Twelve Mile Creek Watershed Site 77 Reservoir Report
Nearby: Claiser Dam Hawk Lake Dam
Last Updated: December 12, 2025
Twelve Mile Creek Watershed Site 77, located in Afton, Iowa, is a dam with a primary purpose of fire protection, stock, or small fish pond, as well as flood risk reduction.
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Summary
Built in 1979 by the USDA NRCS, this earth dam stands at a height of 22 feet and has a length of 650 feet, with a storage capacity of 65 acre-feet. The dam serves as a crucial component in managing water resources in the area.
Managed by the Iowa DNR, this dam is state regulated, permitted, inspected, and enforced to ensure its safety and functionality. With a low hazard potential and a moderate risk assessment rating, the dam plays a vital role in mitigating flood risks and protecting the surrounding environment. The site covers a drainage area of 0.3 square miles and has a surface area of 5.7 acres, making it an essential structure in the Twelve Mile Creek watershed.
As an integral part of the water management system in Union County, Iowa, Twelve Mile Creek Watershed Site 77 serves multiple purposes while upholding safety and regulatory standards. With its strategic location and design, this dam contributes to the overall resilience of the watershed and helps protect the community from potential water-related hazards. For water resource and climate enthusiasts, this site offers valuable insights into the intersection of infrastructure, regulation, and environmental stewardship in managing water resources.
Year Completed |
1979 |
Dam Length |
650 |
Dam Height |
22 |
River Or Stream |
TR-TWELVE MILE CREEK |
Primary Dam Type |
Earth |
Surface Area |
5.7 |
Drainage Area |
0.3 |
Nid Storage |
65 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
22 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
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 77