West Sunnyside Watershed Site C-4 Reservoir Report
Last Updated: December 14, 2025
West Sunnyside Watershed Site C-4 is a crucial water resource located in Plymouth County, Iowa, specifically in the city of Sioux City.
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Summary
This site, managed by the local government, serves multiple purposes including fire protection, stock, and small fish pond management, as well as flood risk reduction. Constructed in 1973 by the USDA NRCS, this Earth-type dam stands at 52 feet tall and spans 456 feet in length, with a storage capacity of 115 acre-feet and a drainage area of 0.52 square miles.
Despite being classified as having a low hazard potential, West Sunnyside Watershed Site C-4 is subject to state regulation, inspection, and enforcement by the Iowa Department of Natural Resources. The dam has not been rated for its condition assessment, but its risk assessment is moderate. With a surface area of 6.1 acres and a normal storage capacity of 79 acre-feet, this site plays a critical role in water management and safety in the region. Its location near TR-Broken Kettle Creek highlights its importance in flood risk reduction efforts.
Overall, West Sunnyside Watershed Site C-4 is a significant water resource infrastructure that contributes to the overall water management and safety in the Plymouth County area. With its multiple purposes and regulatory oversight, this site showcases the importance of sustainable and effective water resource management practices in mitigating flood risks and ensuring community safety.
Year Completed |
1973 |
Dam Length |
456 |
Dam Height |
52 |
River Or Stream |
TR-BROKEN KETTLE CREEK |
Primary Dam Type |
Earth |
Surface Area |
6.1 |
Drainage Area |
0.52 |
Nid Storage |
115 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
52 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Perry Creek Near Milnerville
|
25cfs |
Big Sioux River At Akron
|
816cfs |
Floyd River At James
|
187cfs |
Missouri River At Sioux City
|
13700cfs |
Vermillion River Nr Vermillion Sd
|
33cfs |
Omaha Cr At Homer
|
45cfs |
Dam Data Reference
Condition Assessment
SatisfactoryNo 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
HighDams 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.
West Sunnyside Watershed Site C-4