Deep Hollow Reservoir Dam

GREAT BROOK· Middlesex, Connecticut· Built 1854· Earth· 28 ft tall
Significant Hazard Water Supply Public Utility

Key Takeaway

Deep Hollow Reservoir Dam is classified as significant hazard in Connecticut. It was completed in 1854 and is 172 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 Length352 ft
Dam TypeEarth
Max Storage255 acre-ft
Normal Storage200 acre-ft
Surface Area28 acres
Drainage Area4 sq mi
Max Discharge509 cfs
Year Completed1854 (172 years old)
NID IDCT00394

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: October 1, 2019
State Regulated: Yes
Regulatory Agency: DEEP

Ownership

Connecticut Water Company

Public Utility

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Deep Hollow Reservoir Dam?

Deep Hollow 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 Deep Hollow Reservoir Dam?

Deep Hollow Reservoir Dam is owned by Connecticut Water Company (Public Utility). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Deep Hollow Reservoir Dam built?

Deep Hollow Reservoir Dam was completed in 1854, making it 172 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 Deep Hollow Reservoir Dam?

Deep Hollow 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 Deep Hollow Reservoir Dam?

Deep Hollow 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 Deep Hollow Reservoir Dam last inspected?

Deep Hollow Reservoir Dam was last inspected on October 1, 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.