Hebron Reservoir Report

Last Updated: December 5, 2025

Hebron is a privately owned dam located in Jefferson, Wisconsin, along the Bark River.


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Summary

Built in 1933, this gravity dam serves primarily for recreational purposes, offering a surface area of 28 acres and a maximum storage capacity of 160 acre-feet. With a height of 17 feet and a hydraulic height of 11 feet, Hebron has a controlled spillway that is 65 feet wide, capable of handling a maximum discharge of 1520 cubic feet per second. Despite its age, the dam's hazard potential is rated as high, with a very high risk assessment due to its condition being not rated.

Managed by the Wisconsin Department of Natural Resources (WIDNR), Hebron is subject to state regulation, permitting, inspection, and enforcement. While the dam has not been assessed for its current condition, it is inspected biennially as a precautionary measure. The surrounding area has a drainage area of 163.5 square miles, making Hebron an important structure in managing water resources in the region. Its location within Congressional District 05 of Wisconsin adds to its significance in the local water infrastructure.

For water resource and climate enthusiasts, Hebron offers a unique opportunity to explore the intersection of human-made structures and natural ecosystems. Its historical significance, ongoing regulatory oversight, and high hazard potential make it a focal point for understanding the challenges and importance of managing water resources in a changing climate. As efforts to address aging infrastructure and enhance resilience continue, Hebron remains a valuable case study for studying the complex relationship between dams, rivers, and environmental stewardship.

Year Completed

1933

Dam Length

170

Dam Height

17

River Or Stream

BARK

Primary Dam Type

Gravity

Surface Area

28

Hydraulic Height

11

Drainage Area

163.5

Nid Storage

160

Structural Height

17

Hazard Potential

High

Nid Height

17
       
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.