Thompson Dam is an earth dam located in Lapeer County, Michigan, built in 1940. It carries a Low hazard potential classification and has a fair condition assessment.
Dam profile
NID height · 12 ft12 ft tall and 210 ft long. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.
About Thompson Dam
The primary purpose of Thompson Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Fox Hollow Holdings LLC (private). It impounds the Tributary to S Br Flint River near Thornville.
The dam stands 12 feet tall and stretches 210 feet across, creates a reservoir covering 9 acres, has a maximum storage capacity of 70 acre-feet, and collects water from a drainage area of 4 square miles. Completed in 1940, the structure is well-established, with more than 75 years of service.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. The most recent inspection on record was 07/08/2010. That was over 16 years ago.
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Location
| State | Michigan |
| County | Lapeer |
| Nearest City | Thornville |
| River/Stream | Tributary to S Br Flint River |
| Coordinates | 42.90223, -83.27613 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 12 ft |
| Dam Height | 12 ft |
| Dam Length | 210 ft |
| Year Completed | 1940 (86 years old) |
Storage & Hydraulics
| NID Storage | 70 acre-ft |
| Max Storage | 70 acre-ft |
| Normal Storage | 45 acre-ft |
| Surface Area | 9 acres |
| Drainage Area | 4 sq mi |
| Max Discharge | 80 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | Fox Hollow Holdings LLC |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Fair |
| Last Inspection | 07/08/2010 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | MI00301 |
| Federal ID | MI00301 |
| More Info | State Dam Safety Program |