Three Mile Creek Watershed Site 66 Reservoir Report
Last Updated: December 12, 2025
Three Mile Creek Watershed Site 66, located in Adair, Iowa, is a vital earth dam constructed in 1969 for multiple purposes including fire protection, stock, small fish pond, and flood risk reduction.
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Summary
Managed by the USDA NRCS, this dam stands at a height of 23 feet, with a length of 630 feet, and a storage capacity of 63 acre-feet. With a low hazard potential and moderate risk assessment, this dam plays a crucial role in water resource management in the area.
The dam, situated on TR-Three Mile Cr, is regulated by the Iowa DNR and is subject to state jurisdiction, permitting, inspection, and enforcement. It serves as a key component in the watershed's infrastructure, providing essential services while also minimizing flood risks. With a surface area of 5.1 acres and a drainage area of 0.19 square miles, this dam helps to control water flow and protect the surrounding environment from potential hazards.
As a part of the larger Three Mile Creek watershed, Site 66 is a critical asset that contributes to the overall water resource management efforts in the region. With its strategic location and structural design, this dam exemplifies the importance of sustainable infrastructure for climate resilience and water security.
Year Completed |
1969 |
Dam Length |
630 |
Dam Height |
23 |
River Or Stream |
TR-THREE MILE CR |
Primary Dam Type |
Earth |
Surface Area |
5.1 |
Drainage Area |
0.19 |
Nid Storage |
63 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
23 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
South Raccoon River At Redfield
|
268cfs |
Raccoon River At Van Meter
|
1640cfs |
Middle Raccoon River At Panora
|
92cfs |
Raccoon River Near West Des Moines
|
1300cfs |
East Nishnabotna River Near Atlantic
|
143cfs |
North River Near Norwalk
|
48cfs |
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.
Three Mile Creek Watershed Site 66