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. It’s important to note lakes Travis and Buchanan are not constant-level lakes and are designed to fluctuate.
Inflows and lake level projections
Widespread rain over much of the Highland Lakes watershed in early September helped saturate the soil, raise lake levels slightly and ease drought conditions. The rain was a welcome change from a hot and dry summer.
In August, rainfall totals over parts of the watershed were near-normal, but little water flowed into the lakes as most of the rain soaked into parched soil. August inflows were 7,041 acre-feet, about 12 percent of the historic monthly average. In July, inflows were 2 percent of the monthly average; in June, inflows were 4 percent of the monthly average; and in May, inflows were 12 percent of the monthly average. Inflows are the amount of water flowing into the lakes estimated from measurements at four gauges upstream. (An acre-foot is 325,851 gallons.)
Inflows for January through August 2018 are the fourth lowest on record for that time period.
Here are LCRA's six-month projections for Lake Travis and Lake Buchanan based on conditions ranging from very wet to very dry.