South Forebay Dike dam
South Forebay Dike
South Forebay Dike, located in Cornwall, New York, is a state-owned earth dam built in 1958 by Chas. T. Main for hydroelectric and navigation purposes along the St. Lawrence River. The dam stands at a height of 136 feet and spans a length of 8400 feet, with a storage capacity of 803,000 acre-feet and a surface area of 37,500 acres. Despite being state-regulated, the dam has a high hazard potential and is under the jurisdiction of the Federal Energy Regulatory Commission for inspections and regulatory oversight.
The South Forebay Dike is part of a network of six associated structures, contributing to the overall water management and power generation in the region. With a drainage area of 300,000 square miles, the dam plays a crucial role in controlling water flow and ensuring the safety of downstream communities. Although the condition assessment is not available, the dam has a risk assessment rating of high (2), emphasizing the importance of regular inspections and maintenance to prevent potential hazards and ensure structural integrity.
Given its significance for hydroelectric power generation and water resource management, South Forebay Dike serves as a vital infrastructure in the region. With Elise M. Stefanik (R) representing the area in Congress, ongoing efforts are needed to address any potential risks and ensure the continued safety and efficiency of the dam for both environmental and economic sustainability in the face of changing climate conditions.
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 South Forebay Dike -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| St. Regis River At Brasher Center Ny | 1,150 cfs | → |
| Little Salmon River At Bombay Ny | 114 cfs | → |
| Raquette River At Raymondville Ny | 2,050 cfs | → |
| Grass River At Chase Mills Ny | 992 cfs | → |
| W Br St. Regis R Nr Parishville Ny | 362 cfs | → |
| Raquette River At South Colton Ny | 1,050 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near South Forebay Dike .
Boat launches
- Long Sault Parkway 15702, Long Sault
- Water Street West Cornwall
- Long Sault Parkway 15417, Ingleside
- Ny 131 Saint Lawrence County
- Wilson Hill Causeway Saint Lawrence County
- St Regis River
Track South Forebay Dike 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 South Forebay Dike
Where does the data for South Forebay Dike 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 South Forebay Dike .