Hess Dam Reservoir Report

Last Updated: December 5, 2025

Hess Dam, located in Worthington, Iowa, was completed in 1970 and serves multiple purposes including fire protection and maintaining a small fish pond.


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Summary

Managed by a private owner, the dam stands at 26 feet tall and spans 500 feet in length, with a storage capacity of 72 acre-feet. It is regulated by the Iowa DNR and undergoes regular inspections, with a low hazard potential and a moderate risk assessment rating.

The dam, designed by USDA NRCS, is primarily made of earth and founded on soil. It is situated on the TR-Durion Branch river and is owned by a private entity. While it does not have a controlled spillway, the dam has a normal storage capacity of 33 acre-feet and covers a surface area of 5 acres. The risk assessment for the dam is considered moderate, with no official condition rating provided.

Overall, Hess Dam plays a crucial role in water resource management and contributes to the local ecosystem in Worthington, Iowa. With its multifunctional purposes and regulated operations, the dam provides essential services while mitigating potential risks associated with its structure. For water resource and climate enthusiasts, this dam serves as a focal point for understanding the intersection of human infrastructure with natural environments.

Year Completed

1970

Dam Length

500

Dam Height

26

River Or Stream

TR-DURION BRANCH

Primary Dam Type

Earth

Surface Area

5

Drainage Area

0.5

Nid Storage

72

Hazard Potential

Low

Foundations

Soil

Nid Height

26
       
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.