Olmos Dam

OLMOS CREEK· Bexar, Texas· Built 1926· Gravity· 58 ft tall
High Hazard Flood Risk Reduction Local Government

Key Takeaway

Olmos Dam is classified as high hazard in Texas. It was completed in 1926 and is 100 years old. Its primary use is flood risk reduction. High hazard means loss of life is likely if the dam fails — it does not indicate the dam's current condition. Learn more.

Physical Details

Dam Height 58 ft (taller than 96.5% in TX)
Dam Length1,941 ft
Dam TypeGravity
Max Storage22.0K acre-ft
Normal Storage15.6K acre-ft
Surface Area0 acres
Drainage Area32 sq mi
Max Discharge74,326 cfs
Year Completed1926 (100 years old)
NID IDTX04313

Safety Information

High Hazard

Loss of human life is likely if the dam fails.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: Yes
Last Inspection: March 8, 2018
State Regulated: Yes
Regulatory Agency: TCEQ

Ownership

CITY OF SAN ANTONIO

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Olmos Dam?

Olmos Dam is classified as High Hazard. Loss of human life is likely if the dam fails. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Olmos Dam?

Olmos Dam is owned by CITY OF SAN ANTONIO (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Olmos Dam built?

Olmos Dam was completed in 1926, making it 100 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.

What is the primary purpose of Olmos Dam?

Olmos Dam serves the following purposes: Flood Risk Reduction. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Olmos Dam?

Olmos Dam has a dam height of 58 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.

When was Olmos Dam last inspected?

Olmos Dam was last inspected on March 8, 2018. Inspection dates indicate when a formal review occurred, not the results of that inspection.

Data from the National Inventory of Dams (NID) maintained by the US Army Corps of Engineers. Dam conditions may have changed since the last update. This site is not affiliated with USACE. Do not use for emergency planning — contact your local dam safety program.