The same problem is threatening the future of irrigated agriculture on the Texas High Plains and in part of eastern Washington’s Columbia Basin, but the proposed solutions are different.
Aquifers that supply water for irrigation and other uses are declining at alarming rates in both areas, and supplies will be short-lived without major changes.
Water conservation is the strategy on the High Plains, where water is pumped from the southern end of the Ogallala Aquifer. Once thought to be an inexhaustible water supply, the aquifer is dropping by up to 10’ per year in some parts of the region.
A number of water-saving farming practices have been adopted, and a state law will soon limit the amount of water each irrigator can use.
Rick Kellison, a Lockney, TX, farmer, says the expected restrictions for his area “will have a tremendous impact on some producers based on the amount of water they have available to pump and what their philosophy has been on using that water.”
Water conservation isn’t an option in the Columbia Basin Groundwater Management Area, says Paul Stoker of Othello, WA, its executive director. Roughly 250,000 acres are irrigated from deep wells in the four-county management area, and water levels are receding by up to several feet per year. The aquifers have no recharge and will go dry regardless of any conservation efforts, he says.
“Whether we conserve or not the water will be gone,” Stoker says. “We estimate that, in many of the areas here, we have about 10-12 years left.”
The best solution would be to expand a federal irrigation project to bring water from the Columbia River, an expensive proposition in today’s economy.
“There is water,” says Stoker. “But can we afford the pipelines to bring it here?”
When Hay & Forage Grower first covered the Texas High Plains situation three years ago, experts were predicting that the demand for water would exceed the available supply in 10-20 years.
The region, which encompasses most of northwestern Texas, including the panhandle, is said to be the largest area of contiguous agricultural production in the world. It leads the nation in cotton and fed cattle production, and in recent years has become a major dairy area, too.
But without water from the Ogallala, much of that production would be lost. After the problem was first identified in the 1970s, irrigators adopted more efficient irrigation methods. But as more and more wells were drilled, the water savings were erased and the drawdown resumed.
Research begun in 1997 revealed that farming systems that include forages, especially warm-season perennial grasses, can save significant amounts of water. More recently, as dairies moved into the region, studies found that forage sorghum can match the yield and quality of silage corn on 40-50% less water.
The research was coordinated by Vivien Allen, Texas Tech University forage agronomist, and verified in an extensive on-farm demonstration project directed by Kellison. Allen says many dairies have switched to forage sorghum, but some nutritionists still prefer corn silage.
In our earlier story, Allen predicted that the dairy expansion would have to end in order for the aquifer to be saved. Kellison says that essentially has happened, mostly because of low milk prices.
Five planned ethanol plants were another concern in 2008. Four have been built and three are operating, according to Kellison. Each of the two biggest plants produces 100 million gallons of ethanol per year from shipped-in corn, generating about 50 jobs.
“But at the same time for every gallon of ethanol being produced, they’re using about 2.3 gallons of fresh water,” he says.
The introduction of wind power is changing land use and may save water by reducing the amount of center-pivot irrigation, say Allen and Kellison. A lot of windmills are already in the region, and many more are expected.
“Change is in the wind out here, and change is absolutely necessary,” says Allen.
The biggest change will begin when the State Water Plan kicks in next year. It will include separate plans developed for 16 water regions in the state, including two that cover most of the High Plains. Mandated by a law passed in 1997, the plan is designed to address the state’s water needs for the next 50 years.
Already in place, the plan for Region A, which includes most of the panhandle, limits water users to 18” annually, Kellison reports. He farms in Region 0, which covers 20 counties and 6.8 million acres south of Region A and includes the city of Lubbock. A plan for that region, drafted by the High Plains Underground Water District, is currently in the public comment stage.
If approved, it will limit water users to 15” per year, a use level designed to leave the aquifer at 50% of its current level after 50 years. Farmers don’t like being told what they can and can’t do, and the biggest impact will be in areas where the aquifer presently is dropping by up to 4’ per year, says Kellison. Many irrigators in other areas won’t see much change, he adds.
“Our average rainfall is about 18.4”. If you add that to the 15” that you can apply through irrigation, that should be adequate water for an outstanding cotton crop and actually should get us to where we need to be on corn.”
Allen thinks more of the water will be used on crops that bring the highest return possible. She also expects to see more grazing because grasses need less water than row crops.
While the restriction should ensure adequate water until 2060, she’d rather see a longer-term approach. The Ogallala, says Allen, “is a virtually finite water resource. Fifty years from now – if we’re successful and 50% of what’s here now is here then – we’ll have very little water into the future.
“I don’t think there’s any less reason to be concerned about the water,” she adds. “I think there’s more reason to be concerned. The bright spot in this is that more people are aware that we have a problem, and that’s the first step in solving one.”
Groundwater levels are receding in all of eastern Washington, too, says Stoker. But his concern is for the deep basalt wells in the Columbia Basin Groundwater Management Area, which have been known to be receding for 20-25 years. He says the answer has always been to drill deeper, but in recent years deeper wells have yielded less water or the water was low in quality.
“We don’t have that option anymore,” says Stoker.
Because the wells are deep, the water is expensive, and irrigators already use it conservatively, he adds. Most have taken corn and hay out of their rotations and grow mostly small grains and grass seed.
The land could revert back to dryland farming when the wells go dry, but with less than 10” of annual rainfall in the area, some of it probably would sit idle instead. The other option is to divert water from the Columbia River when the river is high from snowmelt.
“If you can find a mechanism to store that winter runoff water, which no one has claim to, particularly, you can utilize it for human purposes, including agriculture,” he says.
About 700,000 acres in the management area already are irrigated with river water via the federal project, and adding the 250,000 acres now irrigated from wells would require relatively minor modifications. But a Bureau of Reclamation proposal for making those changes would be “extremely expensive,” says Stoker.
“So unless we can find a more economically acceptable mechanism to build the infrastructure, they’ll have difficulty replacing the groundwater with surface water,” he says. “That’s the simple challenge.”