The dam at Northfield Brook Lake is located 1.3 miles above the brooks confluence with the Naugatuck River. Northfield Brook Lake lies within the boundaries of Thomaston and Litchfield, Conn., with the damsite situated in Thomaston. The reservoir is two miles west of Thomaston on Route 254. The project consists of an earthfill dam with stone slope protection 810 feet long and 118 feet high; a 544-foot-long gated circular concrete conduit with a diameter of three feet; and a chute spillway edged in rock with a concrete weir 72 feet long. The weir’s crest elevation is 15 feet lower than the top of the dam.

The project stores Northfield Brook floodwaters and helps to lower flood stages in downstream communities along the Naugatuck River.

Construction of the dam began in May 1963 and was completed in October 1965. Approximately 1.8 miles of highway were relocated. The cost of the project was $2.9 million. The project has prevented $75.8 million in flood damages since it was built (as of September 2011).

Northfield Brook Lake contains an acre recreation pool that has a maximum depth of 19.5 feet. The flood storage area of the project, which is normally empty and is utilized only to store floodwaters, covers about 67 acres and extends 1.25 miles. The project and associated lands total 235 acres. Northfield Brook Lake can store up to 792 million gallons of water for flood control purposes. This is equivalent to eight inches of water covering its drainage area of 5.7 square miles.

The Reservoir Control Center (RCC) is the "nerve center" for the New England flood control dams such as Northfield Brook Lake. Using radio and satellite communications, the team constantly monitors river levels and weather conditions that influence flood control decisions.

Unlike many other flood control dams in New England Northfield Brook Lake is "self-regulating". The gate is preset to control the desired discharge. If water flows into the reservoir faster than the gate can drain it, the extra water backs up behind the dam. If this inflow exceeded outflow long enough, the stored water would eventually flow over the spillway back into Northfield Brook.

The dam is situated in a scenic area adjacent to the highly industrialized Naugatuck Valley, where public recreational facilities are at a premium. Trout is stocked in the lake, and the grounds contain picnic tables and two group shelters, fireplaces, a beach, hiking trail, and parking and sanitary facilities. Drinking water is also available.

More than 71,000 visitors annually enjoy fishing, picnicking, and hiking at Northfield Brook Lake. Visitors spend an estimated $0.53 million within 30 miles of the lake. An estimated 15 jobs in the local community are supported by visitors to Northfield Brook Dam.

For more information call (860) 283-5540 or visit the website at: Northfield Brook Lake.