Second Reservoir Dam dam
Second Reservoir Dam
Located in Thiells, New York, the Second Reservoir Dam is a significant earth dam completed in 1928 primarily for water supply purposes. With a height of 32 feet and a length of 440 feet, this dam holds a storage capacity of 272 acre-feet, serving as a crucial water resource for the region. The dam is regulated and inspected by the NYS DEC, ensuring its operational integrity and safety.
Despite its historical significance, the Second Reservoir Dam is currently rated as having a poor condition assessment, with a significant hazard potential. The last inspection in June 2019 revealed the need for improvements to meet safety standards. The dam's risk assessment is moderate, indicating the importance of implementing risk management measures to mitigate potential hazards and ensure the safety of the surrounding community and water resources. Climate and water resource enthusiasts will find the Second Reservoir Dam an intriguing subject for further study and monitoring to address its current condition and ensure its long-term sustainability.
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 Second Reservoir Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Mahwah River Near Suffern Ny | 18 cfs | → |
| Ramapo River At Ramapo Ny | 88 cfs | → |
| Ramapo River At Suffern Ny | 67 cfs | → |
| Ramapo River Near Mahwah Nj | 136 cfs | → |
| Hackensack River At West Nyack Ny | 18 cfs | → |
| Saddle River At Upper Saddle River Nj | 25 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Second Reservoir Dam.
Boat launches
- Battlefield Road Town Of Stony Point
- Cortlandt Street Cortlandt
- Broadway Buchanan
- Hudson Avenue Peekskill
- Bear Mountain Bridge Road Cortlandt
- Laurel Meadow Drive Town Of Warwick
Campgrounds
- Beaver Pond - Harriman State Park
- Beaver Pond Campsite
- Blue Mountain Reservation
- Croton Point Park
- Round Pond Military
- Camping For Hikers On Ballfield Graymoor Center
Fishing spots
Paddle runs
- Kent Bridge To Boardman Bridge
- Pond Downstream Of Shepaug Reservoir Dam, Marked By Service Road Bridge To Ends In Backwaters Of Lake Lillinonah, Near Roxbury Falls
- Begins Downstream Of The Borough Of Bantam, At Stoddard Road Bridge To The Confluence With The Shepaug River
Track Second Reservoir 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 Second Reservoir Dam
Where does the data for Second Reservoir 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 Second Reservoir Dam.