Saving the Ogallala: How to Reverse Its Decline
A number of efforts are underway to help save water in the Ogallala Aquifer for future generations. Conservation is critical, but artificially recharging such an aquifer, even though it has to overcome sizeable hurdles, is a must.
By Richard Banks
<< See the story from FarmLife: “A Sinking Feeling: Saving the Ogallala”
First, to recharge an aquifer, one needs surplus water. Western Kansas, which was once considered part of the “Great American Desert” and where, accordingly, the aquifer’s decline is most severe, runs dry most years. Yet, studies are underway to help natural forces replenish the Ogallala, itself part of the High Plains Aquifer.
First, consider it would take anywhere from 5,000 to 10,000 years for nature to run its course and replenish the Ogallala, according to Andrew Ziegler, director of the United States Geological Survey Kansas Water Science Center. Now, take into account that 40% of the aquifer has been depleted through pumping, mainly for agricultural irrigation since the end of World War II. In some areas of western Kansas, the Ogallala is already reportedly too low to pump.
Nascent Technology Shows Promise: Equus Beds
Because of the relative speed of that drawdown, alarm bells have sounded, leading officials in Kansas, as well as others in the High Plains, to study and develop various methods to artificially recharge groundwater sources. One project currently underway is in central part of the state, where the City of Wichita has been recharging the Equus Beds aquifer, the easternmost portion of the High Plains aquifer in Kansas.
Underway since 2007, phase 2 of the project was completed in 2013. The amount of water artificially recharged into the aquifer has totaled, as of July 2016, about 8,600 acre-feet, according to Scott Macey, City of Wichita water resource engineer. That total, according to figures from Macey, is about 15% of the total Wichita draws in a year, cumulatively, from the aquifer as well as a local reservoir.
“Recent weather has allowed the Phase 2 facility to achieve its target performance,” Macey writes in a recent email to FarmLife. However, he continues, “River flows and water quality conditions in the years 2013-2015 have limited the number of days the [aquifer storage and recovery] ASR plant operated.
“When runoff occurs, the water sometimes contains contaminants that are undesirable for recharge to the aquifer. When the contaminant levels exceed the treatment plant’s ability to remove them, the water should not be taken from the river.”
According to Mandy Stone, project chief for Equus study, U.S. Geological Survey (USGS), Kansas Water Science Center, the project’s planners have successfully monitored the recharge project’s effect on water quality. “Studies have shown minimal effects of artificial recharge on Equus Beds aquifer water quality and indicate some benefits from recharge efforts, such as increasing water levels in parts of the aquifer,” says Stone. She notes that recharge efforts have slowed the encroachment of or diluted the presence of pollutants coming from such activities as oil production and fertilization of farms and lawns.
Looking ahead, Macey writes, “It is anticipated that 2016 rainfall patterns and river conditions will allow the ASR plant to exceed its previous days of production” and increase recharge efforts.
Already says Ziegler, the recharge project has had an effect on reversing previous declines in the aquifer. “By decreasing the proportion of water Wichita pumps from the Equus Beds aquifer, [along with] natural and artificial recharge, storage in the aquifer has recovered 50% since the all-time low in 1993.”
“Aquifer recharge can be a viable strategy in Kansas under the right conditions,” adds Macey. “ASR remains an important component of Wichita’s water supply portfolio and is critical for future drought resiliency.
“Work is being done to optimize the current facilities and to determine how future enhancements fit into the city’s phased in approach to water supply,” Macey continues. “The overall effectiveness of the project may ultimately be determined by the level of cooperative participation by Equus Beds stakeholders.”
Western Kansas: No Water, No Recharge
In western Kansas, where aquifer depletion is among the most severe, recharge efforts are virtually non-existent, in large part because there’s little excess water to be used for such a project. Plans, however, are in the works to at least better study the potential. Especially in recent years, state officials, farmers and others have wanted to explore the possibilities of “harvesting” excess rainfall and using that to replenish groundwater (which, by the way, is another term for water stored underground by natural and artificial means).
“We want to be able to capture high-flow events and keep that surplus water in the state to use,” says Tracy Streeter, director of the Kansas Water Office. “That’s really the premise for securing additional water supply for Kansas—to grab that surplus water where we have it and then keep it here.
“Whether we store it in a reservoir or pursue a large transfer, we haven’t looked at the details yet of storing excess flows or interconnectivity between reservoirs,” explains Streeter. “But how do you secure that water legally? So, there’s some talk about looking at different options to doing that. But beyond that, the state of Kansas hasn’t made a move with the next step.”
Streeter does, however, point to a proposed private-sector project in Garden City, Kansas, where the Dairy Farmers of America are constructing a processing facility. As a byproduct of producing whole, skim and nonfat dry milk powder, the plant will, according to Streeter, generate approximately 1 million gallons of wastewater per day.
“The majority of the water is going to go to Garden City, and they’re going to be looking at all kinds of different options for that. Replacing freshwater flows that are used to water ballfields. They’re going to be looking at recharge—they have wells in the Ogallala in and around the city of Garden City. They’re going to look at a myriad of things, but one of them they want to look at is what the potential for recharge is.”
How 65 Farmers Reduced Their Water Usage by 20%-Plus
Streeter also stresses that volunteer conservation—or more to the point, more efficiently using water—is a part of the state’s plan to slow depletion of its groundwater. He points to a Local Enhanced Management Area (LEMA) near Hoxie in Sheridan County. The LEMA, adopted locally in 2012 by Groundwater Management District (GMD) No. 4, involves about 65 farmers in a 100-square-mile area who are reducing water consumption by approximately 20%.
Specifically, the agreement allows 55 inches of irrigation per water right to be consumed on a rolling five-year total. “Those folks looked at their average water use historically and set a threshold of 11 inches for everybody, per year. That’s where the 20% came from.
“That’s significant because they did not penalize anybody who was using at or below the threshold, who … had already conserved.” In other words, participants who have already reduced do not have to save more, at least not as a percentage of what they were using before the agreement was reached.
“I think in the first three years of their LEMA, they’ve actually done better than a 20% reduction. I think they’re about 23.” Streeter notes, however, that in those three-plus years, “Mother nature has helped us, too. But we are seeing good reductions in pumping.”
Why That Successful Model Has Yet to Be Replicated
While the Hoxie-area LEMA shows promise, it is the only agreement of its size and kind statewide. Other smaller plans have been put in place. Also, a similar legal entity called a Water Conservation Area (WCA) was passed in 2015. The latter basically allows for a water user or a group of water users to form a body similar to a LEMA, but with one less level of government having to approve it. To date, however, no such WCA bodies have been formed.
The fact that both WCAs and LEMAs have had such a slow start is partly because both can be vetoed by just one farmer in the proposed district. While that district can be redrawn to exclude the opposition, the latter would simply draw water from a source shared by the neighbors who did opt in to conserve. That, in turn, would allow those who didn’t agree to conserve to benefit from the sacrifices of others in a very tangible way.
According to Streeter, reluctance to form additional WCAs and LEMAs is due to high post-drought commodity prices and interested parties wanting to see the groundwater effects and economic impact of the Sheridan County LEMA. “Now that we’ve seen a positive response in the aquifer in western Sheridan County and preliminary good results from the economic study looking at the impacts inside and immediately outside the LEMA boundaries,” says Streeter, “I am hopeful we will see more LEMA development along with … interest in WCA development over the High Plains Aquifer.”
Declines, and Efforts to Slow It, Continue
Meanwhile, the state’s aquifers, including the Ogallala, continue to be depleted. A map from the Kansas Water Office (at right) shows decline in groundwater in the majority of the state from 2015 to 2016. According to the Texas Comptroller, losses to the aquifer between 2001 and 2011 equated to a third of its cumulative depletion during the entire 20th century. Streeter, though, points to measures the state has underway that he believes will help solve what looks to be an impending shortage. He describes two of them:
“All active irrigation wells, about 20,000, are metered and annual water use reports are mandatory,” he says. “Additionally, we have an annual well measurement program on the 1,400 wells throughout the High Plains. Depending on the year, we have an additional 600 wells measured in areas of interest.
“So,” he continues, “we have pretty accurate data that come in every year on how much water’s used. We’ve done it for years and years, and have good information on what the aquifer’s doing.”
“Then, the last thing I would say is we’re demonstrating technology out there. Particularly, the use of soil moisture probes to tell an irrigator when to turn that sprinkler on and when to turn it off and to trust it. We’re seeing some very good results from those moisture probes in irrigation water management.”
Such results were recently studied by the Natural Resource Conservation Service (NRCS) and did show probes are reducing water usage. Reviewing the Ogallala Aquifer Initiative, a cost-share program started in 2009 to help farmers apply water-saving technology in their fields, the “NRCS analysis … estimated reduced water withdrawals of at least 1.5 million acre-feet, or 489 billion gallons of water, from 2009 through 2013 and an energy savings equivalent of almost 33 million gallons of diesel fuel due to reduced irrigation.”
For an excellent primer on artificial recharge, see “Recharge: Groundwater’s Second Act.” The article offers comparisons on cost of artificially recharging groundwater versus that of reservoir expansion and desalination, as well as explanations of recharge techniques and a look at recent recharge projects in California, where the study’s authors are based.
Also, see the USGS article, titled “Aquifer Storage and Recovery.”
For more information on the Equus Beds recharge project, see http://ks.water.usgs.gov/equus-beds-recharge.
Thanks to the following for their help in putting this story together.