Little Willow River Reservoir Report

Last Updated: December 5, 2025

The Little Willow River in Minnesota is a state-regulated body of water known for its important role in supporting fish and wildlife.


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Summary

Built in 1977 by the Minnesota Department of Natural Resources, this dam serves as a fish and wildlife pond with a storage capacity of 100 acre-feet and a normal storage of 10 acre-feet. The dam stands at a height of 10 feet and stretches 56 feet in length, providing a habitat for various species in the area.

Located in Aitkin County, the Little Willow River dam has a low hazard potential and is classified as satisfactory in condition assessment. With a moderate risk level, the dam is inspected every 8 years to ensure its safety and functionality. The surrounding area boasts a drainage area of 20 square miles and a surface area of 5 acres, making it a vital resource for water conservation and management in the region.

Although the dam has an uncontrolled spillway type, it has been designed with buttress core types to withstand potential risks. With a focus on fish and wildlife preservation, the Little Willow River dam is a crucial water resource for climate enthusiasts and conservationists looking to protect and sustain the ecological balance of the area.

Year Completed

1977

Dam Length

56

Dam Height

6

River Or Stream

LITTLE WILLOW RIVER

Primary Dam Type

Other

Surface Area

5

Drainage Area

20

Nid Storage

100

Structural Height

10

Hazard Potential

Low

Foundations

Unlisted/Unknown

Nid Height

10
       
Seasonal Comparison

Weather Forecast

Dam Data Reference

Condition Assessment

Satisfactory
No 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

High
Dams 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.