Hendrickson Marsh Dam Reservoir Report

Last Updated: December 13, 2025

Hendrickson Marsh Dam, located in Marshall County, Iowa, serves as a vital recreational resource for the local community.


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Summary

Completed in 1967, this earth dam stands at 18 feet high and stretches 321 feet in length, holding a storage capacity of 2,800 acre-feet. With a surface area of 264 acres and a drainage area of 13.19 square miles, the dam's primary purpose is to provide recreational opportunities for visitors in the area.

Managed by the Iowa Department of Natural Resources, the dam has a low hazard potential and is in satisfactory condition as of the last assessment in June 2020. The dam features an uncontrolled spillway with a width of 35 feet, ensuring the safe release of excess water during periods of high flow. Despite its moderate risk rating, the dam is regularly inspected and maintained to uphold safety standards and mitigate any potential risks to surrounding communities.

As a significant feature along the Marshall-Story D.D. #2 river system, Hendrickson Marsh Dam plays a crucial role in water resource management and climate resilience efforts in the region. Its presence not only enhances recreational opportunities but also serves as a reminder of the importance of sustainable infrastructure development in safeguarding our natural environment for future generations.

Year Completed

1967

Dam Length

321

Dam Height

18

River Or Stream

MARSHALL-STORY D.D. #2

Primary Dam Type

Earth

Surface Area

264

Drainage Area

13.19

Nid Storage

2800

Hazard Potential

Low

Foundations

Soil

Nid Height

18
       
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.