The Texas Water Development Board (TWDB) will be performing an updated hydrographic survey of Possum Kingdom Lake to determine the volume of water that the reservoir currently holds. The Brazos River Authority contracts with TWDB to survey the reservoirs approximately once every 10 years in order to monitor sediment accumulation.
The survey, jointly funded by the BRA and a grant from the US Army Corps of Engineers, is being conducted by staff members of the Water Development Board’s Hydrographic Survey Program. The previous survey of Possum Kingdom Lake was performed in 2005.
Here’s how it works: Following a grid pattern from one end of the reservoir to the other, a boat sends out sonar signals to measure the depth of the water at numerous locations. Once that data is collected, the researchers develop what is essentially a topographic map of the lake bottom, which is used to calculate how much water the reservoir holds and how much surface area it covers at various depths. This can be compared with previous surveys to determine rates and location of sediment or silt accumulation.
The new survey will give a more up-to-date picture of the lake’s volume and help understand siltation rates for future water-supply planning.
The TWDB volumetric survey program began in the 1990s, and since that time, all BRA system reservoirs have been surveyed at least twice.
The survey team is expected to be on Possum Kingdom Lake for at least three weeks. For more information about volumetric surveys including previous surveys on Possum Kingdom Lake and other reservoirs statewide, please visit the TWDB’s website, here.