Leigh Lake Reservoir Report

Last Updated: December 8, 2025

Leigh Lake, located in Oconto, Wisconsin, is a gravity dam that was completed in 1935 for the primary purpose of recreation.


°F

°F

mph

Wind

%

Humidity

Summary

The dam stands at 21 feet in height with a hydraulic height of 13 feet and a structural height of 21 feet. It has a storage capacity of 2,720 acre-feet and a maximum discharge rate of 870 cubic feet per second. The dam spans 130 feet in length and covers a surface area of 231 acres, with a drainage area of 1.5 square miles.

This significant dam on Messenger Creek is under the jurisdiction of the Wisconsin Department of Natural Resources (WIDNR) and is regulated, inspected, and enforced by the state agency. The hazard potential of Leigh Lake is considered significant, with a fair condition assessment as of July 2018. The dam poses a moderate risk, with a risk assessment rating of 3. Emergency action plans have been prepared, although the last revision was in 2009, and the effectiveness of these plans meeting guidelines is not specified. Despite these potential risks, Leigh Lake remains a popular destination for water resource and climate enthusiasts seeking recreational opportunities in the area.

Year Completed

1935

Dam Length

130

Dam Height

21

River Or Stream

MESSENGER CREEK

Primary Dam Type

Gravity

Surface Area

231

Hydraulic Height

13

Drainage Area

1.5

Nid Storage

2720

Structural Height

21

Hazard Potential

Significant

Nid Height

21
       
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.