South Prong Dam
South Prong Dam is an earth dam located in Ellis County, Texas, built in 1956. It carries a High hazard potential classification.
About South Prong Dam
The primary purpose of South Prong Dam is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by Ellis County Wcid 1 (local government). It impounds the South Prong Waxahachie Creek.
The dam stands 62 feet tall and stretches 4,100 feet across, creates a reservoir covering 690 acres, has a maximum storage capacity of 22,764 acre-feet, and collects water from a drainage area of 29 square miles. Completed in 1956, the structure is well into its service life at over 50 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. An emergency action plan is in place for this dam. The most recent inspection on record was 11/13/2018. That was 7 years ago, which is on the longer end for a high-hazard structure.
At 62 feet, this dam is taller than 95% 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 | Ellis |
| River/Stream | South Prong Waxahachie Creek |
| Coordinates | 32.33772, -96.80289 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 62 ft |
| Dam Height | 62 ft |
| Dam Length | 4,100 ft |
| Year Completed | 1956 (70 years old) |
Storage & Hydraulics
| NID Storage | 22,764 acre-ft |
| Max Storage | 22,764 acre-ft |
| Normal Storage | 13,500 acre-ft |
| Surface Area | 690 acres |
| Drainage Area | 29 sq mi |
| Max Discharge | 105,443 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Water Supply |
| Owner | ELLIS COUNTY WCID 1 |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Not Rated |
| Last Inspection | 11/13/2018 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | TX01255 |
| Federal ID | TX01255 |
| More Info | State Dam Safety Program |