Lake Thunderhead Dam Reservoir Report
Nearby: Johnson-6 Dam Lake Mahoney Dam
Last Updated: December 12, 2025
Lake Thunderhead Dam, located in Putnam, Missouri, is a privately owned structure that serves primarily for recreation purposes.
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Summary
Completed in 1965, this earth dam stands at a height of 54 feet and stretches over a length of 1400 feet, impounding a maximum storage capacity of 28,690 acre-feet. With a surface area of 1015 acres and a drainage area of 16,515 acres, the dam controls the flow of the North Blackbird Creek and boasts a spillway width of 250 feet.
Despite its satisfactory condition assessment as of 2007, Lake Thunderhead Dam is classified with a high hazard potential, demanding frequent inspections every three years. The dam has a moderate risk assessment score of 3, indicating a need for continued monitoring and risk management measures. While the dam currently lacks an Emergency Action Plan (EAP) and inundation maps, its regulatory oversight by the Dam and Reservoir Safety Program of Missouri ensures that necessary enforcement and safety measures are in place. Lake Thunderhead Dam stands as a vital structure for both recreational enjoyment and water resource management in the region.
Year Completed |
1965 |
Dam Length |
1400 |
Dam Height |
54 |
River Or Stream |
NORTH BLACKBIRD CREEK |
Primary Dam Type |
Earth |
Surface Area |
1015 |
Drainage Area |
16515 |
Nid Storage |
28690 |
Structural Height |
54 |
Outlet Gates |
None |
Hazard Potential |
High |
Foundations |
Rock |
Nid Height |
54 |
Seasonal Comparison
Weather Forecast
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.
Lake Thunderhead Dam