Lake Calhoun Diversion Reservoir Report

Last Updated: December 12, 2025

Lake Calhoun Diversion, located in Crow River, Minnesota, is a gravity dam completed in 1937 with a height of 10 feet and a hydraulic height of 4.4 feet.


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Summary

The dam serves as a crucial structure for water resource management, with a normal storage capacity of 75 acre-feet and a maximum storage of 90 acre-feet. With a drainage area of 151.6 square miles, the dam plays a significant role in regulating water flow and ensuring downstream water availability.

Managed by the Minnesota Department of Natural Resources, Lake Calhoun Diversion is state-regulated and undergoes regular inspections to maintain its fair condition and low hazard potential. The dam primarily serves "Other" purposes and is designed as a buttress gravity dam, spanning 18 feet in length and covering a surface area of 617 acres. Despite its age, the dam continues to efficiently contribute to flood control measures and water storage in the region, highlighting its importance in the overall water resource infrastructure.

With its historical significance and ongoing operational relevance, Lake Calhoun Diversion stands as a testament to effective water management practices in Minnesota. The dam's presence on the Crow River Middle Fork not only ensures water availability for various stakeholders but also showcases the state's commitment to maintaining critical infrastructure for climate resilience. As climate change impacts continue to challenge water resources, Lake Calhoun Diversion remains a vital component in safeguarding the region's water security and adaptation efforts.

Year Completed

1937

Dam Length

18

Dam Height

10

River Or Stream

CROW RIVER MIDDLE FORK

Primary Dam Type

Gravity

Surface Area

617

Hydraulic Height

4.4

Drainage Area

151.6

Nid Storage

90

Structural Height

12

Hazard Potential

Low

Foundations

Unlisted/Unknown

Nid Height

12
       
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.