Central Texas storms in late October added more than 134,000 acre-feet to the combined storage in the Highland Lakes, moving lakes Travis and Buchanan near their highest levels since the flooding Memorial Day weekend rains.
Although much of the October rain fell downstream of the Highland Lakes, Lake Travis still rose more than 5 feet, while Lake Buchanan rose more than 2 feet from late October through early November.
“This year has been one of extremes,” said John Hofmann, LCRA executive vice president of Water. “We had extremely low inflows the first part of the year, then record rainfall over the Memorial Day weekend. We were concerned about a return to the dry weather pattern after those rains, and that’s exactly what happened. We had a drier-than-normal summer, then over two rainy weekends in October we gained a significant amount of water in the lakes. We’re hopeful we’ll see more rain in the near future – although we would prefer not to have any more damaging flood events.
“The lakes are in much better shape than they were earlier this year,’’ Hofmann said. “In addition, we are moving into the time of year when water use declines, and we don’t lose as much water to evaporation.”
October inflows to the Highland Lakes totaled 41,702 acre-feet – about 35 percent of the monthly average. The inflows don’t take into account rain that falls directly over the lakes. Inflows are the amount of water flowing into the Highland Lakes estimated from measurements at four gauges upstream of the lakes. An acre-foot of water is 325,851 gallons.
The Highland Lakes capture water when it rains to ensure the region has a reliable water supply during dry times. Lakes Travis and Buchanan provide drinking water for more than a million people and water to industries, businesses, the environment and agriculture in the lower Colorado River basin.
Lake levels have risen dramatically since the beginning of 2015. As of Nov. 5, Lake Travis was more than 47 feet higher than on Jan. 1, while Lake Buchanan was about 21 feet higher.
LCRA manages lakes Travis and Buchanan under a state-approved Water Management Plan. The Texas Commission on Environmental Quality approved an updated plan on Nov. 4. The updated plan better protects the water supply for firm customers – mainly cities and industrial users – and enables LCRA to more quickly adapt its operations as drought conditions change.
LCRA is committed to increasing the water supply for the region and is building the first significant new water supply reservoir in the lower Colorado River basin in decades. The Lane City Reservoir is the first project that will enable LCRA to capture and store significant amounts of water downstream of the Highland Lakes near the Texas Gulf Coast. The reservoir could add up to 90,000 acre-feet per year to LCRA’s water inventory and is expected to be completed in 2018. The new reservoir will help reduce the amount of water that otherwise would be required to be released from the Highland Lakes.
LCRA also is exploring integrated water strategies for Central Texas, including using surface water, treated effluent and groundwater.