Thompson Ditch Dam
Thompson Ditch Dam is an earth dam located in Vigo County, Indiana, built in 1977. It carries a High hazard potential classification and has a poor condition assessment.
About Thompson Ditch Dam
The primary purpose of Thompson Ditch 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 Terre Haute Sanitary District (local government). It impounds the Thompson Ditch.
The dam stands 33 feet tall and stretches 850 feet across, creates a reservoir covering 53 acres, has a maximum storage capacity of 1,170 acre-feet, and collects water from a drainage area of 3 square miles. Completed in 1977, the structure is 49 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 poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. Notably, no emergency action plan is currently on file for this high-hazard dam. The most recent inspection on record was 10/29/2018. That was 7 years ago, which is on the longer end for a high-hazard structure.
At 33 feet, this dam is taller than 78% of dams nationwide.
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 |
| River/Stream | Thompson Ditch |
| Coordinates | 39.44613, -87.35302 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 33 ft |
| Dam Height | 33 ft |
| Dam Length | 850 ft |
| Year Completed | 1977 (49 years old) |
Storage & Hydraulics
| NID Storage | 1,170 acre-ft |
| Max Storage | 1,170 acre-ft |
| Normal Storage | 860 acre-ft |
| Surface Area | 53 acres |
| Drainage Area | 3 sq mi |
| Max Discharge | 5,187 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | TERRE HAUTE SANITARY DISTRICT |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Poor |
| Last Inspection | 10/29/2018 |
| Emergency Action Plan | No |
Identifiers
| NID ID | IN00498 |
| Federal ID | IN00498 |
| More Info | State Dam Safety Program |