A wet 2015 ends with lake levels above average
Heavy rain across the Highland Lakes watershed in 2015 translated into dramatic rises on lakes Travis and Buchanan, which are starting 2016 substantially higher than they have been in years.
In contrast to the severe drought that gripped the region for the last few years, 2015 was very wet across the entire lower Colorado River basin. The Texas Hill Country, including the watershed that feeds the Highland Lakes, received 30-35 inches of rain. Central Texas saw rainfall totals reach 40-50 inches. The coastal plains saw 50-60 inches of rain.
Lake Travis rose more than 53 feet in 2015, while Lake Buchanan rose more than 25 feet. As of Jan. 1, 2016, lakes Buchanan and Travis – the region's water supply reservoirs – together stood at 87 percent of capacity.
"A year ago, lakes Buchanan and Travis were just 34 percent of capacity," said John Hofmann, LCRA executive vice president of Water. "We saw a big increases after rains in May and July, then again when El Niño's influence on our weather pattern kicked in during the fall. The boost to lake levels from wet weather in December was a great way to end the year. El Niño may not be through with us yet, so we could see additional wet weather this winter and spring."
As of early January, Lake Travis was about 10 feet above average, and Lake Buchanan was almost 2 feet above average. The last time combined storage was this high in early January was 2008.
The amount of water flowing into the Highland Lakes in 2015 was about 81 percent of the average yearly inflows. As in May and July, inflows into the Highland Lakes in December were above average. December inflows totaled 93,862 acre-feet, about 138 percent of the monthly average. 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.
In 2016, LCRA will manage lakes Travis and Buchanan under a new state-approved Water Management Plan. In November 2015, the Texas Commission on Environmental Quality approved the updated plan, which 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.
The Highland Lakes also were built to help manage flooding along the Colorado River. During floods, LCRA operates the Highland Lakes dams to reduce flooding impacts on communities downstream of the lakes. Lake Travis is the only lake in the Highland Lakes chain specifically built to hold floodwaters. Even when considered full for water supply, Lake Travis can store an additional 787,000 acre-feet of water in what is referred to as the flood pool.