Dam Report

Cedar Grove South Res Dam dam

New Jersey, USA Offstream Hazard High
Today high
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Tonight low
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Dam height
51ft
Hazard rating
High
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Cedar Grove South Res Dam -- None dam
Cedar Grove South Res Dam None · Offstream
About this dam

Cedar Grove South Res Dam

Cedar Grove South Reservoir Dam, located in Little Falls, Essex County, New Jersey, is a vital water supply structure owned by the local government. Built in 1903, this Earth-type dam stands at a height of 51 feet and spans 587 feet in length. It provides a maximum storage capacity of 2584 acre-feet, with a normal storage capacity of 2080 acre-feet, serving the surrounding area with essential water resources.

Managed by the New Jersey Department of Environmental Protection (NJDEP), Cedar Grove South Reservoir Dam is regulated, inspected, and enforced to ensure its safety and functionality. Despite being classified as a high hazard potential structure, the dam is in satisfactory condition as of the last assessment in April 2021. With a hazard potential rating of 'High', the dam is regularly inspected every two years to maintain its integrity and ensure public safety.

Congressional District 11, represented by Mikie Sherrill, oversees this crucial water supply infrastructure, emphasizing the importance of its maintenance and emergency preparedness. The dam's strategic location in Cedar Grove Township contributes significantly to the water resources management of the region, making it a key asset for water resource and climate enthusiasts interested in sustainable infrastructure development and management.

StateNone
River / streamOffstream
NID IDNJ00549
Owner typeLocal Government
Primary purposeWater Supply
Dam typeEarth
Year built1903
Dam height51 ft
Dam length587 ft
Max storage2,584 AF
Normal storage2,080 AF
Surface area98.0 ac
Drainage area0.4 sq mi
Hazard potentialHigh
ConditionSatisfactory
Last inspectionTue, 13 Apr 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 Cedar Grove South Res Dam -- inflows here typically show up in storage 24-72 hours later.

Track Cedar Grove South Res 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 Cedar Grove South Res Dam

Where does the data for Cedar Grove South Res 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.