Hayman Falls Reservoir Report

Last Updated: December 6, 2025

Hayman Falls, located in Shawano, Wisconsin, is a gravity dam completed in 1918 for recreational purposes along the Embarrass River.


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Summary

With a height of 17 feet and a hydraulic height of 14 feet, this dam provides a surface area of 80 acres and a maximum discharge of 6,000 cubic feet per second. The dam has a controlled spillway with a width of 97 feet, ensuring the safety and stability of the structure.

Although last inspected in 1995, with a low hazard potential and a very high risk assessment rating of 1, Hayman Falls remains a well-maintained and monitored structure. The dam has a normal storage capacity of 415 acre-feet and a total storage of 660 acre-feet, serving as a vital recreational resource for the community. Managed by the Wisconsin Department of Natural Resources, the dam is regulated, permitted, inspected, and enforced to ensure the safety of its surrounding area and the Embarrass River ecosystem.

Climate and water resource enthusiasts will appreciate Hayman Falls for its historical significance, engineering design, and environmental impact. As a key feature in the Detroit District of Wisconsin, this dam showcases the importance of sustainable water management practices and the preservation of natural habitats. With its serene location and recreational opportunities, Hayman Falls stands as a testament to the harmonious coexistence of human infrastructure and the natural world in the heart of Shawano County.

Year Completed

1918

Dam Length

200

Dam Height

17

River Or Stream

EMBARRASS

Primary Dam Type

Gravity

Surface Area

80

Hydraulic Height

14

Drainage Area

260

Nid Storage

660

Structural Height

17

Hazard Potential

Low

Nid Height

17
       
Seasonal Comparison

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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.