Currently available at: https://lake-travis-water-levels.herokuapp.com/lakedata
Use that, or deploy your own:
Sample Response:
{
"currentDepth": 668.42,
"fullVolume": 1134956,
"maxVolume": 1216672.8320000002,
"currentVolume": 912406,
"timestamp": "Sun Jun 07 2015 23:54:43 GMT+0000 (UTC)"
}
Provided without warranty by @tgrochowicz, with support by @rgrochowicz.