Roscoe, South Dakota. Eastern North and South Dakota once contained thousands of sloughs. After European-American settlement, the area became known as the prairie-pothole region.
The potholes, or sloughs, acted as natural reservoirs, storing snowmelt and rainwater. When full, they attracted fish, ducks, geese, muskrats, frogs, toads, and beaver. Herds of bison also gravitated to the sloughs, to graze on the luxurious grasses growing along their edges or to drink their fresh water. When temperatures became too hot, the bison wallowed in the potholes to cool their large, woolly bodies.
In the late 19th century, farmers began draining the sloughs in order to plant more wheat, corn, and soybeans. The loss of the potholes, and their natural reservoir storage capacity, partly explains why the rivers and streams of the northern plains now experience higher flood stages and more frequent floods.
Today, on South Dakota State Highway 12 between Roscoe and Ipswich, the roadway narrows to one lane as it passes through the center of a large slough. The recent rains have pushed the slough way beyond its regular borders. Sparkling blue water laps over one lane of Highway 12, while threatening to submerge the single lane still open to traffic. Although this recently enlarged wetland has become a traffic nuisance, it is a blessing for those living in the Missouri Valley because without it more floodwater would be flowing down the Missouri River.
If we want a safe, effective, and non-technical means of curtailing floods across the Midwest, restoring the potholes of the eastern Dakotas is a good place to start. Such a restoration project would also be a boon to fish and wildlife, hunters and fishers, and the physical and mental well-being of local residents.