Runholt-Mellenthin Reservoir Report
Nearby: Lynd Twp 8 Lynd 9 & 16
Last Updated: December 13, 2025
Runholt-Mellenthin is a privately owned earth dam located in Lyon County, Minnesota, on the Redwood River.
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Summary
Constructed in 1958 by the USDA NRCS, this dam serves multiple purposes including fire protection, stock, and small fish pond management. With a height of 18 feet and a length of 340 feet, it has a storage capacity of 55 acre-feet and a drainage area of 0.5 square miles. The dam has a low hazard potential and a satisfactory condition assessment, last inspected in March 2017.
Managed by the Minnesota Department of Natural Resources, the Runholt-Mellenthin dam is regulated, permitted, inspected, and enforced by state agencies. It falls under the jurisdiction of the MNDNR EWR and the primary source agency is the state of Minnesota. The dam has uncontrolled spillways and outlet gates, with a maximum discharge of 140 cubic feet per second. The risk assessment for this dam is moderate, indicating potential hazards that require ongoing management and monitoring to ensure public safety and environmental protection.
In the event of an emergency, there are procedures in place to address potential risks associated with the dam. While the dam has not been modified in recent years, regular inspections every 8 years help assess its condition and identify any necessary maintenance or improvements. With its critical role in water resource management and protection, Runholt-Mellenthin serves as a vital infrastructure for the local community and ecosystem along the Redwood River in Minnesota.
Year Completed |
1958 |
Dam Length |
340 |
Dam Height |
16 |
River Or Stream |
REDWOOD RIVER-TR |
Primary Dam Type |
Earth |
Drainage Area |
0.5 |
Nid Storage |
55 |
Structural Height |
18 |
Outlet Gates |
Uncontrolled |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
18 |
Seasonal Comparison
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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.
Runholt-Mellenthin