J. Seward Johnson Dam

J. Seward Johnson Dam is an earth dam located in Hunterdon County, New Jersey, built in 1967. It carries a Low hazard potential classification and has a poor condition assessment.

About J. Seward Johnson Dam

The primary purpose of J. Seward Johnson Dam is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by James Loring Johnson (private). It impounds the Cold Brook near Oldwick.

The dam stands 24 feet tall and stretches 1,150 feet across, creates a reservoir covering 6 acres, has a storage capacity of 50 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1967, the structure is well into its service life at over 50 years old.

This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life. Its condition is rated poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. An emergency action plan is in place for this dam. The most recent inspection on record was 03/11/2021.

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Low HazardPoor ConditionEmergency Action Plan: Yes

Location

StateNew Jersey
CountyHunterdon
Nearest CityOldwick
River/StreamCold Brook
Coordinates40.68798, -74.75342

Physical Characteristics

Dam TypeEarth
NID Height24 ft
Dam Height24 ft
Dam Length1,150 ft
Year Completed1967 (59 years old)

Storage & Hydraulics

NID Storage50 acre-ft
Normal Storage50 acre-ft
Surface Area6 acres
Drainage Area0 sq mi
Max Discharge450 cfs

Ownership & Safety

PurposeIrrigation
OwnerJames Loring Johnson
Owner TypePrivate
Hazard ClassificationLow
Condition AssessmentPoor
Last Inspection03/11/2021
Emergency Action PlanYes

Identifiers

NID IDNJ00770
Federal IDNJ00770
More InfoState Dam Safety Program

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