Forty Acre Pond Dam Reservoir Report
Last Updated: December 20, 2025
Located in St.
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Summary
Marys, Ohio, the Forty Acre Pond Dam stands as a historic structure completed in 1840 along the Miami & Erie Canal. With a primary purpose of recreation, this earth dam spans 11,100 feet in length and reaches a height of 15 feet, providing a storage capacity of 492.1 acre-feet. Despite its age, the dam remains state-regulated and undergoes regular inspections by the Department of Natural Resources to ensure its safety and compliance with regulations.
The dam's condition is reported as poor, with a low hazard potential, signaling a need for maintenance and potential upgrades to enhance its resilience. The last inspection in October 2019 highlighted the dam's deteriorating condition, prompting concerns about its long-term stability. As a popular recreational site, preserving the Forty Acre Pond Dam is crucial not only for water resource management but also for the safety and enjoyment of visitors who frequent the area for various outdoor activities.
As climate change continues to impact water resources and infrastructure, the Forty Acre Pond Dam serves as a reminder of the importance of proactive maintenance and monitoring in ensuring the resilience of our dams and reservoirs. With its rich history and significant recreational value, efforts to improve the dam's condition and enhance its safety measures are essential to safeguarding both the environment and the community's well-being.
Year Completed |
1840 |
Dam Length |
11100 |
Dam Height |
15 |
River Or Stream |
MIAMI & ERIE CANAL |
Primary Dam Type |
Earth |
Surface Area |
68 |
Drainage Area |
1.8 |
Nid Storage |
492.1 |
Hazard Potential |
Low |
Nid Height |
15 |
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.
Forty Acre Pond Dam