Upper San Marcos River Ws Scs Site 1
Upper San Marcos River Ws Scs Site 1 is an earth dam located in Hays County, Texas, built in 1983. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Upper San Marcos River Ws Scs Site 1
The primary purpose of Upper San Marcos River Ws Scs Site 1 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 San Marcos;hays County;hays County Swcd;upper San Marcos Ws Recl Fcd (local government). It impounds the Sink Creek near San Marcos.
The dam stands 80 feet tall and stretches 2,905 feet across, creates a reservoir covering 25 acres, has a maximum storage capacity of 18,399 acre-feet, and collects water from a drainage area of 33 square miles. Completed in 1983, the structure is 43 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 satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 10/13/2020.
At 80 feet, this dam is taller than 97% of all dams in the United States.
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 | Hays |
| Nearest City | San Marcos |
| River/Stream | Sink Creek |
| Coordinates | 29.91893, -97.97381 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 80 ft |
| Dam Height | 80 ft |
| Dam Length | 2,905 ft |
| Year Completed | 1983 (43 years old) |
Storage & Hydraulics
| NID Storage | 18,399 acre-ft |
| Max Storage | 18,399 acre-ft |
| Normal Storage | 304 acre-ft |
| Surface Area | 25 acres |
| Drainage Area | 33 sq mi |
| Max Discharge | 76,927 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | CITY OF SAN MARCOS;HAYS COUNTY;HAYS COUNTY SWCD;UPPER SAN MARCOS WS RECL FCD |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 10/13/2020 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | TX05945 |
| Federal ID | TX05945 |
| More Info | State Dam Safety Program |