Water School

Periodically, officials conduct surveys of reservoirs within the Brazos River basin to determine each lake’s volume. As part of that work, survey crews determine each lake’s depth (in feet). Do not confuse this measurement with lake level, however.

A reservoir’s depth is the distance from the bottom to the top of the conservation pool, the point where the lake is considered full. The lake level is the number of feet the surface is above mean sea level.

Surveys use a combination of GPS technology and sonar to find the lake’s depth at various points to get an average to determine volume. The sonar sends sound waves to the lake bottom at different frequencies, and the results are compared to help also determine how much sediment has collected. The surveys also find each lake’s deepest point, which is typically near the dam.

The following lakes are in the Authority system: