Mud Lake Reservoir Report

Last Updated: December 13, 2025

Mud Lake, located in Renville, Minnesota, is a dam structure owned by the local government that serves multiple purposes, including flood control and water storage.


°F

°F

mph

Wind

%

Humidity

Summary

Completed in 1986, this buttress-type dam stands at a height of 10 feet and has a storage capacity of 600 acre-feet. The dam spans 110 feet in length and is situated on the Little Rock Creek, contributing to the drainage area of 7 square miles.

While Mud Lake has a low hazard potential and is currently rated as "Not Rated" in terms of condition assessment, it is regulated by the Minnesota Department of Natural Resources, with state permitting, inspection, and enforcement mechanisms in place to ensure its safe operation. The dam's spillway is uncontrolled, with a hydraulic height of 3 feet and a structural height of 10 feet. The risk assessment for Mud Lake is classified as moderate, indicating a need for ongoing monitoring and risk management measures to safeguard against potential issues.

Overall, Mud Lake provides a valuable resource for water management in the region, contributing to flood protection and water storage capabilities. Its location in New Ulm and its association with the St. Paul District of the US Army Corps of Engineers underscore its importance in the local water infrastructure. With state oversight and regular inspections in place, Mud Lake continues to play a crucial role in maintaining water resources and climate resilience in the area.

Year Completed

1986

Dam Length

110

Dam Height

7

River Or Stream

LITTLE ROCK CREEK

Primary Dam Type

Other

Surface Area

168

Hydraulic Height

3

Drainage Area

7

Nid Storage

600

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.