Upper Mianus River Dam

MIANUS RIVER· Fairfield, Connecticut· Built 1930· Masonry· 3 ft tall
Significant Hazard Recreation Private

Key Takeaway

Upper Mianus River Dam is classified as significant hazard in Connecticut. It was completed in 1930 and is 96 years old. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 3 ft (taller than 0.7% in CT)
Dam Length60 ft
Dam TypeMasonry
Max Storage72 acre-ft
Normal Storage72 acre-ft
Surface Area18 acres
Drainage Area70 sq mi
Max Discharge810 cfs
Year Completed1930 (96 years old)
NID IDCT01703

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
State Regulated: Yes
Regulatory Agency: DEEP

Ownership

Ruth Spelke Est

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Upper Mianus River Dam?

Upper Mianus River 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 Mianus River Dam?

Upper Mianus River Dam is owned by Ruth Spelke Est (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Upper Mianus River Dam built?

Upper Mianus River Dam was completed in 1930, making it 96 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 Mianus River Dam?

Upper Mianus River 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 Mianus River Dam?

Upper Mianus River Dam has a dam height of 3 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.

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.