Lake Travis is considered "full" (at maximum desired capacity) when the lake's water level is at above mean sea level (msl). Above , flood control gates at
Mansfield Dam are opened under the direction of the U.S. Army Corps of Engineers. The level of the lake can vary dramatically—with an over 96-foot range between its historical high and low—depending on the amount of rainfall in the Colorado River basin upstream. The historic high level on the lake was above msl on December 25, 1991, a little less than four feet below the dam's top/spillway at above msl. The historic low was above msl on August 14, 1951.
Droughts The extreme drought of 2008–2009 brought the lake to its fourth lowest level at above msl in November 2009. The second lowest level was above msl on November 8, 1963. During the
2010–13 Southern United States drought, levels went as low as 618 feet, making it the third lowest level ever. The
LCRA, a public utility whose responsibilities include the management of Lake Travis, makes water level reports available on the internet. In April 2016, the lake returned to its full capacity at 681 ft.
Floods Lake Travis serves as the primary
flood control reservoir of the Highland Lake chain. The LCRA, under advisement from the U.S. Army Corps of Engineers, is responsible for floodgate operations at Mansfield Dam. Ideally, this is done in a time-delayed fashion after a major rainfall so as to either mitigate or outright prevent downstream flooding which otherwise would have been both immediate and extreme without the dam's presence. As Lake Travis levels increase during major floods, floodgate operations are conducted to protect property around Lake Travis as well as the dam itself. While the dam's physical design assists in its own protection during floods, extensive spillway operations, a worst-case scenario which has not happened in the lake's history, could undermine the dam's base and affect its overall integrity. Under such conditions, operations are primarily intended to protect the dam, and lake water may be released to the dam's full, 24-floodgate capacity—regardless of downstream effects—to prevent the catastrophic loss of the dam. Including its hydroelectric generators but not the spillway, at 681 feet above msl the dam's total maximum discharge capacity is more than 130,000 cubic feet per second (cfs); a bit under one million gallons per second. Rates of discharge increase as water levels/pressures increase.
2025 flood impact and reopening In July 2025, Lake Travis was affected by severe flooding following heavy storms over the July 4 weekend in Central Texas. On July 11, Travis County Judge Andy Brown issued an executive order temporarily closing the entire lake to recreational, commercial, and navigational activities. The closure cited safety concerns due to submerged debris, damaged buoys, unsafe roads, and elevated bacteria levels. The county updated the order on July 13, reopening most of the lake to boating and other recreational activities, with the exception of Sandy Creek Park and the area upstream of mile marker 36, which remained closed due to ongoing hazards. Officials advised boaters to take safety precautions, including avoiding nighttime travel, swimming only in visible areas, and maintaining low speeds. Violators of the remaining restrictions could face Class C misdemeanor charges, including fines of up to $1,000 or six months in jail. Travis County officials credited the reopening to the ongoing cleanup and recovery efforts by county staff, volunteers, and partner agencies. As of July 20, 2025, Lake Travis was reported to be 90.0% full, following significant rainfall and inflows earlier in the month. The lake reopened fully on July 24th for all recreation, without any restrictions. == See also ==