Lake levels rise with heavy May rain, but drought near the Highland Lakes is not over
Intense rain and flooding in late May led to higher lake levels and a significant increase in the combined storage of lakes Buchanan and Travis - LCRA's reservoirs that store water supply for the region.
But even with the record-setting rainfall, the lakes are not yet full, and the drought impacting the Highland Lakes has not ended.
"A wet month - even an extremely wet one like the May we just had - isn't enough to break this drought," said John Hofmann, LCRA executive vice president of Water. "The level of Lake Travis rose dramatically in May, but the lakes are still a long way from being full."
Lake Travis rose nearly 36 feet and Lake Buchanan rose more than 6 feet in May. Most of the increase came over Memorial Day weekend and the following week.
The amount of water in lakes Buchanan and Travis increased by more than 537,000 acre-feet in May, to 1,304,400 acre-feet on June 1. An acre-foot is 325,851 gallons.
May's considerable rainfall was an abrupt change from earlier in the year. For much of the multiyear drought, inflows - the amount of water flowing into the Highland Lakes from streams and tributaries - were historically low and only a fraction of average. May inflows totaled 400,000 acre-feet - about 195 percent of the May average - and were the 11th highest inflows for the month on record.
Inflows in May were higher than any of the previous four yearly totals.
"The amount of rain we received is a blessing, but everyone should continue to be mindful of their water use and use only what they need," Hofmann said. "There's no reason to go back to water-wasting habits. Conserving water should be a way of life. In terms of water supply, we shouldn't consider this drought over yet."
During the record 1947-1957 drought, flooding rains in 1952 caused Lake Travis to rise more than 56 feet in a day. The rain was not enough to end the drought, which continued for another five years.
"We know this area can flood in the middle of a drought," Hofmann said. "We're in a much better spot then we were over the last several years, but we would still like to see more rain to add water supplies to the lakes."
The severity of the current drought, which began in 2008, has reduced the amount of water LCRA can provide reliably each year through a repeat of the driest conditions on record by 100,000 acre-feet, to 500,000 acre-feet. The revised inventory estimate reduces the amount of water LCRA will have available for sale in the future, but does not impact existing contracts.
Six of the 10 lowest annual inflows on record have occurred during the current drought. Average annual inflows for 1942-2014 are 1,216,295 acre-feet.
- The lowest annual inflows occurred in 2011 with only 127,802 acre-feet, about 11 percent of the annual average.
- The second lowest inflows were 209,023 acre-feet - about 17 percent of the annual average - in 2014.
- The third lowest inflows were 215,138 acre-feet - about 18 percent of the annual average - in 2013.
- The fourth lowest inflows were 284,462 acre-feet - or about 23 percent of the annual average - in 2008.
- The seventh lowest inflows were 393,163 acre-feet - or about 32 percent of the annual average - in 2012.
- The 10th lowest inflows were 499,732 acre-feet - or about 41 percent of the annual average - in 2009.
The Highland Lakes are doing exactly what they were designed to do. The lakes capture water when it rains to ensure the region has a reliable water supply during times of drought. Lakes Travis and Buchanan provide drinking water to more than a million people and water to industries, businesses, the environment and, when enough water is available, agriculture in the lower Colorado River basin.
In order to preserve the water supply, LCRA - with permission from the state - cut off Highland Lakes water to most interruptible water customers in 2012, 2013 and 2014. In March, the Texas Commission on Environmental Quality (TCEQ) approved emergency drought relief again through June 18. LCRA submitted a request to TCEQ on June 5 to extend the emergency drought relief for an additional 120 days. On June 17, the TCEQ executive director granted LCRA's request to extend the emergency relief for the remainder of the 2015 irrigation season, and the Commission affirmed his decision on July 1.
LCRA also is increasing the water supply for the region by building the first new water supply reservoir in the lower Colorado River basin in decades. The
Lane City Reservoir is the first project that will allow LCRA to capture and store significant amounts of water downstream of the Highland Lakes. 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.