Preparing for future water shortages
Perhaps the only positive thing about the 2011 drought in Texas, the state’s worst single-year drought in history, is that it ended up being the mother of all teaching moments. The lessons learned are not pleasant, but addressing them will give the state a fighting chance when the next major drought comes around.
Scientists at The University of Texas at Austin are at the forefront of research to make the state better prepared for future water shortages. The benefits of this research don’t end at the state’s border. Once most fiercely concentrated in Texas, this year the drought spread its warm embrace to more than half of the continental United States. By early September, 63 percent of the country was in moderate to exceptional drought.
So what have we learned from the 2011 drought? Here are five key lessons.
#1 Wake Up, Texas
We learned Texas is not ready for an acute one-year drought, much less several years of drought such as the state experienced in the 1950s.
Most Texans are familiar with the effects of the 2011 drought. Watering restrictions in the big cities may have only been minor hassles, but news images of starving cattle and raging wildfires made it hard to ignore the immensity of the tragedy. Some estimates put agricultural losses at more than $7 billion. Irrigation water for rice farms and agriculture downstream from Austin was cut off by the Lower Colorado River Authority for the first time in more than 70 years. Twenty-three public water systems reported having less than six months’ water supply. The town of Spicewood Beach near Austin completely ran out of water and began trucking it in at great expense to keep household taps flowing.
Part of the problem was that the state’s water storage infrastructure hasn’t grown as fast as its population. Since 1980, per capita water storage in the state has fallen 30 percent.
So what can we do?
“Just like your financial portfolio, you want to have your water portfolio diversified,” says Robert Mace, who earned his Ph.D. at the university in 1998 and is now deputy executive administrator at the Texas Water Development Board (TWDB).
“We need to broaden our water sources and be more flexible,” Scanlon agrees.
She and other scientists at the university work regularly with the TWDB on drought issues. Experts have proposed a range of new water projects, including more surface reservoirs, desalination, and reuse systems. Two of Scanlon’s favorite options are conservation and aquifer storage and recovery.
“Conservation is the cheapest solution,” she says.
Aquifer storage and recovery (ASR) refers to storing surface water in natural underground aquifers during times of excess and pumping it out during times of scarcity. ASR does not incur losses from evaporation as occurs in surface water. San Antonio has the country’s third largest ASR facility. At the height of the drought, the Twin Oaks ASR facility supplied about 20 percent of San Antonio’s demand. Scanlon plans to study the feasibility of ASR in the Dallas area, which sits above the heavily depleted Trinity aquifer.
#2 It Can Get Worse
To geoscientists, the 2011 drought was not especially remarkable. Heck, even the six-year drought of the 1950s, used by water planners as the worst-case scenario, was minor compared with the megadroughts typical for the state.
Jay Banner, director of the university’s Environmental Science Institute, has been collaborating with colleagues at the University of Arkansas and the Guadalupe-Blanco River Authority on a study using tree rings to reconstruct the history of Texas droughts for the past five centuries. This study, in combination with others in Texas, finds a number of droughts longer and more severe than the 1950s drought. Some lasted 20 or 30 years. Since the 1500s, droughts lasting a decade or more have occurred in Texas at least once a century.
As if that weren’t ominous enough, some climate models predict more frequent and severe droughts in Texas during the coming century. Whether you believe those models or not, Banner says it’s likely the state will again experience a megadrought unlike anything we’ve seen in our lifetimes.
“To be truly conservative, I think you have to prepare for the ‘worser’ case scenario of these 20- or 30-year megadroughts rather than the six-year drought we have in the historical instrumental record,” says Banner.
Building that kind of infrastructure may be costly up front, but he warns it’s much more expensive to wait until we’re in a severe drought to try and secure new sources of water. Still, given how low our current capacity is, Scanlon says a more realistic goal would be to prepare for a repeat of the 1950s.
#3 Cool the Power
Our electrical power supply is vulnerable to water shortages.
Most of the 250 or so large power plants in the state rely on a steady stream of water for cooling, mainly from lakes and rivers. Officials with the state’s power grid warned that if the 2011 drought continued through 2012, some power plants would have been forced to stop operating.
Thankfully, a wet winter took the edge off the drought in much of the state, and there were no blackouts. Still, peak electric power demand in the state broke records in July 2012. It’s not clear how the power supply would have been affected if the drought had persisted at the previous year’s levels.
Power plants consume only about 3 percent of the water in the state. That’s because most of the water returns to lakes and rivers after passing through the plants, but on any given day, power plants need access to a lot of water to keep things running — about 43 percent of all water withdrawals in the state, according to the U.S. Geological Survey.
Scanlon is analyzing power plants across the state to identify those most vulnerable to drought. She’s also looking at the efficiency of different cooling technologies in a study for the state comptroller’s office.
“We don’t want drought to impact the economy of the state,” says Scanlon. “We don’t want the plants to run out of water to maintain energy.”
Scanlon says that for the most vulnerable plants, it would make sense to develop alternatives to surface water for cooling. Her preliminary research suggests drilling groundwater wells or using aquifer storage and recovery might be the most cost-effective ways to buffer power plants from extreme drought.
#4 Improve the Models for Forecasting Rainfall & Temperature
Even the best minds and fastest computers have a hard time forecasting a drought’s severity or duration.
In October 2011, experts from the National Oceanic and Atmospheric Administration(NOAA) concluded that Texas was two to three times as likely to have precipitation levels that were below normal through the following May as above normal. But in fact the winter turned out to be extremely wet for many parts of the state.
Rong Fu, a professor in the university’s Jackson School of Geosciences, began exploring the reasons for the unexpected rains. Working with researchers in NOAA’s Climate Prediction Center, she and postdoctoral researcher Nelun Fernando discovered one reason: an atmospheric circulation pattern called the North Atlantic Oscillation was positive and unusually strong, blocking cool arctic air from escaping south. That allowed warm, wet air from the Gulf of Mexico to dump rain across Texas.
Fu and Fernando have also discovered a key ingredient for making a run-of-the-mill drought extreme. It turns out that the four worst droughts of the past century all had one thing in common: Each time, summer drought was preceded by warm, dry air blowing from the west into Texas during the spring. It was like leaving a Texas-shaped cookie in an Easy-Bake oven for too long, which happened in 2011.
Based on these and other insights, Fu is evaluating climate models so policymakers at the state and local levels understand which ones are most reliable for long-term planning.
#5 Improve the Water Level Forecasts
Water planners and businesses need better long-range forecasts of water levels in rivers and lakes.
Brenner Brown, a member of the state’s Drought Preparedness Council, says such forecasts would have helped the council in 2011 identify local water entities that were going to be struggling before the situation got really bad.
“Any kind of forecasting component we can develop to help us anticipate the impacts will definitely improve our emergency response,” says Brown.
Liang Yang, a professor in the Jackson School of Geosciences, and David Maidment, a professor in the Cockrell School of Engineering, co-direct the university’s Center for Integrated Earth System Science. They are building a set of computer models that will forecast, among other things, surface water availability six to 18 months in advance. With that information, local water systems could decide whether to establish water use restrictions or even cut off some users. Power plant operators could start activating emergency management plans earlier.
This kind of water forecast could also enable something Maidment, Scanlon and others have been talking about lately: a market for trading water rights. Texas uses a system called prior appropriation to allocate surface water. In times of scarcity, the owner of a more senior water right can make a “call” requesting the Texas Commission on Environmental Quality to limit the water usage of more junior rights holders.
“Right now the only policy controls we have are, ‘Turn off your pump’,” said Maidment. “That’s all we’ve got. And it’s a pretty blunt instrument.”
He and others have suggested that senior water rights holders should be able to easily sell their rights to more junior rights holders from day to day. It’s technically possible today, but the process is slow and cumbersome. By putting a monetary value on the right to pump itself, market forces might be able to wring out efficiencies more easily than regulators can. Having a robust forecast of water supplies months in advance would help buyers and sellers set a price for water rights.
Last February, Yang and Maidment organized a day-long Water Forum, which brought together 130 experts from across the state including researchers from The University of Texas at Austin and Texas A&M University, local water authorities such as the Lower Colorado River Authority, and scientists and policymakers from an alphabet soup of state agencies including the Texas Water Development Board (TWDB), Texas Commission on Environmental Quality (TCEQ) and Texas Parks and Wildlife Department (TPWD).
Several new research projects and collaborations have sprung from that meeting. For example, Yang and Maidment are now working with John Nielsen-Gammon, Texas state climatologist and a professor at Texas A&M University, to prepare seasonal water balance forecasts for state agencies.
“The drought of 2011 makes me appreciate more that climate and hydrological scientists must work intimately with other scientists and policymakers to address the broad impacts of extreme weather and climate disasters,” says Yang.
Banner image: Terry Hash pauses after searching in the cracked soil for some cotton seeds in his 175-acre cotton field in Garfield in August of 2011. Hash planted 800 acres of cotton, corn, wheat and sorghum, and almost all of it was destroyed by the drought. Photo: Jay Janner/AMERICAN-STATESMAN