Duck Creek Aqueduct: America's Last Covered Water Bridge

Metamora, Indiana, sits at the edge of one of the great forgotten infrastructure stories of the nineteenth century. Indiana's canal era lasted barely three decades, produced a financial catastrophe for the state, and left behind almost nothing visible to the modern eye. Almost nothing, except for one extraordinary structure that still spans Duck Creek at the edge of this small town: the only surviving covered wooden aqueduct in the United States.

The Duck Creek Aqueduct was built to carry the Whitewater Canal over Duck Creek, so that the canal boat traffic could continue without interruption across the waterway below. Think of it as a covered bridge, but instead of carrying a road, it carries a canal, a trough of water suspended in the air, lined with timber, sealed to hold the weight of the boats passing through it. It is a Burr arch through-truss structure, about ninety feet long, twenty-five feet wide, and twenty-five feet deep, built in eighteen forty-six after the original aqueduct of eighteen forty-three was washed out by a flood.

The Whitewater Canal itself was authorized under Indiana's Mammoth Internal Improvement Act of eighteen thirty-six, one of the most ambitious and disastrous infrastructure bills in any state's history. The act funded a network of canals and roads meant to connect Indiana to national commerce, but construction costs spiraled, financing collapsed, and the railroads arrived just as the canals were finishing. The entire system was functionally obsolete by the eighteen sixties.

The Whitewater Canal ran seventy-six miles, from Lawrenceburg on the Ohio River north to Hagerstown, dropping nearly five hundred feet through fifty-six locks. The aqueduct at Metamora was one of its engineering highlights. After the canal closed, the aqueduct sat, deteriorated, and was restored in the nineteen forties. It was designated a National Historic Landmark in two thousand fourteen.

Today a mill still operates near the aqueduct, powered by the same canal feeder system, and the whole complex functions as a state historic site. A working canal boat still floats through the aqueduct on weekends in season, the only place in the country where you can watch a horse-drawn canal boat pass through a covered wooden water bridge.