Threlkeld Dam Reservoir Report

Last Updated: December 6, 2025

Threlkeld Dam, located in the Skunk River floodplain in Washington, Iowa, is a private-owned structure designed by USDA NRCS.


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Summary

Completed in 2010, this earth-type dam stands at a height of 32 feet and spans 200 feet in length. With a storage capacity of 44 acre-feet and a surface area of 3.1 acres, the primary purpose of Threlkeld Dam is for fire protection, stock, or small fish pond use.

Managed by the Iowa Department of Natural Resources, Threlkeld Dam is regulated, permitted, inspected, and enforced by state agencies. Despite its low hazard potential and current "Not Rated" condition assessment, no emergency action plan (EAP) or risk assessment has been prepared for the dam. The structure boasts a spillway width of 10 feet and a maximum discharge capacity of 25 cubic feet per second, serving as a crucial water resource for the area.

While Threlkeld Dam serves its primary purposes effectively, there is a need for further evaluation and preparation in terms of emergency response planning and risk assessment. As an integral component of the Skunk River watershed, this dam plays a vital role in water management and conservation efforts in the region. Climate and water resource enthusiasts are encouraged to monitor developments regarding Threlkeld Dam's safety and regulatory compliance to ensure its continued functionality and environmental impact.

Year Completed

2010

Dam Length

200

Dam Height

32

River Or Stream

TR-Skunk River

Primary Dam Type

Earth

Surface Area

3.1

Drainage Area

0.1

Nid Storage

44

Outlet Gates

None

Hazard Potential

Low

Foundations

Soil

Nid Height

32
       
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.