Grossingers Lake Dam dam
Grossingers Lake Dam
Grossingers Lake Dam, located in Harris, Sullivan County, New York, is a privately owned earth dam built in 1950 for recreational purposes. With a height of 15 feet and a length of 200 feet, the dam holds a maximum storage capacity of 245 acre-feet of water in Grossingers Lake. The dam is situated on the TR-East Mongaup River and is regulated by the New York State Department of Environmental Conservation (NYS DEC).
The dam has a spillway type of "Uncontrolled" with a width of 20 feet, allowing for a maximum discharge of 515 cubic feet per second. The hazard potential of the dam is considered significant, with a moderate risk rating. Although the condition of the dam is currently not rated, it undergoes inspections every 4 years, with the last inspection conducted in June 2019. The dam does not have an Emergency Action Plan (EAP) in place, but the risk management measures for potential emergencies are not specified.
For water resource and climate enthusiasts, Grossingers Lake Dam presents an interesting case study of a privately owned recreational dam in New York. The dam's location on the TR-East Mongaup River and its significance in water storage and discharge highlight the importance of proper regulation and maintenance to ensure the safety of surrounding communities. Further research and monitoring of the dam's condition and risk assessment may provide valuable insights into sustainable water management practices in the region.
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 Grossingers Lake Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Neversink River At Neversink Ny | 108 cfs | → |
| Mongaup River At Mongaup Valley Ny | 65 cfs | → |
| Neversink River Near Claryville Ny | 106 cfs | → |
| Chestnut Creek At Grahamsville Ny | 26 cfs | → |
| West Branch Neversink R At Claryville | 47 cfs | → |
| Neversink River At Bridgeville Ny | 136 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Grossingers Lake Dam.
Boat launches
- Starlight Road 55, Monticello
- State Highway 55a Town Of Wawarsing
- Delaware River
- Callicoon
- Plank Road Town Of Forestburgh
- Damascus
Track Grossingers Lake 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 Grossingers Lake Dam
Where does the data for Grossingers Lake 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 Significant 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 Grossingers Lake Dam.