The Chippewa Delta: Swinger Slough
Pepin County, Wisconsin
When a fast-moving stream meets a still body of water, or a slow-moving stream, it comes to a halt and deposits its load of sediment in the slow-moving stream. In this way the Mississippi River built the Louisiana Delta over the last seven thousand years. In this way the Chippewa River and all the rivers to run to the Upper Mississippi built their deltas.
The Chippewa deposited so much sand and sediment in the Mississippi that it built a natural dam across the river. Lake Pepin pooled behind it and flooded the river from Wabasha, Minnesota clear to St. Paul. Then the Mississippi itself filled the northern end of Lake Pepin with sediment, creating the mosaic of wooded islands, sluggish sloughs, and lakes that fill the river between St. Paul and Red Wing, Minnesota.
The Chippewa Delta itself is a maze of forested sloughs and small lakes, a region that attracts birds and birders. Wisconsin highway 35 crosses the going north to south when it crosses the Chippewa River. Wisconsin 25 carries you across east to west when it crosses the Mississippi to Wabasha, Minnesota
At the beginning of the twenty-first century, the Chippewa continues to deliver large amounts of sand to the Mississippi through Swinger Slough and other distributaries, so much that the Corps of Engineers has to dredge constantly to maintain the nine-foot channel in the pools downstream from the Chippewa. The engineers have run out of disposal sites for their dredge. Old disposal sites, where the Corps smothered islands in sand, were slow to revegetate. Where the dredge washed back into the Mississippi, it clogged backwaters and secondary channels.
One plan was to use the dredge for island building and preservation, particularly in the sloughs and lakes in the delta that border the Mississippi: Indian Slu and Big Lake, Robinson Lake, Beef Slough, and Riecks Lake.[i]
[i] U.S. Army Corps of Engineers, St. Paul District, “Desired Future Conditions in Pool 4, Mississippi River,” 2-6, http://www.mvp.usace.army.mi./enviro_proection/poolplans/Pool_04