The Highland Lakes were created to manage floods and capture water when it rains to ensure the region has a reliable water supply during dry times. Lakes Buchanan and Travis – the region's water supply reservoirs – provide water for more than a million users, including communities, industries, businesses, agriculture and the environment in the lower Colorado River basin. Together, lakes Buchanan and Travis can hold about 2 million acre-feet of water, and they currently are nearly three-fourths full. It's important to note lakes Travis and Buchanan are not constant-level lakes and are designed to fluctuate, as they are now.
Lake level projections
LCRA projections show that without additional rain, levels in Lake Travis and Lake Buchanan will fall as temperatures remain hot and water use remains high over the next few months. In July, rainfall totals over most of the Highland Lakes watershed in the Hill Country were 1 to 2 inches below normal, and little water flowed into the lakes. As often happens during dry times, most of the rain soaked into parched soil and did not run off to fill the streams and rivers that replenish the lakes.
At 1,726 acre-feet, inflows into the lakes in July were about 2 percent of the historic monthly average, continuing a year of low inflows. In June, for instance, inflows were 4 percent of the monthly average and in May, inflows were 12 percent of the monthly average. Inflows for January through July 2018 are the third lowest on record for that time period. Inflows are the amount of water flowing into the lakes estimated from measurements at four gauges upstream. (An acre-foot is 325,851 gallons.)