Wynne Lake Reservoir Report

Last Updated: December 5, 2025

Wynne Lake in Minnesota is a gravity dam located on the Embarrass River, with a structural height of 15 feet and a dam length of 119 feet.


°F

°F

mph

Wind

%

Humidity

Summary

Completed in 1944, this state-regulated dam serves a primary purpose of "Other" and has a normal storage capacity of 6,975 acre-feet. With a low hazard potential and satisfactory condition assessment, Wynne Lake is a vital water resource for the St. Louis County area, providing flood control and water supply management.

Managed by the Minnesota Department of Natural Resources, Wynne Lake is inspected every 8 years to ensure its continued safety and functionality. The dam has a drainage area of 145.5 square miles and a maximum discharge capacity of 7,105 cubic feet per second. In case of emergencies, the dam's emergency action plan (EAP) is designed to guide response efforts and protect downstream communities from potential risks associated with the dam's operation.

Climate enthusiasts will appreciate Wynne Lake's role in water resource management and its impact on the local ecosystem. As part of the St. Paul District of the US Army Corps of Engineers, this dam contributes to the overall water infrastructure in Minnesota, highlighting the importance of sustainable dam operations in mitigating climate-related challenges such as flooding and drought. With a focus on environmental stewardship and risk management, Wynne Lake exemplifies the intersection of water resource management and climate resilience in the region.

Year Completed

1944

Dam Length

119

Dam Height

12

River Or Stream

EMBARRASS RIVER

Primary Dam Type

Gravity

Hydraulic Height

5

Drainage Area

145.5

Nid Storage

7712

Structural Height

15

Hazard Potential

Low

Foundations

Unlisted/Unknown

Nid Height

15
       
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.