Llewellyn Lake Dam
Llewellyn Lake Dam is an earth dam located in Vigo County, Indiana, built in 1966. It carries a High hazard potential classification.
About Llewellyn Lake Dam
The primary purpose of Llewellyn Lake 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 Ralph E. Llewellyn (private). It impounds the Tr-south Fork Lost Creek near Terre Haute.
The dam stands 20 feet tall and stretches 490 feet across, creates a reservoir covering 14 acres, and has a maximum storage capacity of 123 acre-feet. Completed in 1966, 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. Notably, no emergency action plan is currently on file for this high-hazard dam. The most recent inspection on record was 07/14/1992. That was 33 years ago — unusually long for a high-hazard dam, which typically requires more frequent inspections.
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 Indiana 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 | Indiana |
| County | Vigo |
| Nearest City | Terre Haute |
| River/Stream | Tr-south Fork Lost Creek |
| Coordinates | 39.46961, -87.31129 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 20 ft |
| Dam Height | 13 ft |
| Dam Length | 490 ft |
| Year Completed | 1966 (60 years old) |
Storage & Hydraulics
| NID Storage | 123 acre-ft |
| Max Storage | 123 acre-ft |
| Normal Storage | 70 acre-ft |
| Surface Area | 14 acres |
| Max Discharge | 597 cfs |
Ownership & Safety
| Purpose | Water Supply |
| Owner | RALPH E. LLEWELLYN |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Not Rated |
| Last Inspection | 07/14/1992 |
| Emergency Action Plan | No |
Identifiers
| NID ID | IN00506 |
| Federal ID | IN00506 |
| More Info | State Dam Safety Program |