Texas Tech University

Water Withdrawal

By: John Davis 

Cities, towns, farmers and energy companies keep pumping the water below us, and Texas Tech researchers are trying to keep the balance sheet in the black.

cracked dirt in forground, receding water in background

He calls them GRADES. And many of them have started to fail across the globe.

Venki Uddameri, director of Texas Tech's Water Resources Center said that we, living atop the South Plains of Texas, also live in a GRADE, which stands for Groundwater Reliant Agriculturally Dominant Environment. 

Considering that the South Plains produces about 30 percent of the nation's cotton, 15 percent of the livestock and most of those products depend on the groundwater below us, the area certainly fits Uddameri's definition. The South Plains is not failing yet as a whole, though human activities continue to deplete water resources faster than they can rejuvenate.

Recently, the system was taxed with hydraulic fracturing (“fracking”) in the southern region, he said. Though it takes far less water than agriculture, energy is one more industry tapping the well in an area already facing major depletion compared to the northern South Plains.

Water is “thicker” in the north, he said, meaning more water beneath the surface. Travel south, and the water depletes in depth. After 65 years of use, some areas of the southern Ogallala Aquifer no longer can serve as a reliable source of water, he said. Farmers have shifted to crops that don't need as much water or gone back to dryland farming as they compete with municipalities and energy companies.

“The water beneath us is like a bank account,” he said, sitting at a desk covered in stacks of paper and reference books. “If you start pulling more money than what you put in, at some point you won't have any money. That's what we're doing. Some areas already are affected. We have about 30 to 50 years for vast portions of aquifer.”

Uddameri said it's probably one of the oldest but best comparisons to the use of the Ogallala Aquifer underneath the South Plains of Texas. It also applies to areas in Africa, Asia, Australia and other parts of the globe. 

Municipalities use it to drink, wash clothes and water lawns. Farmers need it for crops and livestock. Now, energy companies use it for fracking purposes. It keeps animals, plants and people alive. It drives the region's economy. Everyone needs water, Uddameri said. 

The problem is, the Ogallala underneath the South Plains, a good 20 percent of the actual aquifer, doesn't recharge at the same rate as the northern parts. The whole water system stretches from Western Texas up to South Dakota. However, a geological barrier near the panhandle of Oklahoma prevents recharge from the north. Little, if any, makes it through from the top. 

green hay watered by center pivot irrigation
Because of dwindling water resources, farmers are switching to growing hay instead. After two years, hay crops are established and require much less water.

The arguments of how much and where are largely academic, Uddameri says, because the amount that might make it down into the aquifer is negligible compared to that removed.

While irrigation methods have improved, humans currently use about five and a half million acre-feet of water a year on the South Plains. That's a foot of water covering eight Lubbock counties (Lubbock County is 901 square miles).

Quick fixes and one-size-fits-all answers won't work, he said. Answers need to come from scientific research, and the answer for one area may not apply to another. 

That's what the Water Resources Center sets out to answer, he said. The operation takes a holistic approach to understanding the way water works. Rather than solve one problem or come up with one answer, he and other scientists try to interpret the whole picture not only to give the best advice for all entities to use, but also to assist policymakers in better water use.

“Where we are provides us a perfect test bed for studying GRADES,” he said. “What we do here not only really helps the region, but also it helps us to find ways to manage other GRADES in other parts of the world. This helps us to make sure others don't go down the same path.”

The Price of Performance

About a hundred years ago, the South Plains of Texas opened to settlement. While farming and ranching always have been a part of the fabric of this area, primitive technology and the low initial population kept aquifer water use fairly low.

That changed radically in the 1950s thanks to electrification and new drilling technologies, Uddameri said. Deeper drilling meant farmers could use the water to irrigate cotton crops. Initially, farmers plowed straight fields and flooded crops because water was so plentiful. The drought of the '50s also boosted water usage as farmers tried to raise crops in a hostile environment.

“You saw flood-and-furrow irrigation from the '50s to about the '70s,” he said. “Center-pivot sprinkler irrigation has largely replaced those methods. More recently, subsurface drip irrigation has replaced some of the pivot sprinklers, which was a significant technological shift toward better water conservation.”

In the Field: Uddameri looks for ways to conserve the water supply by using prehistoric water from sources below the Ogallala Aquifer.

The drought of the 1950s prompted community leaders to plan for the next one by building surface water reservoirs. Initially, the plan worked, and cities like Lubbock and Amarillo depended on Lake Meredith north of Amarillo.

Then, in 2011, Lubbock County received a paltry five inches of rain. The drought drained Lake Meredith to its lowest point, dipping to 26 feet in 2013 (record-high capacity for the lake was 101.85 feet in 1973), and municipalities had to find new sources of water, often choosing well water.  

Like any complex problem, Uddameri said, there is no one magic bullet cure-all. What works in one area might not work for another. That's why the water center and its researchers take a holistic approach to understanding the problem in multiple areas, he said.

Approved by Texas Tech's Board of Regents in 1965, the center's researchers study water resources in the region and work on sustainability, he said. Researchers deal with all issues related to water and interact with multiple water use organizations on campus to fully understand and sustain the available water resources for the economy.

“Our job is to provide and do good science, because we have the perfect location for doing this,” he said. “If you want to study water resource-dependent systems, it can't get any better than where we are. Our outreach mission helps the region improve water resources. We have people who work on technologies, people helping municipalities improve water resources and people finding out more about contaminants. We want to know how we improve water quality and how best to manage water. Rather than creating a product, we're looking to stop a product from disappearing.”

During its time, the center has helped many entities, municipalities and water districts by bringing the best possible science and technology to assist in creating good water policies. 

diagram of layers of water from ogallala and dockum aquifers
Researchers are looking at the Dockum aquifer as a resource for smaller communities. Water at the top of this aquifer is fresher than water at the bottom. Texas Tech researchers are trying to determine the best way to extract the fresh water without mixing it with the saltier water below.

One untapped source lies deep beneath the Ogallala, Uddameri said. The Dockum Aquifer lies about 1,200 feet below the Caprock, and offers an imperfect solution to a difficult problem.

The water is saltier (up to three times that of seawater in some places) and requires more treatment, he said. However, the saltiness is on a gradient. Closer to the top, the water is nearly fresh. The deeper you go, he said, the saltier it gets.

Now, scientists want to understand how to extract this water without disrupting the salt gradient so that the fresher top water can be used, he said. Cities like Abernathy, about 30 miles north of Lubbock, already are looking at the Dockum water as a potential municipal source. Uddameri said Texas Tech researchers also are looking at affordable ways these small towns can mix or even treat the lower-quality water in a cost-effective manner to make it potable. Perhaps, unlocking cheap desalination technologies can solve water problems in other parts of the state and the world.

“The population of Texas is going to double in next 50 years, and that means water demands are going to go up considerably,” he said. “We need to tackle the water problem. Like politics, water is local. Nonetheless, it's important that we not lose sight of the fact that we cannot look for policies that say they're going to have water at the cost of agriculture or something else. We have to improve conservation, policies and technologies at the same time. That's why our center does what it does.” 

Finding alternative sources to drinking water in the oil patch also is a major goal of researchers at Texas Tech, said Danny Reible, the Maddox Distinguished Engineering Chair in the Department of Civil, Environmental & Construction Engineering.

Water is necessary to fracking, and energy producers don't want to foul a well or vital components to the process by using low-quality water that may be easily attainable on-site, he said. Hydraulic fracturing or “fracking” uses a small amount of water overall compared to the state total, he said, but the draw on the local area can cause problems for others using the same resource.

For every gallon of oil pulled from the ground, energy producers extract about 10 barrels of water. The problem? It's often up to three times saltier than sea water. Many energy producers take this water and sink it back down into an injection well, thinking that it can't be useful for fracking with such a high salt content.

However Reible said he and others are researching how this non-potable resource can be used by energy companies to save money. Today's fracking technology now uses fewer chemicals to accomplish the same goal. A simpler fracking mixture means fewer problems with chemical fouling by using lower-quality water that often is close to or already at the well site, he said.

“This produced water from the deep subsurface generated from oil and gas certainly can be used for hydraulic fracturing,” he said. “Right now, most of that goes for disposal in deep injection wells because no one knows what to do with it.  We're looking at how we manage that more effectively. Every gallon of produced water used is one less of potable drinking water, and there's no good reason to pump fresh drinking water down the hole if energy producers can avoid it.

“Overall, 58 percent of total water use in Texas is used for agriculture. Municipalities 27 percent. Between them, 85 percent of water are those two areas. I can take all the water used by industry and cut it in half, and it wouldn't have near the impact of having a 10 percent improvement in agricultural use.”

In the Field

cattle in pen at feed lot
Cattle operations use much less water than growing crops, however many cattle operations exist in the northern South Plains region, where aquifer water is more plentiful.

Go back in time to the 1950s, and farming looked much different on the South Plains of Texas, said Chuck West, director of College of Agricultural Sciences and Natural Resources (CASNR) Water Center and project leader of Texas Alliance for Water Conservation (TAWC).

While we're used to seeing circular fields with a center-pivot irrigation system when we look out of an airplane window, it wasn't that long ago that farmers plowed straight fields and allowed water from their wells to pour down the furrows to irrigate them.

It wasn't a problem then, he said, and well output of 600 gallons per minute was more than enough water to irrigate easily. That meant, though, that farmers would flood their fields to get the coverage they needed. Crops closest to the well usually received more water than they needed. Crops farther down, maybe not so much. The tail water, or the excess produced from irrigation either drained away or was re-channeled into the field.

Overall, about 70 percent of the water made it to the plant roots. 

That shifted in the ‘60s, he said, when farmers in Nebraska adopted a locally invented center-pivot system. Instead of opening the well and running water down the furrows, water was moved around a circular field, first with sprinklers throwing water through the air, then eventually using drop-lines and special nozzles that sprayed or dribbled out the water to reduce evaporation.

“That technology alone changed water usage,” he said. “With the center pivot sprinklers, water efficiency jumped up to 85 or 90 percent. Advances in spray nozzle design further improve efficiency. Some nozzles make the water drip out in large droplets instead of a lot of fine droplets that evaporate.”

That 90 percent efficiency sounds great until you realize how much some parts of the Ogallala aquifer have declined. That's changing the landscape as to what producers grow and how they irrigate.

A more recent option developed in Israel called subsurface irrigation puts the water in the root zone about a foot beneath the soil surface and bumps the efficiency up to almost 98 percent. However, at up to $2,000 an acre for installation, this method won't replace most of the center-pivot systems. 

“That's tremendous progress from the way we used to do it,” he said. “There isn't a lot of subsurface irrigation out there yet. Pivot irrigation was put in a while ago in most of these fields, so it's already paid for. It would be easier for producers to modify the pivot spray systems with drip lines that drag along the soil surface than to tear the pivots out and put in subsurface drip.”

West said agricultural researchers strive to improve water use efficiency in many different aspects of production. The rub? Farmers depend on quality yield to make a profit, and the right amount of water translates into better yields and quality. Urban sprawl means fewer acres for crops. A growing worldwide population demands more from those fewer acres for food, meat and fiber.

center pivot irrigation system over field of open cotton bolls with sorghum growing in background
Center pivot irrigation revolutionized water usage on the South Plains. Irrigation efficiency with the center pivot system is 85 to 90 percent, compared to flood-and-furrow irrigation, which was about 70 percent.

The Ogallala is only one area facing water resource issues, he said. The Mississippi Delta and the Central Valley of California also face dwindling water resources.

“We do get worldwide attention at Texas Tech because of the seriousness of the problem and the vigor with which we are addressing it,” West said.

In a community-outreach effort, West said that CASNR created the Texas Alliance for Water Conservation (TAWC) to assist farmers with the water challenges they face. 

The group, funded by the state of Texas by a bill promoted by then-Sen. Robert Duncan (now chancellor), promotes water conservation through demonstration of water-saving irrigation technologies, increased producer awareness and improved management of major crops, such as corn, cotton and sorghum.

Through the programs, West and his team have taught local growers about important scientific phenomena that impact water usage. Evapotranspiration, for example, is the amount of water sucked out of the soil by the sun and the amount of water used by the planted crop and exhaled through the leaves. And on a hot summer day in West Texas, that amount can be immense, West said. About a third of an inch of water leaves through evapotranspiration every day.

On the TAWC website, farmers can input the type of crops they have and learn how much water should be applied and when. The program, based on years of Texas Tech research, automatically calculates for local weather so that farmers water not only when it's needed to replenish the soil, but also when it's critical during the plant's growth cycle to achieve the highest yields.

“Traditionally, a lot of producers didn't know those numbers,” he said. “They didn't know how much was in soil. So, a lot of them would turn irrigation rigs on all summer long. When in doubt irrigate. Most producers have gotten away from that because they don't have enough water anymore to support that luxury. We've tried to teach them how they can target that water where it's needed most in space and time. That is one very useful way to meet critical needs of the crop and avoid wasting water.”

Researchers also suggest monitoring soil water content with sensors three to four feet in the ground.  While somewhat expensive to rent, the devices give growers real-time data on soil moisture conditions.

Genetics might hold the answer to more water-efficient crops, and West said many Texas Tech researchers are improving water usage through genetic manipulation, such as low-water peanuts and cotton. Crop genetics research is supported by a combination of state and federal grants and private companies and foundations to locate desirable genes that make the plants more drought tolerant.

plots of turf grass in a greenhouse
Texas Tech researchers are looking at genetically modifying many plants such as food and fiber crops as well as turf to use less water.

Other Texas Tech faculty are testing drought-tolerant turf grasses and landscaping plants that homeowners can use, and fine-tuning water-efficient grapes for wine production.

The trick for all crops, he said, is finding the sweet spot in low water usage to make every drop count while producing a profitable yield. 

“Over the past 20 years, there's been good progress on cotton and corn breeding,” he said. “The goal is not necessarily to have higher yields at high irrigation input, but to minimize yield losses as irrigation becomes more limited. Much of the cotton and sorghum are grown out here as dryland (rain-fed) crops. Plains Cotton Growers Inc. estimated only 43 percent of the crops planted in 2015 on the High Plains of Texas were irrigated. Both dryland and irrigated crop yields benefit from breeding for drought tolerance because even irrigated crops need timely rains to produce profitable yields.”

The testing fields for future seed lines are high-tech these days, he said. Not only are students counting bolls of cotton, but specially designed cameras also scan the rows of crops looking for water-stressed plants. The way light reflects off the leaves can tell researchers which experimental seeds do well and which do not.

The TAWC project demonstrates water-saving irrigation technologies and improved crop management on 36 sites covering 5,300 acres in nine surrounding counties.

Rick Kellison, director for the TAWC, said each site represents a particular cropping system such as single-crop monoculture, multiple cropping, or forage for livestock. These sites are managed by 20 different producers, who were chosen by a producer board to reflect a realistic range of management styles.

All farming management decisions are made independently of the project leaders. The project collects production data and provides information to aid in producer decisions. The crops are monitored for use of irrigation water, water demand, yields, and input costs. Calculations are made of amounts of irrigation water conserved, crop water-use efficiency, and net economic returns. A survey revealed barriers to change, such as the high cost of water-monitoring technology.

“Specifically after the 2011 drought, we began to see vendors offering different types of irrigation technology. We went from zero technology to growers being overwhelmed with what to do and which technologies to pick. We don't say we think Technology A is better than Technology B. We're about getting that technology into growers' hands and trying to assist them on how it impacts a specific farming operation. We also thought the best way to share information with producers is through other producers. That's been our main method to help farmers use less irrigation, or even rainfall, and get the most out of it; while being as conservative as we can.”

The organization hosts field days in the fall and during the growing season where attendees can walk through a producer's field and evaluate how that grower implements water-savings techniques. The group also hosts a Water College once a year as a crash-course in conservation with speakers who cover primary crops in region and talk about technologies that conserve water.

Kellison said he's been pleased with the positive reception the outreach project has gotten and believes it serves as a source of non-biased information for growers. 

“I think, as a whole when we look at growers and environmental issues, farmers and ranchers are first conservationists,” he said. “They make a living off their land. It's to their advantage not to misuse their land. Our focus always asks, does what we're doing have the possibility to have a positive impact on growers. If it does, we'll try to do it.”