AUSTIN –LCRA forecasts that Colorado River streamflows downstream of Austin will continue at higher-than-normal levels until early September as Lake Travis is slowly lowered to at or below its flood pool. Additional rainfall in the Hill Country could extend that timetable.

After heavy rains starting Aug. 17 following Tropical Storm Erin, Lake Travis crested on Sunday, Aug. 19 and is slowly falling on Aug. 20 with an elevation at 686 feet above mean sea level (msl); the lake is considered full at 681 feel msl. To pass the floodwaters from Lake Travis, LCRA is operating hydroelectric-generating units at Mansfield Dam to release about 5,000 cubic feet of water per second.

“What they are seeing right now is what they are going to keep seeing for the next two weeks — if it doesn’t rain anymore,” said Dan Yates, an engineer in LCRA’s River Operations Center.

No locations along the river are expected to reach bank-full stage or flood stage based on current operations.

Lake Travis, which was specifically built to contain floodwaters until they can be safely released downstream, is operated based on rules from the U.S. Army Corps of Engineers that consider both forecasted Lake Travis levels and river levels at locations downstream of Austin. This time of year, the operating rules limit LCRA from stepping up water releases — for example, by opening one or more of the dam's 24 floodgates — until the lake is forecast to reach 691 feet msl. From Sept. 1 to Nov. 1, the threshold falls to 685 feet msl, allowing LCRA to open floodgates to release up to 30,000 cfs of water during those months.

For more information on dam operations and lake and river conditions, see Situation Report.