The Stevenson Dam on the Housatonic River and Zoar Lake

The dam was erected, by the Connecticut Light and Power Company, to provide water power for generating electricity by hydraulic turbines. It is located on the Housatonic River, the Oxford end being a short distance from the junction of Copper Mine and Freeman Roads, at "river-mile 19.3", and the reservoir is known as "Zoar Lake", being "named after the old settlement of Zoar on the Stevenson side of the river. This settlement, and the bridge which connected it with Oxford, were both inundated by the new reservoir. The reservoir has a drainage area of 1543 square miles. A highway is located on top of the dam and is called Stevenson Bridge.

The maximum base width of the dam (which is a concrete, gravity type structure) is 81 feet, and the maximum height.t6 crest elevation is 122 feet; its length is 1213 feet. It backs up a pond having, at crest elevation, a length of approximately 10 miles.

The power-house is located at the Stevenson side of the dam and the latter has an output capability of 28,750 kilowatts. Four turbo-­generators have been installed, three of 7000 each and one of 7750 K.W. The annual output during a year of average stream flow is 97,650,000 Kilowatt hours, which is said to meet the annual electrical requirements of the town of Oxford, as it is now constituted,
for twenty years.

Work started on the project during the summer of 1917, and the first unit was put into operation Nov. 24, 1919. In 1958, two additional gates were installed at the north (Oxford) end of the dam, in order to increase its spillway capacity, in times of flood; the construction of the Shepaug Dam, further upstream, necessitating the coordination of the spillway capacity of this and the Stevenson Dam.

It is said that when the Stevenson Dam was first projected, the Power Company planned to put the power house at the Oxford end of the dam, but the Town of Oxford objected to this, so the location was changed to the Stevenson end.

From History of Oxford, Connecticut, Litchfield and Hoyt, 1960 (Available for sale by the Oxford Historical Society, Inc., at the Oxford Town Clerk's Office.)