Hanson Reservoir Report

Last Updated: December 5, 2025

Hanson, located in Iron, Wisconsin, is a private earth dam built in 1972 by the USDA NRCS for fire protection, stock, or small fish pond purposes.


°F

°F

mph

Wind

%

Humidity

Summary

This dam stands at a height of 23 feet with a hydraulic height of 18 feet, providing a storage capacity of 110 acre-feet. The dam has a surface area of 9 acres and serves a drainage area of 0.1 square miles, with a maximum discharge capacity of 20 cubic feet per second.

Managed by the WIDNR, Hanson has a low hazard potential and is rated in fair condition as of the last assessment in May 2020. Despite being uncontrolled, the spillway is designed to handle overflow events safely. The dam underwent its last inspection in August 2017, with a scheduled inspection frequency of 10 years. While the risk assessment indicates a moderate level of risk, there are currently no specific risk management measures in place.

Located in a remote area with no associated structures or nearby city, Hanson serves as an essential water resource for the surrounding area for both agricultural and emergency purposes. With its strategic location along TR ALDER CREEK-NON NAV, this dam plays a crucial role in maintaining water supply and ensuring fire protection for the region. For water resource and climate enthusiasts, Hanson represents a unique example of sustainable water management practices in a rural setting.

Year Completed

1972

Dam Length

160

Dam Height

23

River Or Stream

TR ALDER CREEK-NON NAV

Primary Dam Type

Earth

Surface Area

9

Hydraulic Height

18

Drainage Area

0.1

Nid Storage

110

Structural Height

23

Hazard Potential

Low

Nid Height

23
       
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.