Lewis Reservoir Report

Last Updated: December 13, 2025

Located in Jackson, Wisconsin, the Lewis dam is a privately owned structure designed by the USDA NRCS for multiple purposes, including fire protection, stock, and recreation.


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Summary

Completed in 1967, this earth dam stands at a height of 14 feet and spans a length of 570 feet, with a storage capacity of 80 acre-feet. Situated on TR French Creek, the dam serves as a critical water resource in the area.

With a low hazard potential and fair condition assessment, the Lewis dam is regulated by the Wisconsin Department of Natural Resources, ensuring state permitting, inspection, and enforcement. Despite its moderate risk assessment rating, the dam has a controlled spillway and last underwent inspection in October 2018. As a vital component of the local water management infrastructure, the Lewis dam plays a significant role in maintaining water resources and protecting against potential flooding events in the region.

As water resource and climate enthusiasts, understanding the characteristics and maintenance of structures like the Lewis dam is crucial for ensuring the sustainable management of our natural resources. With its historical significance and ongoing regulatory oversight, the Lewis dam exemplifies the importance of proactive monitoring and risk management in safeguarding water sources and enhancing community resilience to environmental challenges.

Year Completed

1967

Dam Length

570

Dam Height

14

River Or Stream

TR FRENCH CREEK

Primary Dam Type

Earth

Surface Area

9

Hydraulic Height

10

Drainage Area

0.9

Nid Storage

80

Structural Height

14

Hazard Potential

Low

Nid Height

14
       
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.