Granger Dam
Granger Dam is an earth dam located in Williamson County, Texas, built in 1979. It carries a High hazard potential classification.
About Granger Dam
The primary purpose of Granger 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 Usace - Fort Worth District (federal). It impounds the San Gabriel River near Laneport.
The dam stands 115 feet tall and stretches 15,240 feet across, creates a reservoir covering 4,400 acres, has a maximum storage capacity of 650,000 acre-feet, and collects water from a drainage area of 475 square miles. Completed in 1979, the structure is 47 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 05/18/2022.
At 115 feet, this dam is taller than 98% 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 | Williamson |
| Nearest City | Laneport |
| River/Stream | San Gabriel River |
| Coordinates | 30.70148, -97.32984 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 115 ft |
| Dam Height | 115 ft |
| Dam Length | 15,240 ft |
| Year Completed | 1979 (47 years old) |
Storage & Hydraulics
| NID Storage | 650,000 acre-ft |
| Max Storage | 650,000 acre-ft |
| Normal Storage | 65,500 acre-ft |
| Surface Area | 4,400 acres |
| Drainage Area | 475 sq mi |
| Max Discharge | 342,330 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Water Supply |
| Owner | USACE - Fort Worth District |
| Owner Type | Federal |
| Hazard Classification | High |
| Condition Assessment | Not Available |
| Last Inspection | 05/18/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | TX08005 |
| Federal ID | TX08005 |
| More Info | State Dam Safety Program |