River “wing dams” pose added risk to boaters

Over the weekend, a popular food boat on the Mississippi struck a wing dam near Clinton, Iowa and sank. For the owners of the boat, they were just trying to maneuver away from a tugboat and barge. And the wing dam under the water just wasn't on their radar. The owner, Sonya Carey-Otte, filmed the whole ordeal on her phone.

Click here to watch Chris Minor's sit-down interview with the owners of the boat

While all aboard got off safely, the barge is still stuck on the wing dam this morning.

For many boaters, a wing dam is just as hazardous as a dam that goes across a waterway. In the Quad Cities, all boaters should familiarize themselves with the "lateral dam" that lies under the water from Arsenal Island, upriver to East Moline. The lateral dam shunts more of the water into the main channel of the Mississippi, toward Lock & Dam 15.

But in Clinton, and many places where there is a need for more than one channel, "wing dams" are built. If you look closely in the satellite view (below) from Google Maps, you can see the wing dam just under the water. This causes more water to flow to the west, away from the main channel of the river. This allows barge traffic to use the municipal docks and the ADM plant, just to the left of this particular vantage point.

Now, think about the fact that the Mississippi River is running high these days. That means the wing dam is not be visible to the naked eye...especially after dark. That can make these navigational hazards much more dangerous. And in this case, it caused a boat and a family's livelihood to sink to the bottom.

The Army Corps of Engineers offers free navigational maps to all boaters. In this sample, you can see the wing dam which makes the channel near the ADM plant navigable.

Click here to look at and print maps so you're familiar with your particular part of the river.

-Meteorologist Eric Sorensen