Long Lake Flowage Wla Reservoir Report

Last Updated: December 5, 2025

Long Lake Flowage Wildlife Area, located in Sauk County, Wisconsin, is a state-managed water resource offering a variety of recreational opportunities.


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Summary

The earth dam, completed in 1972, stands at a height of 10 feet and spans 3050 feet, creating a reservoir with a storage capacity of 1000 acre-feet and a surface area of 150 acres. The primary purpose of the dam is for recreation, providing a serene and picturesque setting for visitors to enjoy water-based activities.

Maintained by the Wisconsin Department of Natural Resources, Long Lake Flowage WLA is regulated and inspected by state agencies to ensure its safety and functionality. The dam has a low hazard potential and is rated in fair condition, with regular inspections and maintenance efforts in place. Despite its low hazard potential, the area is considered to have a very high risk due to its location and potential impact in case of an emergency. Visitors can rest assured that emergency preparedness measures are in place to mitigate any risks associated with the dam.

For water resource and climate enthusiasts, Long Lake Flowage WLA offers a fascinating glimpse into the management and conservation of a vital natural resource. The controlled spillway and drainage area of 24 square miles contribute to the overall health of the ecosystem, while also providing recreational opportunities for visitors to enjoy. With its rich history and ongoing commitment to safety and conservation, Long Lake Flowage WLA stands as a testament to the importance of responsible water resource management in the face of changing climate conditions.

Year Completed

1972

Dam Length

3050

Dam Height

10

River Or Stream

LONG LAKE INLET

Primary Dam Type

Earth

Surface Area

150

Hydraulic Height

10

Drainage Area

24

Nid Storage

1000

Structural Height

10

Hazard Potential

Low

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.