Upper Unionville Reservoir Dam

HAWLEY BROOK· Hartford, Connecticut· Built 1909· Earth· 23 ft tall
Significant Hazard Recreation Local Government

Key Takeaway

Upper Unionville Reservoir Dam is classified as significant hazard in Connecticut. It was completed in 1909 and is 117 years old. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 23 ft (taller than 80% in CT)
Dam Length220 ft
Dam TypeEarth
Max Storage18 acre-ft
Normal Storage17 acre-ft
Surface Area2 acres
Drainage Area1 sq mi
Max Discharge100 cfs
Year Completed1909 (117 years old)
NID IDCT00267

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: Yes
Last Inspection: September 6, 2019
State Regulated: Yes
Regulatory Agency: DEEP

Ownership

Town of Avon

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Upper Unionville Reservoir Dam?

Upper Unionville 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 Upper Unionville Reservoir Dam?

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

When was Upper Unionville Reservoir Dam built?

Upper Unionville Reservoir Dam was completed in 1909, making it 117 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 Upper Unionville Reservoir Dam?

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

How tall is Upper Unionville Reservoir Dam?

Upper Unionville Reservoir Dam has a dam height of 23 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 Upper Unionville Reservoir Dam last inspected?

Upper Unionville Reservoir Dam was last inspected on September 6, 2019. 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.