South Mopac Dam
South Mopac Dam is an earth dam located in Travis County, Texas, built in 1998. It carries a High hazard potential classification and has a fair condition assessment.
About South Mopac Dam
The primary purpose of South Mopac Dam is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by City Of Austin (local government). It impounds the Tr-slaughter Creek.
The dam stands 18 feet tall and stretches 1,600 feet across, has a maximum storage capacity of 283 acre-feet, and collects water from a drainage area of 4 square miles. Completed in 1998, the structure is 28 years old.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 07/22/2021.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Texas dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Texas |
| County | Travis |
| River/Stream | Tr-slaughter Creek |
| Coordinates | 30.17692, -97.87945 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 18 ft |
| Dam Height | 18 ft |
| Dam Length | 1,600 ft |
| Year Completed | 1998 (28 years old) |
Storage & Hydraulics
| NID Storage | 283 acre-ft |
| Max Storage | 283 acre-ft |
| Drainage Area | 4 sq mi |
| Max Discharge | 9,460 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | CITY OF AUSTIN |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Fair |
| Last Inspection | 07/22/2021 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | TX06509 |
| Federal ID | TX06509 |
| More Info | State Dam Safety Program |