Dam Report

Pocahontas Dam dam

New Jersey, USA Whippany River Hazard High
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Tonight low
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Dam height
11ft
Hazard rating
High
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Pocahontas Dam -- None dam
Pocahontas Dam None · Whippany River
About this dam

Pocahontas Dam

Pocahontas Dam, located in Morris County, New Jersey, is a concrete dam completed in 1920 on the Whippany River. With a height of 11.3 feet and a length of 168 feet, the dam serves primarily for recreational purposes, offering opportunities for boating, fishing, and other water-based activities. The reservoir created by Pocahontas Dam has a normal storage capacity of 39 acre-feet, providing a serene escape for locals and visitors alike.

Despite its age, Pocahontas Dam is regularly inspected and maintained to ensure its safety and structural integrity. The dam has a high hazard potential, but its condition assessment as of October 2021 was rated as fair. Emergency action plans are in place, with inspections conducted every two years to address any potential risks or issues that may arise. The dam's location in Morristown, with easy access to surrounding areas, makes it a valuable water resource for the community and an important site for climate enthusiasts interested in the intersection of water management and recreation.

In addition to its recreational benefits, Pocahontas Dam plays a crucial role in managing water flow and providing flood protection for the region. With a drainage area of 25.3 square miles and a maximum discharge capacity of 1565 cubic feet per second, the dam helps mitigate the risk of flooding during periods of heavy rainfall. The reservoir created by the dam covers a surface area of 15 acres and has a total storage capacity of 74 acre-feet, making it an essential component of the local water infrastructure. As climate change impacts become more pronounced, the importance of sustainable water resource management, exemplified by Pocahontas Dam, only continues to grow.

StateNone
River / streamWhippany River
NID IDNJ00360
Owner typeLocal Government
Primary purposeRecreation
Dam typeConcrete
Year built1920
Dam height11 ft
Dam length168 ft
Max storage74 AF
Normal storage39 AF
Surface area15.0 ac
Drainage area25.3 sq mi
Hazard potentialHigh
ConditionFair
Last inspectionFri, 15 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 Pocahontas Dam -- inflows here typically show up in storage 24-72 hours later.

Track Pocahontas 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 Pocahontas Dam

Where does the data for Pocahontas 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.