Ashokan Dam

Ashokan Dam is an earth dam located in Ulster County, New York, built in 1916. It carries a High hazard potential classification and has a satisfactory condition assessment.

About Ashokan Dam

The primary purpose of Ashokan Dam is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by Nycdep Dams West Of The Hudson River (local government). It impounds the Esopus Creek near Olive Bridge.

The dam stands 213 feet tall and stretches 4,650 feet across, creates a reservoir covering 7,923 acres, has a maximum storage capacity of 512,500 acre-feet, and collects water from a drainage area of 256 square miles. Completed in 1916, the structure is over a century old.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 10/21/2022.

At 213 feet, this dam is taller than 99% of all dams in the United States.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The New York dam safety program can provide more specific information about emergency planning for this structure.

Search for dams near your address to see all dams in your area with hazard classifications and safety data.

High HazardSatisfactory ConditionEmergency Action Plan: Yes

Location

StateNew York
CountyUlster
Nearest CityOlive Bridge
River/StreamEsopus Creek
Coordinates41.93806, -74.21917

Physical Characteristics

Dam TypeEarth
NID Height213 ft
Dam Height213 ft
Dam Length4,650 ft
Year Completed1916 (110 years old)

Storage & Hydraulics

NID Storage512,500 acre-ft
Max Storage512,500 acre-ft
Normal Storage392,498 acre-ft
Surface Area7,923 acres
Drainage Area256 sq mi
Max Discharge209,700 cfs
Spillway TypeUncontrolled

Ownership & Safety

PurposeWater Supply
OwnerNYCDEP DAMS WEST OF THE HUDSON RIVER
Owner TypeLocal Government
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection10/21/2022
Emergency Action PlanYes

Identifiers

NID IDNY00041
Federal IDNY00041
More InfoState Dam Safety Program

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