Navarino Marsh - 80 Ac Flowag Reservoir Report

Last Updated: December 6, 2025

Navarino Marsh, also known as the 80 Ac Flowage, is a state-owned water resource located in Shawano, Wisconsin.


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Summary

This 80-acre flowage is regulated by the Wisconsin Department of Natural Resources and boasts a controlled spillway with a width of 100 feet. With a maximum discharge capacity of 110 cubic feet per second, Navarino Marsh serves as a vital resource for managing water levels and supporting the surrounding ecosystem.

The dam at Navarino Marsh stands at a height of 7 feet and has a storage capacity of 400 acre-feet. The flowage covers an area of 175 acres and has a drainage area of 1.5 square miles. Although classified as having a low hazard potential, the risk assessment for this water resource indicates a very high risk level. Despite not having a current condition rating, Navarino Marsh plays a crucial role in water management and flood control in the region.

Located in the Detroit District, Navarino Marsh is situated in a picturesque setting in the city of Shiocton. While the last inspection of the flowage took place in July 2011, its emergency action plan status and risk management measures are not currently updated. As a significant water resource in Wisconsin, Navarino Marsh provides valuable insights and opportunities for water resource and climate enthusiasts interested in sustainable water management practices and the impact of climate change on freshwater ecosystems.

Dam Length

800

Dam Height

7

Surface Area

175

Hydraulic Height

7

Drainage Area

1.5

Nid Storage

400

Structural Height

7

Hazard Potential

Low

Nid Height

7
       
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.