The Quoddy Dam Model Museum houses a working scale model of the Passamaquoddy Bay Tidal Power Project which was built for the original project. The model, formed of concrete and weighing thousands of pounds, shows the locations of the proposed dikes and gates, as well as the turbine-powered generating station. When operating, you can observe how the tides flow into the area's bays, and how these tides could have been harnessed to generate electricity.
Passamaquoddy Bay is an inlet of the Bay of Fundy, between the U.S. state of Maine and the Canadian province of New Brunswick, at the mouth of the St. Croix River. Most of the bay lies within Canada, with its western shore bounded by Washington County, Maine. The southernmost point is formed by West Quoddy Head on the U.S. mainland in Lubec, Maine; and is then bounded northeastwardly by Campobello Island, New Brunswick and Deer Island, New Brunswick; thence, running to shores by mainland Charlotte County, New Brunswick.
A proposed development project for eastern Maine, envisioned by hydroelectric engineer Dexter Cooper, involving the construction of a tidal harness for electricity generation was initiated in 1935 under U.S. Public Works Administration funding and with the blessing of President Franklin Delano Roosevelt, whose summer home was on nearby Campobello Island, New Brunswick, Canada.
Also known as the Quoddy Project, it proposed impounding Cobscook Bay and part of Passamaquoddy Bay with a series of dams and control structures to exploit the resulting water level difference to generate electrical power. The electric turbines for power generation would have been located at the isthmus on Moose Island, Eastport, with the water passing between Passamaquoddy Bay and Cobscook Bay, with the "used" generating water released from impoundment at low tide.
Part of this project was completed by the construction of dikes built between Pleasant Point-Carlow Island-Moose Island. The project was suspended one year later after the United States Congress refused further funding, thus the actual barrier dams never being built. The dike barriers now underlie the former Maine Central Railroad and the current Maine Highway 190, as well as between Treat Island (in Eastport) and Dudley Island (in Lubec, Maine).
Several iterations and variations on the project later ensued, but never began construction.