Loch Lyall Dam

Loch Lyall Dam is a concrete dam located in Putnam County, New York, built in 1950. It carries a Significant hazard potential classification and has a poor condition assessment.

About Loch Lyall Dam

The primary purpose of Loch Lyall Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Amor Towles (private). It impounds the Indian Brook near Nelson Corners.

The dam stands 11 feet tall and stretches 400 feet across, creates a reservoir covering 19 acres, and has a maximum storage capacity of 98 acre-feet. Completed in 1950, the structure is well-established, with more than 75 years of service.

This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in 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 01/24/2025.

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Significant HazardPoor ConditionEmergency Action Plan: Yes

Location

StateNew York
CountyPutnam
Nearest CityNelson Corners
River/StreamIndian Brook
Coordinates41.41556, -73.90722

Physical Characteristics

Dam TypeConcrete
NID Height11 ft
Dam Height11 ft
Dam Length400 ft
Year Completed1950 (76 years old)

Storage & Hydraulics

NID Storage98 acre-ft
Max Storage98 acre-ft
Normal Storage60 acre-ft
Surface Area19 acres
Max Discharge190 cfs
Spillway TypeUncontrolled

Ownership & Safety

PurposeRecreation
OwnerAmor Towles
Owner TypePrivate
Hazard ClassificationSignificant
Condition AssessmentPoor
Last Inspection01/24/2025
Emergency Action PlanYes

Identifiers

NID IDNY01201
Federal IDNY01201
More InfoState Dam Safety Program

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