A U.S. Army Corps of Engineers’ mechanical dredge pulls clay out of Andalusia (Ill.) Harbor to make it 6 feet deep throughout the harbor. It’s one of several dredging projects under way in the Quad-City area to make the going easier for boaters. Gary Kramer

Dredging projects under way by the U.S. Army Corps of Engineers will have an impact on Quad-City area boaters. 

Some were done last fall, some this spring and others are planned for later this summer, fall or next spring.

Nicole Manasco, channel maintenance coordinator for the Corps, says money became available for some of these projects through a Western Illinois Small Boat Harbor appropriation from the federal government.

Last fall, while dredging in the Princeton Beach area, the Corps was able to use the beach for “bankline placement” and deposited as much material there as the crews could. That significantly added to the amount of sand there. Downstream, a smaller amount of material was added to the bankline at Buffalo Shores.

This spring, crews followed up an unsuccessful attempt last year at dredging the mouth of Andalusia Harbor near Andalusia, Ill. They not only completed that task, but ended up dredging much of the entire harbor.

The original contractor for that job dredged hydraulically. The contractor ran into difficulty because the material to be removed from the mouth of the harbor was compacted clay, which was different from what was expected. He removed as much as he could, but that amount was not enough to create the new depth the Corps expected.

The Corps sent in its own crews this spring to mechanically dredge. They used barges with a crane on top that drew quite of bit of water. In order to position that equipment to dredge in certain places, they had to dredge the area first so they could maneuver their gear. The result was they ended up dredging the entire harbor to 6 feet at normal pool, except underneath the upstream docks. The material removed was taken 12 miles downstream by barge and deposited at a bank location there.

In Moline, Manasco says they will start dredging the entrance to Marquis Harbor within the next month. Before work can begin there, the city has to provide a spot for placement of the dredged material. The city was not expecting this project at this time, so they are scrambling to get all the necessary permits and meet all the requirements. The plan is to dredge an 80-foot wide by 400-foot long area at the harbor’s entrance.

The other local project that is being funded is a study of a dike at the upstream entrance to Sunset Marina. A study about that had been previously done but at that time, funding was to come from Rock Island.

As funding shifts to the federal government, there are different criteria that need to be met so the project needs to be re-examined from a different cost-analysis perspective. All of this follows an earlier joint study by the Corps and the city that determined a dike would be the best way to keep further siltation from entering the harbor, especially during periods of high water.

Some dredging was done within the marina within the last two years, so there are no plans for further work there at present. However, if the dike does not meet the cost-effective criteria now required, it is possible that funds for the dike project could be used for dredging within the harbor.

Other areas the Rock Island District Corps office is concentrating on are dredging parts of the Art Keller Marina in Quincy, Ill., and a section of Quincy Bay, which may not get under way until next spring.