Three Mile Creek Watershed Site 3 Reservoir Report

Last Updated: December 11, 2025

Three Mile Creek Watershed Site 3, located in Union County, Iowa, is a significant earth dam structure built in 1970 by the USDA NRCS.


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Summary

The dam serves multiple purposes including fire protection, stock, small fish pond, and flood risk reduction. With a height of 33 feet and a length of 420 feet, the dam has a storage capacity of 51 acre-feet and covers a surface area of 3.8 acres. It is regulated, permitted, inspected, and enforced by the Iowa Department of Natural Resources, ensuring its safety and compliance with state regulations.

Despite being classified as low hazard potential, the site has a moderate risk assessment score of 3. The dam's condition is currently not rated, and there is no information available on emergency action plans or risk management measures. The structure is not owned or funded by federal agencies, but it is maintained and operated by local government authorities. With its crucial role in water resource management and flood control in the Three Mile Creek watershed, the dam at Site 3 plays a vital role in protecting the surrounding area from potential water-related disasters.

For water resource and climate enthusiasts, Three Mile Creek Watershed Site 3 offers a fascinating case study in dam infrastructure and management. The dam's design, construction, and regulatory oversight provide valuable insights into the complexities of water resource management and the importance of maintaining critical infrastructure for both practical and environmental purposes. As a key component of the watershed's ecosystem, understanding and monitoring the dam at Site 3 is essential for ensuring the sustainability and resilience of this vital water resource in Union County, Iowa.

Year Completed

1970

Dam Length

420

Dam Height

33

River Or Stream

TR-THREE MILE CREEK

Primary Dam Type

Earth

Surface Area

3.8

Drainage Area

0.15

Nid Storage

51

Hazard Potential

Low

Foundations

Soil

Nid Height

33
       
Seasonal Comparison

Weather Forecast

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Nearby Streamflow Levels

Three Mile Creek Watershed Site 3Thompson River at Davis City Preview Thompson River At Davis City
22.4cfs
22cfs
Three Mile Creek Watershed Site 3Raccoon River at Van Meter Preview Raccoon River At Van Meter
1640.0cfs
1640cfs
Three Mile Creek Watershed Site 3South Raccoon River at Redfield Preview South Raccoon River At Redfield
268.0cfs
268cfs
Three Mile Creek Watershed Site 3North River near Norwalk Preview North River Near Norwalk
48.0cfs
48cfs
Three Mile Creek Watershed Site 3Raccoon River near West Des Moines Preview Raccoon River Near West Des Moines
1300.0cfs
1300cfs
Three Mile Creek Watershed Site 3Middle River near Indianola Preview Middle River Near Indianola
47.5cfs
48cfs

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.
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Nearby Reservoirs

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