Across the country’s flood-battered midsection, the farms, towns and homes consumed by the bloated waters have drawn much of the attention. But flooding has had another, less intuitive effect — crippling the nation’s essential river commerce. Water, the very thing that makes barge shipping possible in normal times, has been present in such alarming overabundance this spring that it has rendered river transportation impossible in much of the United States.

The Arkansas River has been closed to commercial traffic. So has the Illinois River, a key connection to Chicago and the Great Lakes. And so has part of the Mississippi River near St. Louis, where it crested on Sunday at its second-highest point on record, cutting off the river’s northern section from shippers to the south.

As a result, farmers already grappling with flooded fields and worries about the trade war with China have struggled to obtain fertilizer for their crops. Customers have seen their deliveries of construction materials and road salt get stuck midway to their destinations. And shippers have made drastic cuts to their operations with work at a standstill.

“It’s like when you’re driving on an interstate and there’s an accident in front of you and there’s nowhere to go,” said Jeff Webb, president of Cargill Marine and Terminal, which operates more than 1,400 barges, hundreds of which are now stuck in the Gulf of Mexico or lower Mississippi River because of closures to the north.