Perch Lake Reservoir Report
Nearby: Cottonwood Lake Rice Lake
Last Updated: December 6, 2025
Perch Lake, located in Blue Earth, Minnesota, is a state-regulated water resource with a low hazard potential and a satisfactory condition assessment.
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Summary
This earth dam, completed in 1973, has a height of 8 feet and a storage capacity of 2844 acre-feet, with a normal storage level of 555 acre-feet. The lake covers a surface area of 310 acres and serves as a vital water source for the surrounding area.
Managed by the Minnesota Department of Natural Resources, Perch Lake plays a crucial role in maintaining water levels and regulating the flow of the Cobb River-TR. With a maximum discharge of 25 cubic feet per second, this dam serves multiple purposes beyond flood control, making it a versatile structure that benefits both the environment and local communities. Despite being last inspected in 2018, the dam's condition remains satisfactory, ensuring its continued effectiveness in water resource management.
For water resource and climate enthusiasts, Perch Lake presents an intriguing case study in dam infrastructure and its impact on regional water systems. As a key component of Minnesota's water management strategy, this earth dam provides valuable insights into the intersection of environmental stewardship, regulatory compliance, and community resilience in the face of changing climate conditions. By understanding the history and function of Perch Lake, enthusiasts can gain a deeper appreciation for the complex dynamics at play in ensuring the sustainable use of our water resources.
Year Completed |
1973 |
Dam Length |
3 |
Dam Height |
8 |
River Or Stream |
COBB RIVER-TR |
Primary Dam Type |
Earth |
Surface Area |
310 |
Hydraulic Height |
2 |
Drainage Area |
2 |
Nid Storage |
2844 |
Structural Height |
8 |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
8 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Le Sueur River Near Rapidan
|
179cfs |
Blue Earth River Near Rapidan
|
328cfs |
Minnesota River At Mankato
|
2870cfs |
Watonwan River Near Garden City
|
82cfs |
Little Cottonwood River Near Courtland
|
33cfs |
Cottonwood River Near New Ulm
|
215cfs |
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.
Perch Lake