Grand Lake St. Marys - East Embankment dam
Grand Lake St. Marys - East Embankment
Grand Lake St. Marys - East Embankment, located in St. Marys, Ohio, is a state-regulated dam built in 1841 with a primary purpose of recreation. The dam is an earth type structure standing at a height of 17.9 feet and spanning 7980 feet in length. It boasts a storage capacity of 62,194 acre-feet, supporting a surface area of 13,981 acres and draining a 110.3 square mile watershed.
Managed by the Department of Natural Resources, the dam has a high hazard potential but is currently rated in fair condition as of the last assessment in November 2019. While the dam has not undergone recent modifications, it is subject to regular state inspections and enforcement measures to ensure public safety. With its outlet leading to the Miami and Erie Canal Feeder, the dam serves as a vital component of the local water resource infrastructure, offering both recreational opportunities and flood control benefits to the surrounding community.
Grand Lake St. Marys - East Embankment stands as a historic landmark in Auglaize County, Ohio, designed by John H. Irwin. With its scenic surroundings and important role in water management, the dam continues to be a focal point for water resource and climate enthusiasts interested in the intersection of human infrastructure and natural ecosystems.
Dam data reference
Condition Assessment
- Satisfactory
- No 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.
- 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.
- 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.
Hazard Potential Classification
- High
- Dams 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, environmental 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.
Plan around the weather
Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind. Each cell is colour-coded relative to the column min/max.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around Grand Lake St. Marys - East Embankment -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Beaver Creek Near Celina Oh | 67 cfs | → |
| Loramie Creek Near Fort Loramie Oh | 47 cfs | → |
| Auglaize River Near Kossuth Oh | 16 cfs | → |
| Loramie Creek Near Newport Oh | 835 cfs | → |
| St. Marys River At Rockford Oh | 269 cfs | → |
| Ottawa River At Lima Oh | 580 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Grand Lake St. Marys - East Embankment.
Boat launches
- Lutman Road Launch Ramp
- Lakeview Harbor Boat Ramp
- Indian Lake State Park - Campground Ramp
- Chippewa Marina
- Moundwood Boat Ramp
- Long Island Point
Track Grand Lake St. Marys - East Embankment in the Snoflo app
Save this dam as a favorite and get the local NOAA / yr.no forecast plus regional flow context wherever you are.
About Grand Lake St. Marys - East Embankment
Where does the data for Grand Lake St. Marys - East Embankment come from?
Structural and regulatory data come from the U.S. Army Corps of Engineers' National Inventory of Dams (NID). Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.
How often is the report updated?
NID structural data refreshes annually as the Corps publishes updated assessments. The weather forecast refreshes throughout the day.
What does the High hazard rating mean?
The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card above for the full definitions.
What's "% of normal"?
The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).
Can I get alerts when storage crosses a threshold?
Yes -- alerts are managed in the Snoflo iOS app. Favorite this dam, set a threshold, and you'll get a push the moment conditions cross.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Grand Lake St. Marys - East Embankment.