Water levels on Lake Travis are continuing to sink following July flooding, with a drought ongoing in the region as determined by the Lower Colorado River Authority.
What’s happening
Lake Buchanan is currently 95% full, at 1018.16 feet, according to a presentation shared by Shannon Hamilton, the Central Texas Water Coalition’s executive director, at an Oct. 6 Lakeway meeting. Lake Travis is 84% full at 671.17 feet.
Lake Travis’ water levels have dropped by 3-3.5 feet since July flooding. Despite the increased rainfall this year, the region remains in a drought that originally began in August 2019 and continues to today, Hamilton said.
Looking statewide, almost 40% of Texas is in an abnormally dry period, which could transition to a drought within the next few weeks if rain does not arrive soon, according to Hamilton’s presentation.
“Texas as a whole is experiencing a drought,” Hamilton said. “[But] we are in a much stronger drought than other areas."
The overview
Currently, the Lower Colorado River Authority is working on an updated Water Management Plan, which addresses how the Highland Lakes, including Lake Travis and Buchanan, are managed. The CTWC is currently reviewing materials provided by the LCRA associated with that update, and submitting comments and feedback, Hamilton said.
In the plan update, LCRA is accounting for 17% population growth in the region and increased water demands through 2032, Hamilton said.
Based on an independent water availability analysis run by the CTWC, the coalition is advocating for the LCRA to update its currently proposed plans by bumping the minimum storage capacity of the Highlands Lakes up from 600,000 acre-feet in volume to 675,000 acre-feet in order to ensure a reliable water supply.
When the volume drops to 600,000 acre-feet, a new drought of record is declared, Hamilton said. It also means that businesses’ water usage is curtailed by 20%.
What else?
Hamilton noted the importance of educating local residents on the difference between a meteorological drought and a hydrological drought.
According to the National Weather Service’s website, a meteorological drought is "is based on the degree of dryness or rainfall deficit and the length of the dry period,” whereas a hydrological drought is based on "the impact of rainfall deficits on the water supply such as stream flow, reservoir and lake levels, and ground water table decline.”
Although 20 inches of rain fell in July on the Highland Lakes, this did not improve groundwater conditions, Hamilton said, and aquifer levels remain unchanged.
“That was very surprising to me, and I think that goes to [show] the fact that we don’t have the historical science to really truly understand how aquifers replenish,” Hamilton said. “Continuing to protect our groundwater is just as important as ever.”
What’s next?
LCRA will respond to comments from their August meeting Oct. 10. Lakeway, the CTWC, the city of Austin and WCID No. 17 all submitted comments, Hamilton said.
“Everybody is in alignment [that] we need to raise the combined storage to 675 [thousand acre-feet] at a minimum,” Hamilton said. "LCRA’s last answer was no. ... But we’re still trying.”
