Tappan Dam Reservoir Report
Last Updated: December 5, 2025
Tappan Dam, also known as Tappan Lake, is a federally owned structure located in Ohio's Harrison County.
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Summary
Completed in 1936 by the US Army Corps of Engineers, this earth-type dam serves primarily for flood risk reduction along Little Stillwater Creek. With a hydraulic height of 45 feet and a structural height of 52 feet, the dam spans 1550 feet and has a storage capacity of 61,600 acre-feet.
Despite its high hazard potential, Tappan Dam is equipped with an emergency action plan, updated regularly by the US Army Corps of Engineers, to manage flood risks effectively. The dam releases water to adjust levels upstream and downstream, safeguarding its structural integrity. The Corps actively collaborates with local emergency managers and the public to enhance dam awareness and preparedness for potential emergencies. Through constant monitoring and maintenance, the Corps ensures the dam's proper functioning and mitigates risks associated with severe weather events.
In conclusion, Tappan Dam stands as a crucial structure for flood control in Ohio, demonstrating the US Army Corps of Engineers' commitment to safeguarding water resources and enhancing community resilience against dam-related emergencies.
Year Completed |
1936 |
Dam Length |
1550 |
River Or Stream |
LITTLE STILLWATER CREEK |
Primary Dam Type |
Earth |
Surface Area |
2350 |
Hydraulic Height |
45 |
Drainage Area |
71 |
Nid Storage |
61600 |
Structural Height |
52 |
Hazard Potential |
High |
Foundations |
Soil |
Nid Height |
52 |
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.
Tappan Dam