Croghan Island Dam dam
Croghan Island Dam
Croghan Island Dam, located in Croghan, Lewis County, New York, is a privately owned concrete dam on the Beaver River that was completed in 1919. With a height of 12 feet and a length of 260 feet, this dam provides a normal storage capacity of 482 acre-feet and a maximum storage capacity of 797 acre-feet. The dam's surface area covers 121 acres, serving a drainage area of 293 square miles.
Despite being classified as having a low hazard potential and a moderate risk assessment, Croghan Island Dam is regulated, permitted, inspected, and enforced by the New York State Department of Environmental Conservation (NYS DEC). The dam's spillway, with a width of 180 feet, is uncontrolled. Although the dam's condition assessment is not rated, an Emergency Action Plan (EAP) was last revised in 2010. The dam is not owned or funded by any federal agency, making it a noteworthy example of a privately managed structure contributing to water resource management in the region.
For water resource and climate enthusiasts, Croghan Island Dam represents a historical and functional component of the Beaver River watershed. Its presence ensures water storage and management for the surrounding area, showcasing the importance of private ownership in maintaining essential infrastructure. With its long-standing history and ongoing regulatory oversight, this dam serves as a reminder of the critical role of dams in balancing water supply, flood control, and environmental protection in New York State.
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 Croghan Island Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Beaver River At Croghan Ny | 893 cfs | → |
| Independence River At Donnattsburg Ny | 219 cfs | → |
| West Branch Oswegatchie R Nr Harrisville Ny | 633 cfs | → |
| Black River Near Boonville Ny | 964 cfs | → |
| Black River At Watertown Ny | 4,300 cfs | → |
| Oswegatchie River Near Oswegatchie Ny | 832 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Croghan Island Dam.
Boat launches
Campgrounds
- Whetstone Gulf State Park
- Remington Park Rv Military - Fort Drum
- Nicks Lake - Dec
- Oswegatchie 41/High Rock
- Oswegatchie 42
- Oswegatchie 43
Track Croghan Island Dam 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 Croghan Island Dam
Where does the data for Croghan Island Dam 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 Low 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 Croghan Island Dam.