Twelve Mile Creek Watershed Site 40-1 Reservoir Report
Last Updated: December 14, 2025
Twelve Mile Creek Watershed Site 40-1, located in Union County, Iowa, is a small earth dam completed in 1993 with a primary purpose of fire protection, stock, or small fish pond.
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Summary
The dam stands at a height of 33 feet, with a length of 536 feet, and a storage capacity of 279 acre-feet. With a drainage area of 0.85 square miles, the dam serves multiple purposes including flood risk reduction.
Managed by the Natural Resources Conservation Service, this dam is regulated by the Iowa Department of Natural Resources and has a low hazard potential. The risk assessment for the site is moderate, indicating a potential for some risk but manageable with appropriate measures in place. While the condition assessment is not rated, the dam is inspected, permitted, and enforced by state authorities, ensuring its safety and functionality for the community. As a part of the Twelve Mile Creek watershed, this site plays a crucial role in water resource management and climate resilience efforts in the region.
Year Completed |
1993 |
Dam Length |
536 |
Dam Height |
33 |
River Or Stream |
TR- TWELVE MILE CREEK |
Primary Dam Type |
Earth |
Surface Area |
11.8 |
Drainage Area |
0.85 |
Nid Storage |
279 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
33 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Thompson River At Davis City
|
22cfs |
East Fork 102 River At Bedford
|
1cfs |
Raccoon River At Van Meter
|
1640cfs |
South Raccoon River At Redfield
|
268cfs |
North River Near Norwalk
|
48cfs |
Raccoon River Near West Des Moines
|
1300cfs |
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.
Twelve Mile Creek Watershed Site 40-1