A voluntary brush control program in progress on the North Concho River watershed could improve water yield of the river by 33,000 acre-feet per year, a five-fold increase.
Beneficiaries of the effort will include not only the ranchers and landowners participating in the project but also citizens and industries in San Angelo and nearby communities.
The North Concho feeds the O.C. Fisher Reservoir, at one time an abundant source of water for municipal and recreation use but now mostly a dried up lakebed holding only 6 percent of total water capacity.
The problem, in addition to a historic drought that has seared this West Texas area for the past five years or more, comes from the millions of mesquite and juniper trees growing in the North Concho river watershed.
"More than 130 million mesquite trees and more than 100 million junipers thrive in the watershed," says Johnny Oswald, project manager for Texas State Soil and Water Conservation Board.
Oswald says the trees' "tentacle roots act like straws to suck water from the watershed."
Selectively removing those trees will increase underground water resources for ranchers and farmers and divert more water into the North Concho and ultimately into the O.C. Fisher Reservoir.
In 1999, the Texas legislature, with strong support from State Representative Rob Junell of San Angelo, approved a two-year budget of $7-million for brush control in the watershed. That program began this year.
"A feasibility study indicated that removing brush would increase stream flow," Oswald said.
A computer model developed by the Texas Agricultural Experiment Station Blackland Research Center indicated the project could improve water flow significantly and economically.
Cost estimates show increasing stream flow through brush control would cost $53 per acre-foot of water. That compares to $160 per acre-foot that San Angelo currently pays for water from Lake Ivie.
"For citizens of San Angelo, the project means a less expensive source of water. That could translate to tax and water bill savings," Oswald says.
"The landowner benefits by getting increased gazing area and increasing the carrying capacity of the land," says Dandy Kothman, range conservationist with the Tom Green Soil and Water Conservation District.
"In areas with heavy brush, the grass gets shaded out," she says.
State money is used as cost-share to fund up to 70 percent of the projects. Landowners chip in 30 percent.
Oswald says brush control consists of both mechanical and chemical solutions.
"We had hoped to uses Remedy and Reclaim last summer," Oswald says. "But tree foliage was too sparse for effective herbicide treatments. We need at least 75 percent foliage and drought conditions reduced foliage to no more than 40 percent. We could not treat anything with herbicides this year. We hope to use chemical treatments next summer, depending on conditions."
Kothman says the window of opportunity to spray is narrow, June through August.
"Follow-up treatments are part of the cost-share equation," she says. "Land with light brush infestations are eligible for one follow-up within 10 years. Land with heavy infestations will be eligible for two follow-up treatments within 10 years after initial treatment."
Benefits may begin to accrue for landowners within a year after treatment as grasses become more competitive and stocking rates increase. "That depends on a more normal rainfall pattern," says Oswald.
Significant improvements in stream flow likely will not occur for about ten years.
Wildlife management is a significant aspect of every brush control plan, Oswald says. "We realize that hunting leases are an increasingly important aspect of a landowner's earning potential. Landowners have options about how much brush they want to remove but we average about 50 percent. They rely on recommendations from Texas A&M and Texas Wildlife to determine the best percentage of brush to leave."
Oswald said the program had paid funds to remove brush from 20,000 acres by September 2000. He hopes eventually to see up to 432,000 of the 950,000 acres in the North Concho River watershed treated through the program.
Eight other feasibility studies are currently underway across the state, Oswald says.