Mantorville Reservoir Report
Nearby: Donaldson Pond Buehler Detention
Last Updated: December 6, 2025
Mantorville is a historic gravity dam located on the Zumbro River in Dodge County, Minnesota.
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Summary
Completed in 1888, the dam serves primarily for recreational purposes, offering a surface area of 2 acres and a drainage area of 147.7 square miles. With a dam height of 12 feet and a length of 565 feet, Mantorville provides a maximum storage capacity of 436 acre-feet and a normal storage of 238 acre-feet.
Managed by the Minnesota Department of Natural Resources, Mantorville is regulated, permitted, inspected, and enforced by state agencies to ensure its safety and functionality. The dam has a low hazard potential and is assessed to be in fair condition as of the last inspection in 2017. While the spillway type is uncontrolled, the dam has a moderate risk assessment rating of 3, indicating the need for proactive risk management measures to mitigate potential hazards and ensure the dam's long-term resilience in the face of changing climate conditions.
Water resource and climate enthusiasts will find Mantorville to be a significant landmark in the region, showcasing the intersection of historical engineering with modern-day environmental stewardship. As a key component of the local ecosystem and recreational infrastructure, Mantorville exemplifies the importance of sustainable water management practices in the face of evolving climate challenges. Its maintenance and operation reflect a commitment to ensuring the safety and resilience of water resources for both present and future generations.
Year Completed |
1888 |
Dam Length |
565 |
Dam Height |
12 |
River Or Stream |
ZUMBRO RIV S BR MIDDLE FK |
Primary Dam Type |
Gravity |
Surface Area |
2 |
Drainage Area |
147.7 |
Nid Storage |
436 |
Structural Height |
13 |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
13 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
South Fork Zumbro River At Rochester
|
85cfs |
Straight River Near Faribault
|
83cfs |
Cedar River Near Austin
|
110cfs |
Cannon River At Welch
|
384cfs |
Mississippi River At Red Wing
|
12400cfs |
Root River Near Pilot Mound
|
303cfs |
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.
Mantorville
Diamond Ridge
Judd Park
Arbor Glen Park