Prior Lake Reservoir Report

Last Updated: December 5, 2025

Prior Lake, also known as Lower Prior Lake, is a state-regulated water resource located in Scott County, Minnesota.


°F

°F

mph

Wind

%

Humidity

Summary

Managed by the Minnesota Department of Natural Resources, this concrete gravity dam serves primarily for recreation purposes, with a storage capacity of 1,760 acre-feet and a surface area of 1,056 acres. The dam, with a height of 12 feet and a length of 8 feet, is situated on the Minnesota River-TR stream.

Despite being classified with a low hazard potential, the dam at Prior Lake has not been rated for its condition assessment. The last inspection was conducted in June 2010, with a scheduled inspection frequency of every 8 years. The risk assessment for this structure is moderate, with a DSAC (Dam Safety Action Classification) score of 3. Emergency action plans, inundation maps, and risk management measures are currently not available for Prior Lake.

Enthusiasts of water resources and climate can appreciate the unique features of Prior Lake and the efforts put forth by state agencies to regulate and maintain the dam's safety. With its picturesque setting and recreational opportunities, Prior Lake serves as a vital resource for the community while also highlighting the importance of proper dam management and risk assessment in ensuring public safety and environmental preservation.

Dam Length

8

Dam Height

5

River Or Stream

MINNESOTA RIVER-TR

Primary Dam Type

Concrete

Surface Area

1056

Drainage Area

35

Nid Storage

1760

Structural Height

12

Outlet Gates

None

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.