New Lisbon Reservoir Report

Last Updated: December 15, 2025

New Lisbon is a gravity dam located on the Lemonweir River in Wisconsin, completed in 1938 primarily for recreation purposes.


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Summary

The dam stands at 18 feet high and is used to store water with a maximum storage capacity of 680 acre-feet. With a surface area of 60 acres and a drainage area of 507 square miles, New Lisbon also serves as a controlled spillway with a width of 114 feet, ensuring a maximum discharge of 9800 cubic feet per second.

Despite its low hazard potential and fair condition assessment, New Lisbon poses a very high risk due to its location and structural characteristics. The dam has undergone modifications in 1997 and is subject to regular inspections every 10 years. The surrounding area is at risk of inundation, which warrants the need for effective risk management measures and emergency action plans to ensure the safety of the community and the integrity of the dam in the face of potential climate-related challenges. With the St. Paul District overseeing its regulation and enforcement, New Lisbon stands as a key water resource infrastructure in Juneau, Wisconsin, amidst the backdrop of increasing climate variability.

Years Modified

1997 - Other

Year Completed

1938

Dam Length

120

Dam Height

18

River Or Stream

LEMONWEIR R

Primary Dam Type

Gravity

Surface Area

60

Hydraulic Height

6

Drainage Area

507

Nid Storage

680

Structural Height

18

Hazard Potential

Low

Nid Height

18
       
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.