READS LANDING — At night, the Mississippi River looks like it's decorated for Christmas at Reads Landing, with a giant string of lights strung for about a quarter mile down the channel and two large, brightly lighted objects above and below.
While striking, those lights are more utilitarian than decorative. They mark a long string of pipes from the Wisconsin shore to the U.S. Army Corps of Engineers Hydraulic Dredge William L. Goetz to a pump station downriver. That station, in turn, connects to the Minnesota shore.
It's pumping sand from a site, called a bath tub, where the corps temporarily stores sand dredged from the main channel. Once the tub fills, it has to be emptied, with that sand going to a giant hole along U.S. 61 in Wabasha, said Dan Cottrell, a corps channel maintenance coordinator from Fountain City, Wis.
The work is the final act of a busy dredging season, he said.
The last towboat pushing barges was expected to leave St. Paul earlier this week. While the river might be open now, winter can roll in quickly, closing the channel with ice. So barge companies tend to pull their boats and many barges out of the region before unpredictable winter slams shut any chance of moving them south.
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When the numbers are tallied, Cottrell expects the corps will have taken about 1.45 million cubic yards of material from the river from St. Paul to Guttenberg, Iowa. That is 63 percent more than the long-term average of 880,000 cubic yards, he said. It's also the most since more than 1.5 million cubic yards were dredged in 1995. Before that, the last time the corps topped that mark was 1974, Cottrell said.
The corps is working at Reads Landing because its dredging work is done for the year, it still has open water and there are few boats of any size on the river. Work won't be done this fall but should be finished in spring, he said.
To do the work, the corps used its major workhorse, the Goetz, along with two other smaller corps dredges and two contracted dredges. It normally only needs the Goetz and two contracted dredges, he said.
This year, the corps needed a sixth in an emergency when commercial traffic couldn't get out of the Prairie du Chien, Wis., harbor, Cottrell said.
The Mississippi was unusually high for more than a year until finally dropping back to normal in late summer. When it's high, it carries a lot of sediment that settles out in slack areas.
Material comes from the Minnesota, Upper Mississippi and Chippewa rivers, said Cottrell. Much of the sand from the Minnesota and Upper Mississippi settles in Lake Pepin but not all. The Chippewa, which enters the Mississippi below Pepin, brings in huge amounts of sand that is known to quickly settle out around Reads Landing, which is just below the Chippewa on the Minnesota side.
When water was high, the corps was busy trying to track down where where sand was settling, though it was a moving target. A sand shoal might move a few miles down the river in days, he said.
"We were trying to stay ahead of that high water," Cottrell said. "I think we survived."
