Redwood River is a gravity dam located in Lyon County, Minnesota, built in 1963. It carries a Significant hazard potential classification and has a satisfactory condition assessment.
Dam profile
NID height · 32 ft32 ft tall and 75 ft long, taller than 74% of U.S. dams with a recorded height. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic concrete gravity section and the water level is illustrative.
About Redwood River
The primary purpose of Redwood River 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 City of Marshall (local government). It impounds the Redwood River near Marshall.
The dam stands 32 feet tall and stretches 75 feet across, has a maximum storage capacity of 450 acre-feet, and collects water from a drainage area of 260 square miles. Completed in 1963, the structure is well into its service life at over 50 years old.
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. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. The most recent inspection on record was 05/19/2021.
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Location
| State | Minnesota |
| County | Lyon |
| Nearest City | Marshall |
| River/Stream | Redwood River |
| Coordinates | 44.43787, -95.81379 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 32 ft |
| Dam Height | 27 ft |
| Dam Length | 75 ft |
| Year Completed | 1963 (63 years old) |
Storage & Hydraulics
| NID Storage | 450 acre-ft |
| Max Storage | 450 acre-ft |
| Normal Storage | 300 acre-ft |
| Drainage Area | 260 sq mi |
| Max Discharge | 7,900 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | City of Marshall |
| Owner Type | Local Government |
| Hazard Classification | Significant |
| Condition Assessment | Satisfactory |
| Last Inspection | 05/19/2021 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | MN00072 |
| Federal ID | MN00072 |
| More Info | State Dam Safety Program |