The Texas Water Development Board on Thursday approved the state’s newest water plan, basically a road map for how the state will meet its water demands over the next half-century amid a steady growth in population.
The population boom is expected to be especially acute in the Colorado River basin, home to Austin and Travis County, as well as parts or all of Bastrop, Blanco, Burnet, Fayette, Hays and Williamson counties — some of the fastest-growing areas of the country.
Population in the Colorado River basin is forecast to increase from 1.7 million people in 2020 to 3.2 million in 2070.
Likewise, annual municipal water consumption in the region is expected to nearly double over that period, outstripping current supplies by roughly 2050.
The plan is notable for being the first to be truly informed by the devastating 2011 drought, which led water planners to rethink the amount of available supplies.
The basin will have to look for new sources of water, said Jim Barho, a Burnet County official who is the vice chairman of the Lower Colorado water planning group, one of the regional groups whose reports formed the basis for the statewide plan.
Conservation remains “the quickest, easiest way to generate more water,” Barho said, adding that the region will see more emphasis on rainwater harvesting and on maintaining and restoring old, leaky pipes.
“A lot of systems are over 50 years old,” he said.
The region will likely see the construction of several more reservoirs in coming decades, he said, including one underway by the Lower Colorado River Authority in Wharton County, about 150 miles downriver of Austin.
In November, the LCRA awarded a $174 million contract to a Tennessee company to build the reservoir. The idea is to capture some of the water that otherwise would flow into the Gulf of Mexico, making it available to farmers and industry while easing demand on the Austin-area reservoirs.
Roughly 2 million cubic yards of material has been moved in that project, said Karen Bondy, who oversees LCRA water resources, at an LCRA meeting Tuesday. The reservoir is expected be completed by 2018.
Total water demand in the Lower Colorado River basin is projected to increase 24 percent by 2070, according to the state plan, while statewide water demand is expected to rise 17 percent.
The plan serves as a guide for the Texas Water Development Board as it decides how to dole out billions of dollars in low-interest loans in coming decades to spur the construction of heavy-duty water projects.
“This is the best plan yet, in my view,” said Bech Bruun, the state water board’s chairman. “It’s the most detailed and comprehensive.”
As in previous iterations of the state water plan, the consequences of global warming aren’t explicitly baked into projections. Scientists say the region is likely to grow drier, with more frequent, intense droughts parching Central Texas.
Officials with the Environmental Defense Fund told the board that there is no indication that climate models were used systematically in developing regional water plans.
But state officials said the water plan gets updated every five years to fold in information from the latest droughts — such as the dire one that began in 2011 before finally ending this year.
“There are currently no forecasting tools capable of providing reliable estimates of changes to future water resources in Texas at the resolution needed for water planning,” water board spokeswoman Kimberly Leggett said.
The state “continues to collect data and work with regional planning groups to consider potential ways to improve estimates of water supply reliability in the face of drought. This includes monitoring climate policy and science,” Leggett said.