Redwood River Reservoir Report
Nearby: Twp Road 73 Lake Marshall 19 & 30
Last Updated: December 13, 2025
The Redwood River, also known as Marshall Dam, is a vital water resource in Lyon, Minnesota, managed by the local government with regulatory oversight from the Minnesota Department of Natural Resources - Ecological and Water Resources Division.
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Summary
This gravity dam, completed in 1963 by the USCOE, serves the primary purpose of flood risk reduction for the surrounding area. With a height of 27 feet and a storage capacity of 450 acre-feet, the dam plays a crucial role in managing the flow of the river, which has a drainage area of 260 square miles.
Located in the city of Marshall, Minnesota, the Redwood River dam has a satisfactory condition assessment and a significant hazard potential, emphasizing the importance of regular inspections and maintenance. The last inspection in March 2017 revealed that the dam meets regulatory guidelines, but ongoing risk management measures are necessary to address moderate risk levels. The dam does not have associated locks or spillway controls, with a spillway width of zero, highlighting the need for careful monitoring of water levels and discharge rates during periods of high flow.
For water resource and climate enthusiasts, the Redwood River dam presents a fascinating case study in flood risk reduction and water management. As a critical infrastructure project with a long history of service to the community, this dam exemplifies the need for proactive monitoring and maintenance to ensure its continued effectiveness in protecting lives and property from flooding events. The collaboration between local government, state agencies, and the USCOE underscores the importance of multi-level cooperation in safeguarding water resources for future generations.
Year Completed |
1963 |
Dam Length |
75 |
Dam Height |
27 |
River Or Stream |
REDWOOD RIVER |
Primary Dam Type |
Gravity |
Drainage Area |
260 |
Nid Storage |
450 |
Structural Height |
32 |
Hazard Potential |
Significant |
Foundations |
Unlisted/Unknown |
Nid Height |
32 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Dam Data Reference
Condition Assessment
SatisfactoryNo existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
Poor A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency. Investigations and studies are necessary.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Not Available
Dams for which the condition assessment is restricted to approved government users.
Hazard Potential Classification
HighDams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.
Redwood River