The Turners Falls Canal completed in 1798 included a log-crib dam across the Connecticut River at the Great Falls. The canal was 2.5 miles long, had 10 locks and a towpath on its eastern shore. Upstream a dam and single-lock canal near the Millers River allowed barges to bypass the French King rapids. By 1802, the canals allowed regular freight traffic from Long Island Sound to Bellows Falls, Vt.
The South Hadley Falls Canal is likely the earliest navigable canal in the United States, with operation starting in 1795 allowing passage around a 53-foot drop in the river by pulling flatboats up an inclined plane of solid stone 275 feet long. Two overshot waterwheels supplied the lifting power.
Completed in 1828, the most southerly of the transport canals built was at Windsor Locks, Conn. At the foot of the canal dam, the tidal waters of Long Island Sound cause the river to rise and fall.
Not all the canals built facilitated transportation. The Holyoke Canal was a power canal and dates to 1827 when a simple wing dam at the Great Rapids fed water to a canal that powered a cotton cloth mill. In 1848 investors realized there were waterpower enough for 450 mills and construction of the modern canal network began. To divert water into the canals, a timber crib dam 1,000 feet in length was constructed across the river. It failed within hours of completion, immediately replaced by a stronger timber dam and eventually by a granite-faced dam in 1900.
Before people foresaw the coming of the railroads, legislatures chartered some rather grandiose canal plans. Chartered in 1830, one planned to avoid the stiff flow through the "chute" below the Hinsdale, N.H. Bridge. In 1797, the Vt. Legislature chartered the exclusive right to put locks in the White River from its mouth up to the Royalton Meeting House but inactivity forced Elkanah Stevens to forfeit it. In 1830, a canal if built would connect the Wells River, going over the Green Mountains to Montpelier and then down the Winooski River to Lake Champlain. The canal links totaled 72 miles. Another canal planned to reach from the Merrimac River near Concord, N.H. up the Pemigewassett River to Wentworth and then across to the Connecticut River at Haverhill, N.H. Fanciful drawings from 1816 show a canal stretching from the Merrimac River at Concord to the Sugar River in Claremont, N.H.
The last two and most grandiose unfulfilled canal plans would build one up the Deerfield Valley through the 25,031 foot long Hoosac Tunnel to Troy, N.Y., there to connect with the Erie Canal and reach all parts of the country. The other grand plan was a canal from the mouth of Millers River near Greenfield, Mass. to Boston. Before all of these plans could reach their goal, along came railroads leaving these canals un-built and those built in rapid decline.
From the 1700s, the Connecticut has been a working river. Each dam associated with the canals did immense environmental damage not addressed until the 1950s with the beginning of the construction of facilities to allow some aquatic species to bypass the dams. That work continues to this day.
David L. Deen, River Steward for the Connecticut River Watershed Council celebrating over 60 years as a protector of the Connecticut River.