Lake Mattawa Dam South Dam

MIDDLE BRANCH OF SWIFT RIVER· Franklin, Massachusetts· Earth· 10 ft tall
Significant Hazard Recreation Local Government

Key Takeaway

Lake Mattawa Dam South Dam is classified as significant hazard in Massachusetts. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 10 ft (taller than 18% in MA)
Dam Length287 ft
Dam TypeEarth
Max Storage928 acre-ft
Normal Storage438 acre-ft
Surface Area110 acres
Drainage Area2 sq mi
NID IDMA00502

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 5, 2016
State Regulated: Yes
Regulatory Agency: DEPARTMENT OF CONSERVATION AND RECREATION

Ownership

TOWN OF ORANGE, BOARD OF SELECTMEN

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Lake Mattawa Dam South Dam?

Lake Mattawa Dam South 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 Lake Mattawa Dam South Dam?

Lake Mattawa Dam South Dam is owned by TOWN OF ORANGE, BOARD OF SELECTMEN (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

What is the primary purpose of Lake Mattawa Dam South Dam?

Lake Mattawa Dam South 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 Lake Mattawa Dam South Dam?

Lake Mattawa Dam South Dam has a dam height of 10 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 Lake Mattawa Dam South Dam last inspected?

Lake Mattawa Dam South Dam was last inspected on October 5, 2016. 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.