USACE creating new islands near Grafton, Illinois

The U.S. Army Corps of Engineers, St. Louis District’s Dredge Potter is currently working near Grafton, Illinois, between river miles 218 and 222, using a 300-foot-long flexible floating pipeline to remove material from the navigation channel.

The flexible pipeline allows for the creation of ephemeral islands that will be used for habitat restoration and mimics natural sand bar formation.

The St. Louis District advised recreational boaters to use caution around newly created islands near Grafton. Due to rising water levels and since the dredge placement is unconfined using the energy of the river to distribute the sediment and shape the bar, these newly created ephemeral islands or sandbars may be underwater or unstable and it is recommended that boaters avoid these temporary islands.

A variety of fish and wildlife benefit from these temporary, or ephemeral, islands and sandbars. Ephemeral islands, when exposed, provide safe feeding and resting habitat for a variety of shorebirds.

If exposed for long periods during the breeding season, these sand bars may also provide nesting habitat for species like the Interior Least Tern. When these temporary islands are underwater they provide habitat for species of minnows and young fish.