Olmos Dam

The Olmos Dam is a flood control dam located on the Olmos Creek in San Antonio, Texas. Constructed between 1926 and 1929 following the devastating 1921 flood, its primary purpose is to protect the city of San Antonio from the destructive power of flash floods along the Olmos Basin. The dam works by temporarily impounding floodwaters during periods of heavy rainfall, slowly releasing them downstream into the San Antonio River in a controlled manner, thereby reducing the risk of widespread flooding in the urban areas.

The dam is an earthfill embankment dam, meaning it is primarily constructed from compacted soil. It stretches approximately 1,940 feet in length and has a maximum height of around 65 feet. The dam's spillway allows excess water to safely bypass the dam during extreme rainfall events when the reservoir's storage capacity is exceeded.

While its main function is flood control, the area surrounding the Olmos Dam has also evolved into a popular recreational area, with trails and green spaces utilized by the public for hiking, biking, and other outdoor activities. The dam and its surrounding parkland are managed by the San Antonio River Authority.