Here’s the release from Kansas State University (Greg Tammen):
A new Kansas State University study finds that the over-tapping of the High Plains Aquifer’s groundwater beyond the aquifer’s recharge rate peaked in 2006. Its use is projected to decrease by roughly 50 percent in the next 100 years.
David Steward, professor of civil engineering, and Andrew Allen, civil engineering doctoral student, Manhattan, published those findings in the recent Agricultural Water Management study “Peak groundwater depletion in the High Plains Aquifer, projects from 1930 to 2110.” It is the first paper to look at and quantify peak aquifer depletion.
Researchers looked at the historic and projected future groundwater use rates of the eight states comprising the High Plains Aquifer. The aquifer runs under South Dakota, Wyoming, Nebraska, Colorado, Kansas, Oklahoma, New Mexico and Texas — eight agriculturally important states. It provides 30 percent of the irrigated water for the nation’s agriculture and is pivotal in food production.
This latest study builds on the 2013 Proceedings of the National Academy of Sciences study in which Steward and colleagues forecasted the future of the Ogallala Aquifer in Kansas. Researchers expanded their projections to include wells in Kansas that were both depleted and steady in their historic groundwater levels as well as the eight states that rely on the High Plains Aquifer. A total of 3,200 Kansas wells and 11,000 wells from the other seven states were studied to understand their water depletion processes.
Allen wrote the computer code necessary to analyze massive amounts of geographic information systems data about the more than 14,000 wells using the aquifer. A logistic equation was developed to apply more than 300,000 well measurements to create a historical record of its water level and also its projected water level through 2110.
“When we did the Kansas study, it really focused on those wells in Kansas that were depleting,” Steward said. “We came up with a set of projections that looked at how long the water would last and how the depletion process would play out over time. With this study, we wanted to learn how the depletion in various locations plays into a larger picture of the aquifer.”
Steward and Allen found that the High Plains Aquifer’s depletion followed a south to north progression, with its depletion peaking in 2006 for the entire High Plains Aquifer. Overall, researchers saw that some portions of the aquifer are depleting while others are not. Texas peaked in 1999, New Mexico in 2002, Kansas in 2010, Oklahoma in 2012 and Colorado is projected to peak in 2023. Nebraska, South Dakota and Wyoming are not projected to reach peaks before 2110.
“We are on a declining trend right now for water use in irrigated agriculture,” Steward said. “As we project what happens in the future following the existing water use patterns, the amount of depletion and the amount of water that comes out of the aquifer will decrease by about half over the next 100 years.”
Additionally, researchers saw that the water depletion rates for each state in the High Plains Aquifer follow a similar bell-shaped curve pattern as the one for oil depletion in the U.S. modeled by the Hubbert peak theory.
While water is a finite resource, Steward said the intent behind the study is not raise alarm, but rather encourage proactivity to manage and preserve this resource.
“This study helps add to the dialogue of how is it that we manage water and the effects of the choices that we make today,” Steward said. “It has the same kind of message of our previous paper, which is that our future is not set; it’s not cast. The projections we show are projections based on the data we have available that show the trends based on how we used water. People have the opportunities to make choices about the way that things are done, and the findings from this study help add to the dialogue.”
The National Science Foundation and the U.S. Department of Agriculture funded the study. The U.S. Geological Survey and the Kansas Geological Survey contributed decades of information about the High Plains Aquifer and the Ogallala Aquifer for analysis.
Here’s the release from the US Department of Agriculture (Justin Fritscher):
Agriculture Secretary Tom Vilsack today announced USDA will invest about $8 million in the Ogallala Aquifer Initiative in Fiscal Year 2016 to help farmers and ranchers conserve billions of gallons of water annually while strengthening agricultural operations. The eight-state Ogallala Aquifer has suffered in recent years from increased periods of drought and declining water resources.
“USDA’s Ogallala Aquifer Initiative helps landowners build resilience in their farms and ranches and better manage water use in this thirsty region,” said Vilsack. “Since 2011, USDA has invested $74 million in helping more than 1,600 agricultural producers conserve water on 341,000 acres through this initiative.”
The Ogallala Aquifer is the largest aquifer in the U.S. and includes nearly all of Nebraska and large sections of Colorado, Kansas, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. It is the primary water source for the High Plains region. Covering nearly 174,000 square miles, it supports the production of nearly one-fifth of the wheat, corn, cotton, and cattle produced in the U.S. and supplies 30 percent of all water used for irrigation in the U.S.
Water levels in the region are dropping at an unsustainable rate, making targeted conservation even more important. From 2011 to 2013, the aquifer’s overall water level dropped by 36 million acre-feet, according to the U.S. Geological Survey.
USDA’s Natural Resources Conservation Service (NRCS) supports targeted, local efforts to conserve the quality and quantity of water in nine targeted focus areas through the Ogallala Aquifer Initiative (OAI), adding two new focus areas for fiscal year 2016, while continuing support for seven ongoing projects. These projects include building soil health by using cover crops and no-till, which allow the soil to hold water longer and buffer roots from higher temperatures; improving the efficiency of irrigation systems; and implementing prescribed grazing to relieve pressure on stressed vegetation.
The new focus areas include:
Middle Republican Natural Resource District in Nebraska: The project addresses groundwater quantity and quality concerns. The focus will be in areas where groundwater pumping contributes to high levels of stream flow depletion. Priority will be given to areas where groundwater pumping contributes to more than 48 percent of the overall aquifer depletion rate. The project will enable participants to voluntarily implement practices to conserve irrigation water and improve groundwater quality.
Oklahoma Ogallala Aquifer Initiative: This project will help landowners implement conservation practices that decrease water use. It includes an educational component that will educate citizens about water conservation and conservation systems. These systems include converting from irrigated to dryland farming and conservation practices that improve irrigation water management; crop residue and tillage management; nutrient and pesticide management; grazing systems; and playa wetland restorations. The targeted area includes places where great amounts of water are consumed. Focal areas will be heavily-populated municipalities in the aquifer region.
NRCS analysis of Environmental Quality Incentives Program (EQIP) conservation projects in the region, including those implemented through OAI, 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.
With the growing demand for water and drought conditions plaguing the West, NRCS is working with farmers and ranchers to help them implement proven conservation solutions on targeted landscapes to improve the quality of water and soil, increase water supplies, increase the infiltration of water into the ground, and make lands more resilient to drought.
This investment in the Ogallala region expands on USDA’s substantial efforts to help producers address water scarcity and water quality issues on agricultural lands. Between 2012 and 2014, across the United States, NRCS invested more than $1.5 billion in financial and technical assistance to help producers implement conservation practices that improve water use efficiency and build long-term health of working crop, pasture, and range lands. These practices include building soil health by using cover crops and no-till, which allow soil to hold water longer and buffer roots from higher temperatures; improving the efficiency of irrigation systems; and implementing prescribed grazing to relieve pressure on stressed vegetation.
…But irrigation soon could end on [Brant] Peterson’s southwest Kansas farm. The wells under his land in Stanton County are fast running dry as farmers and ranchers across the Great Plains pump the Ogallala faster than it can be replenished naturally.
Three of his wells are already dry.
Within five years, Peterson estimates, he likely won’t be able to irrigate at all.
Wet and dry: A country divided
While the east half of the country generally receives at least 25 inches of rain a year, much of the west is dryer.
This means much of our country’s corn and hogs are farmed west of the 100th meridian. Meanwhile, in the Great Plains, milo, or grain sorghum, has become a popular crop due to its reduced need for water, and cattle farming has long been popular out west…
Western Kansas’ only significant water source is the Ogallala…
The vast freshwater reservoir beneath the prairie formed 5 million to 10 million years ago as streams draining from the Rocky Mountains deposited water in the clay, sand and gravel beneath the Great Plains.
The water lay there undisturbed for epochs until enterprising homesteaders who settled the West discovered the liquid bonanza that would make their arid land bloom.
Now, in a geological blink of an eye, the Ogallala, which made the Great Plains the nation’s breadbasket, is in peril…
The disappearing water supply poses a twofold danger. It could end a way of life in a region where the land and its bounty have been purchased by the toil and sweat of generations of farmers.
It also threatens a harvest worth $21 billion a year to Kansas alone and portends a fast-approaching, and largely unstoppable, water crisis across the parched American West.
With water levels already too low to pump in some places, western Kansas farmers have been forced to acknowledge that the end is near. That harsh reality is testing the patience and imagination of those who rely on the land for their livelihoods.
As they look for survival, farmers are using cutting-edge technologies to make the most efficient use of the water they have left. They’re contemplating something almost unimaginable just a generation ago: voluntary pacts with their neighbors to reduce irrigation.
And many are investing their long-term hopes in an astronomically expensive water transportation project that isn’t likely ever to be built.
The Arkansas River, which once flowed out of Colorado into western Kansas, is nothing but a dry ditch now, its riverbed reduced to a rugged obstacle course for all-terrain vehicles.
And average rainfall here is just 14 to 16 inches a year, nowhere near enough to replace the water that farmers draw from the Ogallala.
Kansas enjoyed a rainier-than-normal spring this year, easing several years of drought conditions throughout the state. But the relief is temporary.
The storms that soaked the state in recent months won’t alter the Ogallala’s fate, experts say…
Once emptied, it would take 6,000 years to refill the Ogallala naturally…
The Ogallala Aquifer supplies water for 20 percent of the corn, wheat, sorghum and cattle produced in the U.S.
It sprawls 174,000 square miles across eight states, from South Dakota to Texas, and can hold more than enough water to fill Lake Huron and part of Lake Ontario.
But for every square mile of aquifer, there’s a well. About 170,000 of them. Ninety percent of the water pumped out is used to irrigate crops…
Over the years, there have been multiple attempts to address the rapid decline of the aquifer. Water rights holders in much of western Kansas had to install flow meters in all their wells starting in the mid-1990s. Soon all wells in Kansas will have to be metered. And the state government has stopped issuing new permits to pump water from the Ogallala in areas of western Kansas where water levels have dropped the most.
Now, Kansas Gov. Sam Brownback has pledged to make water policy a central pillar of his administration. The final draft of his 50-year “water vision” for the state, released in January, outlines an incentive and education-based approach focused on encouraging voluntary, coordinated conservation efforts by the farmers who have the most to lose by the aquifer’s decline.
So far, however, farmers have agreed to limit water use in just part of two northwestern counties. A group of farmers in Sheridan and Thomas counties established a Local Enhanced Management Area, or LEMA, in 2012 to cut water use by 20 percent over five years.
It seems to be working: In the first year, participants in the LEMA used about 2.5 inches less water for irrigation than their neighbors and produced just two bushels less per acre, on average.
A proposal to create another LEMA in west-central Kansas was voted down last year by water rights holders.
“The problem is everybody wants to be democratic, and you have people for and you have some people against,” said Bill Golden, an agricultural economist at Kansas State.
It isn’t easy to convince individuals to put their profits at risk to preserve a common resource, especially when some farmers have more water left than others, Golden said.
“But I think that we will probably see more LEMAs in the coming years,” he said. “That is the most acceptable answer. I mean, we’re going to run out of water. Nobody’s talking about saving the aquifer and not using the water. The question is, can we extend the life of the aquifer and make it a soft landing?”
For now, that leaves individual farmers making their own decisions about how best to manage water on their land.
Ten miles east of Peterson’s farm, in Grant County, Kan., Clay Scott parked his Dodge pickup on a country road and reached for his iPad.
A few hundred feet away, a solar panel planted in a field of wheat powered a probe that measures soil moisture at different depths.
Right now the probe told Scott’s iPad that he could hold off on watering the field. His sprinklers lay idle.
“People think that we waste our water out here,” Scott said, “and we just kind of grin because we work so hard to use that water.”
In addition to the soil moisture probes linked to his iPad, Scott consults satellites and radar data to track every shift in the weather and drop of rain that falls in his fields so he can minimize irrigation. He uses low-till techniques to preserve the soil and experiments with genetically engineered drought-resistant corn. He installed more efficient nozzles on his center-pivot sprinklers.
And he’s trying out a new device called a “dragon line,” which drags perforated hoses behind a center pivot to deposit water directly on the ground, reducing pooling and evaporation.
Scott’s version of high-tech farming would be unrecognizable to his great-grandfather, who homesteaded in nearby Stanton County around the turn of the century.
Still, despite all his efforts, Scott knows there will come a day – sooner rather than later if nothing is done – when irrigation is no longer viable in this part of Kansas.
The effects of the depleted aquifer already can be felt on Scott’s farm, where he’s had to reduce irrigation by 25 percent.
Some of his two dozen wells are pumping just 150 gallons per minute now, down from thousands of gallons per minute when they were first drilled. And as the water table drops, the energy costs of pumping from deeper underground have become higher than the cash rents Scott pays on the fields he leases.
“We’ve gone through periods where we re-drilled and tapped all but the very lowest water,” Scott said. “There are places we don’t pump the wells anymore.”
As an elected board member for the local Groundwater Management District, Scott hopes that he’ll be able to shape conservation policies that will enable his children to continue farming after him. He sees the situation in California, where the state has forced farmers to cut water use, as a cautionary tale. If farmers in Kansas don’t find ways to conserve enough water on their own, the state could enforce water rationing.
“I’ve got three boys, and a couple of them have already talked very seriously about coming back to the farm, and I’d like them to have the opportunity and ability that I’ve had to grow crops and livestock, even in a drought,” he said.
Scott’s long-term hopes rest in the construction of an $18 billion aqueduct that would import high flows off the Missouri River to water crops grown in western Kansas.
As conceived by the U.S. Army Corps of Engineers, the concrete ditch would stretch 360 miles from east to west across Kansas with 16 lift stations and massive reservoirs on either end. The proposal was met with opposition – and not a little ridicule – by the legislature in Topeka, as state lawmakers struggled to close a $400 million budget hole.
“We’re not working on it at this point,” Earl Lewis, assistant director of the Kansas Water Office, said in an interview.
Missouri Gov. Jay Nixon dismissed the aqueduct as a “harebrained” scheme that would divert river water needed for barge traffic and municipal use.
But in western Kansas, it doesn’t seem like such a crazy idea.
“When they’re flooding in the Missouri River and cities are sandbagging, it sure seems to us like we have an answer to their problems,” Scott said. “Nobody wants to build a house and see it flooded; nobody wants to plant a field and watch it wither.”
Fervent support for the project speaks to the urgency felt by Scott, Peterson and other farmers and ranchers whose livelihoods and communities depend on irrigation. They’re hoping to convince the federal government to kick in funds for the aqueduct. And they’re looking into the possibility of building it through a public-private partnership, like a toll road. Farming cooperatives in California and Colorado have expressed interest in the project, they say, and want to explore extending it farther west.
A federal engineering bailout for western Kansas isn’t very likely, however.
Kansas Sen. Pat Roberts, the Republican chairman of the Senate Agriculture Committee, said in an interview that such a costly project would be a nonstarter under Congress’ current budget caps.
“In all honestly, it’s a front-burner issue for folks in southwest Kansas, but to build that kind of aqueduct would be billions of dollars, and I just don’t think that’s feasible at this point,” Roberts said.
Barring the construction of an aqueduct, rural communities that depend on the Ogallala face a bleak future.
The state would have to cut its irrigated acres in half today to get anywhere close to sustainability, said Golden, the agricultural economist from Kansas State.
But it isn’t as simple as turning off the sprinklers.
“People survived out here on dryland farming. I can do it,” Peterson said, using the term “dryland” to refer to growing crops without irrigation. “Here’s the cost: My community is going to wither away.”
An irrigated field in southwest Kansas produces more than eight times more corn per acre on average than a field that isn’t irrigated, according to the Kansas Department of Agriculture. Land values would drop. The loss of equity and tax base would mean fewer farmers and bigger farms, consolidated school districts, and impoverished towns with declining populations.
Like any economy dependent on mining a finite resource, this one is headed for a bust, and the farmers know it.
“We can’t wait another 30 years to get our policy right,” Scott said. “The drought in California is showing what living in denial can do.”
Keith Gido, professor in the Division of Biology; Josh Perkin, 2012 Kansas State University doctoral graduate; and several co-authors have published “Fragmentation and dewatering transform Great Plains stream fish communities” in the journal Ecological Monographs.
The article documents a reduction in water flow in Great Plains streams and rivers because of drought, damming and groundwater withdrawals. This is causing a decrease in aquatic diversity in Kansas from stream fragmentation — or stretches of disconnected streams.
“Fish are an indication of the health of the environment,” Gido said. “A while back there was a sewage leak in the Arkansas River and it was the dead fish that helped identify the problem. Children play and swim in that water, so it’s important that we have a good understanding of water quality.”
Several species of fish — including the peppered chub and the plains minnow — were found to be severely declining in the Great Plains during the ecologists’ field research, which compared historic records to 110 sampling sites in Kansas between 2011-2013. Both fish species swim downstream during droughts and return during normal water flow, but the construction of dams, or stream fragmentation, prevents fish from returning upstream.
“The Great Plains region is a harsh environment and drought has always been a problem. Historically, fish were able to recover from drought by moving,” Gido said. “They could swim downstream and when the drought was over, they could swim back. Now, there are dams on the rivers and the fish are not able to recover.”
Streams in the Great Plains region have more than 19,000 human-made barriers. Gido estimates that on average, stretches of streams in the Great Plains are about six miles long. In surveying Kansas’ streams and rivers, the researchers discovered numerous small dams that do not allow enough habitat for the fish to complete their reproductive cycles. Moreover, the fish are unable to migrate in search of suitable habitat.
“Groundwater extraction exasperates the drought, and the damming of the rivers inhibits the fish from being able to recover from those conditions,” Gido said. “This is unfortunate, but there are some things we can do to help.”
Gido suggested a renewed focus to conserve water, reduce dams and make fish passageways like the one on the Arkansas River under Lincoln Street in Wichita. During the planning for the reconstruction of the Lincoln Street Bridge and the dam over the river, the city worked with wildlife agencies to build a passage that would allow fish as well as canoes and kayaks to navigate through the structure.
Similar structures could be constructed on the Kansas River to help fish migrate.
“The plains minnow is still found in the Missouri River and could recolonize the Kansas River — where they used to be the most abundance species — if there was a fish passage through some of the dams.”
Significant portions of the Ogallala Aquifer, one of the largest bodies of water in the United States, are at risk of drying up if it continues to be drained at its current rate. Courtesy of MSU
Kansas Aqueduct route via Circle of Blue
Ogallala aquifer via USGS
Republican River Basin by District
South Fork of the Republican River
From the Kansas State Research and Extension via KTIC:
The 2015 Central Plains Irrigation Conference and Exposition will take place Feb. 17-18 at the City Limits Convention Center, Colby, Kansas. The popular annual event focused solely on irrigation-related topics is hosted in Kansas every third year. Sponsors include Kansas State University, Colorado State University, the University of Nebraska and the Central Plains Irrigation Association.
The conference portion of the event will include many technical irrigation sessions presented by academic researchers from the areas of agronomy and irrigation engineering, for example, as well as representatives from governmental agencies such as the U.S. Department of Agriculture’s Agricultural Research Service.
Session topics include the crop water budget, optimizing crop water productivity in a variable climate, sensor technologies for irrigation management, advancements in subsurface drip irrigation and center pivot irrigation, updates on groundwater issues and crop options for deficit irrigation.
“The overall theme for this event from a crop water standpoint, particularly for western Kansas, is management with limited water supply,” said Danny Rogers, K-State Research and Extension professor and irrigation engineer. “But, the management issues we talk about with irrigation have application whether you have full water or limited water capabilities. There will be something for everyone.”
Bob Gillen, head of tri-center operations for K-State Research and Extension’s Western Kansas Agricultural Research Centers, will present the first day general session on lessons from 100 years of agricultural research in northwest Kansas. Ajay Sharda, assistant professor in K-State’s Department of Biological and Agricultural Engineering, will lead a general session discussion about the potential of technology and precision agriculture on the second day of the event.
The conference includes a menu-driven program, Rogers said, so participants can choose what to attend during the two days. The exposition side of the event will allow for industry representatives and irrigators to interact.
“Producers can come in and see, touch and talk about the new sprinkler options, soil sensors, plant health sensors, potentials for aerial sensors and other items out there,” Rogers said. “It’s a chance to have one-on-one conversations with industry folks, specialists and fellow irrigators.”
For a full list of sessions and presenters and the registration form, visit http://www.ksre.ksu.edu/sdi/REvents/CPIAprog.html. Register early by Jan. 30 at a discounted rate of $85 per person. After Jan. 30, registration is $100 per person. The fee covers access to technical and general sessions, the exposition and on-site meals. For more information, contact Donna Lamm at 785-462-7574 or firstname.lastname@example.org.
More Ogallala Aquifer coverage here. More Republican River Basin coverage here. More Arkansas River Basin coverage here.
Western Kansas is heavily dependent on the Ogallala Aquifer. But since 1950, that ancient supply of underground water has been rapidly depleted by irrigation. That irrigation produces corn, which is fed to livestock to support the beef and, more recently, dairy industries, which are the foundation of the western Kansas economy. But water levels have dropped so low in parts of more than 30 counties that irrigation pumps can no longer be used there. That’s why rivers in western Kansas are little more than dry stream beds.
Mark Rude is tracking the depletion of the aquifer for a groundwater management district in the heart of the affected area.
“We’re only 9 percent sustainable with that 2 million acre-feet that we use in southwest Kansas,” Rude says. “And 9 percent sustainable is a very formidable number, because you can’t conserve your way out of that.”
In other words, 91 percent of the water currently being pumped would have to be shut off just to keep the aquifer from declining any more. But if the water doesn’t come from the aquifer, where could it come from? The 2011 flooding on the Missouri River gave Rude and others an idea about how to answer that question. While devastating to those along the river, the flood looked like an opportunity.
“Folks who realize the deep value of water in western Kansas looked at that and go, ‘Wow, if we only had a couple days of that flow we could fill the aquifer, and we’d all be happy,’” Rude says.
Rude looked into that idea, and rediscovered the 1982 study proposing a system to capture excess water from the Missouri River and store it in a huge, new lake near White Cloud in the northeastern corner of the state. It would then be pumped uphill through an aqueduct to western Kansas. There it would be stored in another new lake — by far the largest in the state — for distribution.
The cost was estimated at $1,000 per acre-foot of water delivered. With that price tag, the concept was dead on arrival. But recently, the Kansas Water Office told the committee charged with updating the old study that the cost is now closer to $500 per acre-foot. The savings are due to lower interest rates. Cost is a concern for committee member Judy Wegener-Stevens, but it’s not the only reason she’s opposed to the project.
“I don’t feel an aqueduct should be built,” Wegener-Stevens says. “I feel that people in western Kansas have been pumping water unconditionally, without any rules, for 40 years, and they have not used their resource very well.”
Wegener-Stevens, who lives in White Cloud, said the nearby Iowa Tribe of Kansas and Nebraska would fight a proposed aqueduct. They have rights to water in the Missouri River and are working to quantify those rights. There might also be objections from other states, even though the idea is to take only “excess” water. Throw in anticipated battles over property rights and environmental concerns, and some committee members say the aqueduct still doesn’t appear realistic.
But committee member Clay Scott isn’t willing to give up on the idea. Three generations of his family raise cattle and grow irrigated corn and wheat near Ulysses, in southwest Kansas. Scott points to an Arizona aqueduct called the Central Arizona Project as proof that a Kansas aqueduct is feasible. He says a reliable source of water is vital to the future of his family’s farm.
“I’ve got three boys that are looking to maybe come back to the farm, but, you know, it takes a lot of acres in western Kansas to support a family — especially coming through these last three years of drought,” Scott says. “It’s a challenge to tell your boys that there’s an opportunity. There’s a future for you here.”
Scott and other members of the advisory committee say the first priority should be some sort of compact with other states and Indian tribes to secure rights to Missouri River water. Then they can worry about all the other obstacles to the project. Earl Lewis, the assistant director of the Kansas Water Office, agrees with that approach.
“Moving forward and investing considerable time and funds into pursuing a project that doesn’t have the legal security of a water right or some kind of compact doesn’t make a lot of sense,” Lewis says.
Even if the Missouri River doesn’t pan out as a water source, Lewis says there may be other options. State law could be changed to make it easier to transfer surplus water to western Kansas from other parts of the state. And Kansas may be able to get some financial help from Colorado, in exchange for providing water to ease shortages on the Front Range. But it will be up to others to explore those options and others. The advisory committee’s charge was solely to update the aqueduct study and make recommendations. Those recommendations are due by the end of January.
Wells are depleting the High Plains Aquifer at an alarming rate, according to a study released last week by the U.S. Geological Survey.
“The measurements made from 2011 to 2013 represent a large decline,” said Virginia McGuire, USGS scientist and lead author of the study. “This amount of aquifer depletion over a two-year period is substantial and likely related to groundwater pumping.”
The aquifer, also known as the Ogallala Aquifer underlies 175,000 square miles in Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas and Wyoming.
Wells began tapping the aquifer heavily in the 1930s and 1940s, and the acreage irrigated expanded to 15.5 million acres in 2005 from 2.1 million acres in 1949.
The total water stored in the aquifer in 2011 was estimated at 2.92 billion acre-feet (951.5 trillion gallons). Pumping in two years depleted that by 36 million acre-feet (11.7 trillion gallons), causing an average drop in the aquifer of 2.1 feet. The overall rate of decline in the entire aquifer since pre-development is 267 million acre-feet, or 8 percent, resulting in a drop of 15,4 feet through 2013.
The change has been most significant in Texas, where levels dropped 44 feet in some places in the 2011-13 study period and 256 feet since pumping began. In some places, the well levels rose. With the highest rise since predevelopment recorded in Nebraska at 85 feet. Over time, Texas well levels have declined by 41 percent, and Kansas wells by 25 percent. Colorado dropped 14.3 percent over that same period, with more severe declines in the northern part of the state.
For the 2011-13 period, 7,460 wells were studied, 411 of those in Colorado. For the pre-development study, 3,349 wells were included, with 325 in Colorado.
“This multi-state, groundwater-level monitoring activity tracks water-level changes in all eight states through time and has provided data critical to evaluating different options for groundwater management,” said McGuire. “This level of coordinated groundwater-level monitoring is unique among major, multi-state regional aquifers in the country.”
Here’s the release from the United States Geological Survey (Virginia L. McGuire):
The High Plains aquifer underlies 111.8 million acres (about 175,000 square miles) in parts of eight States—Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. Water-level declines began in parts of the High Plains aquifer soon after the beginning of substantial irrigation with groundwater in the aquifer area (about 1950). This report presents water-level changes in the High Plains aquifer from predevelopment (generally before 1950) to 2013 and from 2011 to 2013. The report also presents change in water in storage in the High Plains aquifer from predevelopment to 2013 and from 2011 to 2013.
The methods to calculate area-weighted, average water-level changes; change in water in storage; and total water in storage for this report used geospatial data layers organized as rasters with a cell size of 500 meters by 500 meters, which is an area of about 62 acres. These methods were used to provide a raster dataset of water-level changes for other uses.
Water-level changes from predevelopment to 2013, by well, ranged from a rise of 85 feet to a decline of 256 feet. Water-level changes from 2011 to 2013, by well, ranged from a rise of 19 feet to a decline of 44 feet. The area-weighted, average water-level changes in the aquifer were an overall decline of 15.4 feet from predevelopment to 2013, and a decline of 2.1 feet from 2011 to 2013. Total water in storage in the aquifer in 2013 was about 2.92 billion acre-feet, which was a decline of about 266.7 million acre-feet since predevelopment and a decline of 36.0 million acre-feet from 2011 to 2013.
More coverage of the 2012 drought and its affect on the Ogallala Aquifer from Stephanie Paige Ogburn writing for KUNC. Here’s an excerpt:
In Northeastern Colorado, farmers growing food like corn and potatoes depend for water on a giant, underground reservoir. Called the Ogallala, or High Plains aquifer, this water source spreads across eight high plains states like a giant, underground lake.
In times of drought, farmers who use the aquifer for water take more of it. A report from the U.S. Geological Survey, published December 16, shows the 2012 drought significantly diminished the Ogallala’s water.
“The bottom line was, there was with the drought, increased pumping and you have decline of the water levels,” said Virginia McGuire, the U.S. Geological Survey scientist who authored the report.
Over the last six decades, Colorado has exceeded the aquifer’s resupply by 18.8 million acre-feet of water. An acre-foot is the amount of water needed to cover an acre of land one foot deep.
Between 2011 and 2013, the state used up 3 million acre-feet more than was recharged. Across most of the aquifer, other areas also used a whole lot of water during that period. Kansas and Texas, both hard hit by drought, caused the largest declines in Ogallala water levels.
McGuire, who has been tracking the aquifer’s water level for years, said she knew the drought would make an impact. She was a little surprised at how significant an effect it was, though.
“The story is drought was widespread and there were declines in most of the aquifer for the 2011 to 2013 time frame.”