Ottumwa Dam
Ottumwa Dam is an earth dam located in Haakon County, South Dakota, built in 1938. It carries a Significant hazard potential classification.
About Ottumwa Dam
The primary purpose of Ottumwa Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by S&pl (state). It impounds the Mule Creek-tr.
The dam stands 26 feet tall and stretches 800 feet across, and has a maximum storage capacity of 1,000 acre-feet. Completed in 1938, the structure is well-established, with more than 75 years of service.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. The most recent inspection on record was 12/21/2023.
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Location
| State | South Dakota |
| County | Haakon |
| Nearest City | None |
| River/Stream | Mule Creek-tr |
| Coordinates | 44.24043, -101.34402 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 26 ft |
| Dam Height | 26 ft |
| Dam Length | 800 ft |
| Year Completed | 1938 (88 years old) |
Storage & Hydraulics
| NID Storage | 1,000 acre-ft |
| Max Storage | 1,000 acre-ft |
| Normal Storage | 152 acre-ft |
| Max Discharge | 2,300 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | S&PL |
| Owner Type | State |
| Hazard Classification | Significant |
| Last Inspection | 12/21/2023 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | SD00713 |
| Federal ID | SD00713 |
| More Info | State Dam Safety Program |