North Grosvenordale Dam

FRENCH RIVER· Windham, Connecticut· Built 1900· Earth· 23 ft tall
High Hazard Recreation Private

Key Takeaway

North Grosvenordale Dam is classified as high hazard in Connecticut. It was completed in 1900 and is 126 years old. Its primary use is recreation. High hazard means loss of life is likely if the dam fails — it does not indicate the dam's current condition. Learn more.

Physical Details

Dam Height 23 ft (taller than 80% in CT)
Dam Length380 ft
Dam TypeEarth
Max Storage840 acre-ft
Normal Storage540 acre-ft
Surface Area60 acres
Drainage Area99 sq mi
Max Discharge4,950 cfs
Year Completed1900 (126 years old)
Year Modified1997
NID IDCT00183

Safety Information

High Hazard

Loss of human life is likely if the dam fails.

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

Emergency Action Plan: Yes
Last Inspection: July 31, 2019
State Regulated: Yes
Regulatory Agency: DEEP

Ownership

929 Riverside Drive LLC;Windham North Properties LLC

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of North Grosvenordale Dam?

North Grosvenordale Dam is classified as High Hazard. Loss of human life is likely if the dam fails. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates North Grosvenordale Dam?

North Grosvenordale Dam is owned by 929 Riverside Drive LLC;Windham North Properties LLC (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was North Grosvenordale Dam built?

North Grosvenordale Dam was completed in 1900, making it 126 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 North Grosvenordale Dam?

North Grosvenordale 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 North Grosvenordale Dam?

North Grosvenordale 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 North Grosvenordale Dam last inspected?

North Grosvenordale Dam was last inspected on July 31, 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.