Risley Reservoir Dam (no Longer Using 14605)

Risley Reservoir Dam (no Longer Using 14605) is a masonry dam located in Tolland County, Connecticut, built in 1853. It carries a Significant hazard potential classification and has a fair condition assessment.

About Risley Reservoir Dam (no Longer Using 14605)

The primary purpose of Risley Reservoir Dam (no Longer Using 14605) 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 Town Of Manchester (local government). It impounds the Lydall Brook near Lydallville.

The dam stands 28 feet tall and stretches 625 feet across, creates a reservoir covering 14 acres, has a maximum storage capacity of 226 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1853, the structure is one of the older dams in the region, with over a century and a half 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 fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. The most recent inspection on record was 10/15/2024.

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Significant HazardFair ConditionEmergency Action Plan: No

Location

StateConnecticut
CountyTolland
Nearest CityLydallville
River/StreamLydall Brook
Coordinates41.79843, -72.47219

Physical Characteristics

Dam TypeMasonry
NID Height28 ft
Dam Height28 ft
Dam Length625 ft
Year Completed1853 (173 years old)

Storage & Hydraulics

NID Storage226 acre-ft
Max Storage226 acre-ft
Normal Storage226 acre-ft
Surface Area14 acres
Drainage Area0 sq mi
Max Discharge540 cfs

Ownership & Safety

PurposeWater Supply
OwnerTown of Manchester
Owner TypeLocal Government
Hazard ClassificationSignificant
Condition AssessmentFair
Last Inspection10/15/2024
Emergency Action PlanNo

Identifiers

NID IDCT00211
Federal IDCT00211
More InfoState Dam Safety Program

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