Grand Lake St. Marys - West Embankment Reservoir Report
Last Updated: December 19, 2025
Grand Lake St.
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Summary
Marys - West Embankment is a state-managed dam located in Celina, Ohio, along the Beaver Creek. Built in 1841 by Walter H. Weyrich, this earth dam stands at a height of 19.5 feet and stretches over 4800 feet, providing essential recreation opportunities for the community. The dam has a storage capacity of 156,383 acre-feet and covers a surface area of 13,981 acres, making it a popular destination for water resource and climate enthusiasts in Mercer County.
Despite its historical significance, the dam at Grand Lake St. Marys - West Embankment is currently rated as having a high hazard potential and a poor condition assessment as of the last inspection in November 2019. This raises concerns about its structural integrity and the potential risks it poses to the surrounding area. With the Department of Natural Resources overseeing state regulation, inspection, and enforcement, efforts to address these issues and ensure the safety of the dam are crucial for the preservation of this iconic water resource.
As climate change continues to impact water resources, the maintenance and upkeep of structures like the Grand Lake St. Marys - West Embankment dam become increasingly important. With a focus on recreation, it serves as a reminder of the delicate balance between human enjoyment and ecological sustainability. By implementing necessary risk management measures and staying vigilant in monitoring its condition, this dam can continue to be a valuable asset for the community while protecting the natural environment for generations to come.
Year Completed |
1841 |
Dam Length |
4800 |
Dam Height |
19.5 |
River Or Stream |
BEAVER CREEK |
Primary Dam Type |
Earth |
Surface Area |
13981 |
Drainage Area |
110.3 |
Nid Storage |
156383 |
Hazard Potential |
High |
Nid Height |
20 |
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.
Grand Lake St. Marys - West Embankment