Dam Report

Overflow Weir Dam dam

New Jersey, USA Wanaque River Hazard High
Today high
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Tonight low
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Dam height
30ft
Hazard rating
High
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Overflow Weir Dam -- None dam
Overflow Weir Dam None · Wanaque River
About this dam

Overflow Weir Dam

Overflow Weir Dam, located in Passaic, New Jersey, is a state-owned structure built in 1928 with a primary purpose of water supply. The dam is situated on the Wanaque River and stands at a height of 30 feet, with a length of 552 feet. It has a storage capacity of 29,000 acre-feet and covers a surface area of 2,400 acres, serving the surrounding area with vital water resources.

As a regulated dam under the jurisdiction of the New Jersey Department of Environmental Protection (NJDEP), Overflow Weir Dam undergoes regular inspections to ensure its structural integrity and safety. With a high hazard potential but satisfactory condition assessment, the dam plays a crucial role in managing water resources and mitigating flood risks in the region. The dam is equipped with outlet gates and an emergency action plan, highlighting its importance in safeguarding the community in case of emergencies.

Overflow Weir Dam stands as a vital infrastructure in water resource management, providing essential water supply to the area while ensuring safety and regulatory compliance. With its strategic location and significant storage capacity, the dam serves as a key asset in maintaining water security and protecting the surrounding environment from potential hazards. Its history, design, and operational protocols make it a fascinating subject for enthusiasts interested in water resources and climate resilience.

StateNone
River / streamWanaque River
NID IDNJ00214
Owner typeState
Primary purposeWater Supply
Dam typeConcrete
Year built1928
Dam height30 ft
Dam length552 ft
Normal storage29,000 AF
Surface area2,400.0 ac
Drainage area90.4 sq mi
Hazard potentialHigh
ConditionSatisfactory
Last inspectionWed, 06 Oct 2021 12:00:00 GMT

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.
Detailed forecast

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.

Hourly detail

Next 5 days, hour by hour

Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.

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Deep dive

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.

TimeConditionTemp (°F)Snow (in)Rain (in)Humidity (%)Wind (mps)Wind dir
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Long-term outlook

15-day temperature & precipitation

Daily temperatures, snow, and rain projected over the next two weeks.

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Regional inflow

Nearby streamflow gauges

USGS streamgauges around Overflow Weir Dam -- inflows here typically show up in storage 24-72 hours later.

Track Overflow Weir 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.

FAQ

About Overflow Weir Dam

Where does the data for Overflow Weir 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 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.