Risley Reservoir Dam

LYDALL BROOK· Tolland, Connecticut· Built 1853· Masonry· 28 ft tall
Significant Hazard Water Supply Local Government

Key Takeaway

Risley Reservoir Dam is classified as significant hazard in Connecticut. It was completed in 1853 and is 173 years old. Its primary use is water supply. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 28 ft (taller than 85.5% in CT)
Dam Length625 ft
Dam TypeMasonry
Max Storage226 acre-ft
Normal Storage226 acre-ft
Surface Area15 acres
Drainage Area1 sq mi
Max Discharge540 cfs
Year Completed1853 (173 years old)
NID IDCT00211

Safety Information

Significant Hazard

No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: No
Last Inspection: October 2, 2014
State Regulated: Yes
Regulatory Agency: DEEP

Ownership

Town of Manchester

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Risley Reservoir Dam?

Risley Reservoir Dam is classified as Significant Hazard. No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Risley Reservoir Dam?

Risley Reservoir Dam is owned by Town of Manchester (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Risley Reservoir Dam built?

Risley Reservoir Dam was completed in 1853, making it 173 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.

What is the primary purpose of Risley Reservoir Dam?

Risley Reservoir Dam serves the following purposes: Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Risley Reservoir Dam?

Risley Reservoir Dam has a dam height of 28 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.

When was Risley Reservoir Dam last inspected?

Risley Reservoir Dam was last inspected on October 2, 2014. Inspection dates indicate when a formal review occurred, not the results of that inspection.

Data from the National Inventory of Dams (NID) maintained by the US Army Corps of Engineers. Dam conditions may have changed since the last update. This site is not affiliated with USACE. Do not use for emergency planning — contact your local dam safety program.