Duncan Dam Reservoir Report
Nearby: Falconer Dam Hale Lake Dam
Last Updated: December 24, 2025
Duncan Dam, located in Sumner, Missouri, is a privately owned earth dam designed by the USDA NRCS and completed in 2005 for grade stabilization along the TR-Locust Creek.
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Summary
The dam stands at a height of 27 feet with a hydraulic height of 25 feet and a structural height of 32 feet, providing essential flood control and water resource management for the area. With a storage capacity of 22.8 acre-feet and a surface area of 3 acres, Duncan Dam plays a crucial role in regulating the flow of water and protecting the surrounding environment.
Although categorized as having a low hazard potential, Duncan Dam is subject to moderate risk (3) due to its location and potential impact on the community in the event of a failure. Despite not being regularly inspected or assessed for condition, the dam's purpose of grade stabilization and its uncontrolled spillway and outlet gates highlight the importance of ongoing monitoring and maintenance to ensure its long-term safety and effectiveness. With a drainage area of 256 square miles and a maximum discharge of 11 cubic feet per second, Duncan Dam serves as a vital infrastructure for water resource management in Linn County, Missouri.
In the absence of state regulation or permitting for Duncan Dam, its design and construction by the Natural Resources Conservation Service underscore the collaborative efforts between private owners and federal agencies to enhance water resource infrastructure. As a key component of the Rock Island District's flood control system, Duncan Dam contributes to the overall resilience of the region against potential water-related hazards. With its strategic location and operational capacity, Duncan Dam stands as a testament to the importance of sustainable water resource management in the face of changing climate conditions and increasing water demands.
Year Completed |
2005 |
Dam Length |
270 |
Dam Height |
27 |
River Or Stream |
TR-LOCUST CREEK |
Primary Dam Type |
Earth |
Surface Area |
3 |
Hydraulic Height |
25 |
Drainage Area |
256 |
Nid Storage |
22.8 |
Structural Height |
32 |
Outlet Gates |
Uncontrolled |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
32 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Locust Creek Near Linneus
|
34cfs |
Medicine Creek Near Laredo
|
21cfs |
Grand River Near Sumner
|
240cfs |
Grand River At Chillicothe
|
361cfs |
Thompson River At Trenton
|
95cfs |
Mussel Fork Near Musselfork
|
16cfs |
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.
Duncan Dam