West Sunnyside Watershed Site C-3 Reservoir Report

Last Updated: December 15, 2025

Located in Plymouth, Iowa, the West Sunnyside Watershed Site C-3 is a local government-owned dam constructed in 1973 by the USDA NRCS.


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Summary

This earth dam, standing at a height of 54 feet and spanning a length of 720 feet, serves multiple purposes including fire protection, stock, small fish pond, and flood risk reduction. With a storage capacity of 114 acre-feet and a drainage area of 0.35 square miles, this dam plays a crucial role in managing water resources in the area.

Situated on TR-Broken Kettle Creek, this dam is regulated by the Iowa DNR and has a low hazard potential with a moderate risk assessment rating. While the condition assessment is currently marked as "Not Rated," the dam is subject to state inspection, permitting, and enforcement. Despite its uncontrolled spillway type, the West Sunnyside Watershed Site C-3 remains an essential structure for water resource management in the region, ensuring the safety and protection of surrounding communities.

With its strategic location in Sioux City and its operational history dating back to almost five decades, the West Sunnyside Watershed Site C-3 stands as a testament to effective water resource management in Iowa. As climate change continues to pose challenges to water availability and quality, this dam serves as a critical infrastructure for mitigating flood risks, providing fire protection, and supporting local ecosystems. Its significance in the region underscores the importance of sustainable water resource practices and the need for ongoing monitoring and maintenance to ensure its continued functionality.

Year Completed

1973

Dam Length

720

Dam Height

54

River Or Stream

TR-BROKEN KETTLE CREEK

Primary Dam Type

Earth

Surface Area

6.4

Drainage Area

0.35

Nid Storage

114

Hazard Potential

Low

Foundations

Soil

Nid Height

54
       
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.