Olmos Reservoir

The Olmos Reservoir is on Olmos Creek in the San Antonio River basin four miles north of downtown San Antonio in central Bexar County (at 29°28' N, 98°28' W). The project is owned and operated by the city of San Antonio for flood protection of the downtown area. The reservoir was constructed after the record flood of September 1921, which extensively damaged the San Antonio business district. Construction on the dam was started in 1925 and completed in 1926. The reservoir has a capacity of 15,500 acre-feet and a surface area of 1,050 acres at the top of the dam, which is 728 feet above mean sea level. The reservoir basin is normally empty, and the area is used for parks, playgrounds, and a golf course, except when needed for floodwater storage. The drainage area above the dam is thirty-two square miles. The surrounding terrain is flat to gently rolling and is surfaced by clay loam soils that support mesquite, cacti, and grasses.

Adapted from the official Handbook of Texas, a state encyclopedia developed by the Texas State Historical Association (TSHA). It is an authoritative source of trusted historical records.

Lake Measurements

Surface Area (in acres)
Storage Capacity (in acre-feet)

Belongs to

Olmos Reservoir is part of or belongs to the following places.

Lake Maintained or Owned by

San Antonio River Authority

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Date of Origin

1926 97 years ago

Currently Exists


Place type

Olmos Reservoir is classified as a Lake


  • Municipal water supply

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