New Mexico and west Texas.

The project included two large storage dams, six smaller diversion dams, 139 miles of canal, 457 miles of irrigation laterals off the main canals, 465 miles of drains and a hydroelectric power plant. It helps irrigate approximately 5,000 farms, and provides municipal water service for about 450,000 people.

?EUR??,,????'??The part of the project I maintain consists of 327 miles of canals and laterals, and 200 miles of drains,” Esslinger said.

?EUR??,,????'??The system is old. The major dams and canals were constructed in the early 1900’s. Most of the laterals and ditches were built in the 1920’s. Almost the entire system consists of earthen channel, laterals and ditches. We are continually rebuilding eroded sections. During the, summer of 1986 we rebuilt 14 areas. In each case, we had to bring in between 2,000 and 6,000 cubic yards of dirt. We currently have 96 more areas where we anticipate doing erosion control work this winter.”

Esslinger has turned to an erosion control product called Armater, which was recently introduced in the United States by Geomatrix Systems, a division of Akzo, in hopes of alleviating his problem.

“I was searching for a cost effective method of dealing with erosion,” Esslinger said. “The cost of lining hundreds of miles of canals with concrete was prohibitive. I approached a local distributor who deals in erosion control products, and he sold me on the merits of trying Armater. I understand this is the first application of the product in the United States.”

Armater is a three-dimensional, semi-rigid geomatrix made of non-woven, polyester fabric. It is permeable, light weight and rot-proof, and provides virtually permanent erosion control.

The hexagons that make up Armater’s honeycomb design are four inches deep and have eight-inch sides. After it has been placed on a surface, it can be filled with native soils, sand, gravel, pea gravel or other aggregate. Surface water flow is impeded and slowed by the raised edges of the hexagons.

The Rio Grande Project has thousands of control gates, which are used to hold water and then release it as necessary for irrigation. Water used for winter power generation is released from a dam near Truth or Consequences, New Mexico, held in a reservoir 25 miles downstream and eventually released for irrigation use during the summer. The control gates used in the irrigation system are supported by concrete structures.

During the summer growing season, the water is continually rising behind the control gates and being released,” Esslinger noted. “The water drops rapidly as it rushes out of the concrete control gates and when it hits the earthen canals and laterals it causes erosion, Our situation is not unlike what you have on an ocean beach, with the continuous rise and fall of the tide.”

Esslinger tried Armater in 1986 in one of the laterals where he was having erosion problems.

“We installed several hundred square feet in January 1986, when the system was drained because the growing season was over,” Esslinger recalled. “The Armater was spread was spread out and anchored across a two to four foot flat ledge and down the slope. All that’s needed to join a series of panels is a commercial stapler.

“We filled the honeycombs in the Armater with a mixture of rock fine, consisting of baseball to football size rocks, and soil to keep the banks stable. The Armater was installed quickly and with a minimum of labor. It is inexpensive when compared to the alternatives of installing concrete or riprap.”

About two weeks after the Armater was installed, the system was filled with water again for the growing season. The Armater was underwater for about nine months until the water was drained for the winter in mid-October.

?EUR??,,????'??The Armater seemed to perform well while it was under water,” Esslinger said.
?EUR??,,????'??When we drained the system the Armater looked just like when we put it down. It was not stretched out or deformed. There was even some Bermuda Grass growing on the slope, which indicates the Armater anchored everything down like it is supposed to do.

“Overall, I was pleased with the results. There was only one small area where we had a minor problem, and that was caused because we weren’t as careful as we might have been in achoring the Armater when it was installed it.”

When unfolded, each Armater panel is 33×66 feet and covers an area of about 240 square yards. Esslinger installed additional panels in four different locations this year to see how it would perform under a variety of conditions. He intends to conduct a thorough inspection of the results when the irrigation system is drained for the winter.

“We have installed a total of six panels, he noted, “and in only one area did we have a problem. We tried it in a section where the water had washed away a section of concrete. There was so much turbulence and water velocity that it first washed out the dirt in the Armater. The rock and other fill material was put under such stress that it put a severe strain on the fabric and started to tear it away.

The water in that area had a velocity of between 500 to 600 cubic feet per second (CFS).

“We tried it in another area that had a flow rate that averages 200 CFS,” Esslinger said. “We have had no problem there. The Armater seems to be totally unaffected by the water flow, and five of the six panels we have installed are performing successfully.

?EUR??,,????'??I think Armater performs best where flow rates are 300 CFS or less. Our tests seem to indicate the product may reach its limits in conditions where the water flow is over 400 CFS.”

Esslinger plans to install additional panels of the erosion control product this winter.

“I forsee the day when most of our areas which are susceptible to erosion are covered with Armater,” he said.

Geomatrix Systems holds the distribution rights for Armater in the United State. The product is widely known and has been successfully used in Europe for about 11 years. In 1983, Armater received the “Prix Innovation” award from the Union of Public Works Professionals in France.