Onota Lake Dam

Onota Lake Dam is a concrete dam located in Berkshire County, Massachusetts, built in 1865. It carries a High hazard potential classification and has a satisfactory condition assessment.

About Onota Lake Dam

The primary purpose of Onota Lake Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by City Of Pittsfield (local government). It impounds the Pecks/onota Brook near Pittsfield.

The dam stands 18 feet tall and stretches 240 feet across, creates a reservoir covering 660 acres, has a maximum storage capacity of 6,800 acre-feet, and collects water from a drainage area of 10 square miles. Completed in 1865, the structure is one of the older dams in the region, with over a century and a half of service.

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 04/11/2023.

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 Massachusetts 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

StateMassachusetts
CountyBerkshire
Nearest CityPittsfield
River/StreamPecks/onota Brook
Coordinates42.47626, -73.26719

Physical Characteristics

Dam TypeConcrete
NID Height18 ft
Dam Length240 ft
Year Completed1865 (161 years old)

Storage & Hydraulics

NID Storage6,800 acre-ft
Max Storage6,800 acre-ft
Normal Storage3,300 acre-ft
Surface Area660 acres
Drainage Area10 sq mi
Max Discharge2,400 cfs
Spillway TypeUncontrolled

Ownership & Safety

PurposeRecreation
OwnerCity of Pittsfield
Owner TypeLocal Government
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection04/11/2023
Emergency Action PlanYes

Identifiers

NID IDMA00016
Federal IDMA00016
More InfoState Dam Safety Program

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