Upper Twin Lakes Dam dam
Upper Twin Lakes Dam
The Upper Twin Lakes Dam in Pompton Lakes, New Jersey, is a private dam that serves primarily for recreation purposes. Situated on Irish Brook, this earth and gravity dam stands at a height of 7 feet and stretches 270 feet in length. With a storage capacity of 61 acre-feet and a surface area of 20 acres, it provides a picturesque setting for outdoor activities in the Wanaque Borough.
Despite its low hazard potential, the dam's condition assessment is rated as poor, with the last inspection conducted in August 2018. It is regulated by the New Jersey Department of Environmental Protection and undergoes regular inspections, permitting, and enforcement to ensure public safety. The dam's emergency action plan was last revised in October 2010, and risk management measures are in place to mitigate any potential threats.
Water resource and climate enthusiasts will appreciate the vital role that the Upper Twin Lakes Dam plays in providing recreational opportunities while also highlighting the importance of proper maintenance and monitoring to ensure its structural integrity and safety for the surrounding community. As part of the Philadelphia District, this dam represents a balance between human enjoyment of natural resources and the need for responsible infrastructure management in the face of changing environmental 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 Upper Twin Lakes Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Pequannock River At Riverdale Nj | 29 cfs | → |
| Wanaque R At Wanaque Nj | 14 cfs | → |
| Ramapo River At Pompton Lakes Nj | 122 cfs | → |
| Pompton River At Pompton Plains Nj | 145 cfs | → |
| West Brook Near Wanaque Nj | 7 cfs | → |
| Pequannock R At Macopin Intake Dam Nj | 14 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Upper Twin Lakes Dam.
Boat launches
- Lakeside Avenue Pompton Lakes
- North Corporate Drive 2, Riverdale
- Greenwood Lake Turnpike Ringwood
- Ringwood-Ramapo Trail Ringwood
- Island Avenue Little Falls
- Blue Lake Road Town Of Warwick
Track Upper Twin Lakes 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 Upper Twin Lakes Dam
Where does the data for Upper Twin Lakes 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 Upper Twin Lakes Dam.