Lake Travis is 63.75 miles long, and its maximum width is 4.5 miles. The lake covers 18,929 acres, and its capacity is 1,953,936 acre-feet. The lake is considered full at an elevation of 681.1 msl. At this elevation the lake contains 382,092,882,600 gallons of water. There are 270 miles of shoreline around the lake. It has a maximum depth of 210 and an average depth of 62 feet. The lakes historic high level is 710.4 feet msl on December 25, 1991. Its historic low level is 614.2 feet msl on August 14 1951.
Lake Travis was created by the impounding of the Colorado River by the construction of Mansfield Dam in 1937- 41. The dam is 266.41 feet high. The length is 7,089.39 feet. At the base it is 213 feet thick. Ranch Road 620 built on top of the dam and the adjoining protective walls bring the actual height of the dam to 274 feet. The top of the dam is 750 feet msl. Its spillway elevation is 714 feetmsl. At this elevation the lake contains 636,691,999,536 gallons of water. It has 3 Pen Stocks which divert water to 3 turbines with a total electrical generating capacity of 93,000 kw. The Dam has 24 floodgates at 4,770 cfs each. Each floodgate is 8.5 feet in diameter.