Colby Brook Dam

COLBY BROOK· Rockingham, New Hampshire· Earth· 11 ft tall
Low Hazard Recreation Private

Key Takeaway

Colby Brook Dam is classified as low hazard in New Hampshire. Its primary use is recreation.

Physical Details

Dam Height 11 ft (taller than 23.8% in NH)
Dam Length260 ft
Dam TypeEarth
Max Storage94 acre-ft
Normal Storage50 acre-ft
Surface Area16 acres
Drainage Area9 sq mi
Max Discharge926 cfs
Year Modified1982
NID IDNH00740

Safety Information

Low Hazard

No probable loss of human life and low economic/environmental losses expected.

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

Emergency Action Plan: No
Last Inspection: May 21, 2020
State Regulated: Yes
Regulatory Agency: NH DES

Ownership

BERKSHIRE DOMINION HOLDINGS LLC

Private

Nearby Dams

Country Pond Dam

Rockingham, NH

Unknown 6 ft

Dimond Pond Dam

Rockingham, NH

Unknown 12 ft

Powwow Pond Dam

Rockingham, NH

Significant Hazard 12 ft

Little Cub Pond Dam

Rockingham, NH

Low Hazard 11 ft

Frye Pond Dam

Essex, MA

Significant Hazard 10 ft

Exeter River Dam

Rockingham, NH

Significant Hazard 15 ft

Bodwell Septage Facility Dam

Rockingham, NH

Significant Hazard 9 ft

Lake Pentucket Dam

Essex, MA

Significant Hazard 8 ft

Frequently Asked Questions

What is the hazard classification of Colby Brook Dam?

Colby Brook Dam is classified as Low Hazard. No probable loss of human life and low economic/environmental losses expected. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Colby Brook Dam?

Colby Brook Dam is owned by BERKSHIRE DOMINION HOLDINGS LLC (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

What is the primary purpose of Colby Brook Dam?

Colby Brook 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 Colby Brook Dam?

Colby Brook Dam has a dam height of 11 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 Colby Brook Dam last inspected?

Colby Brook Dam was last inspected on May 21, 2020. 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.