The US Army Corps of Engineers Rock Island District is seeking small business concerns capable of providing mechanical dredging services on the Mississippi River in the Sunfish Lake backwater area to create overwintering habitat.
The work consists of, but is not limited to: furnishing all plant, labor material, and equipment necessary for mechanical dredging 230,000 CY of a channel in Sunfish Lake (approximately 12,000 linear feet) and transporting to dredged material placement sites. Only river access is available and hydraulic dredging is not an option.
The channel would have a bottom width of 60 feet and 3H:1V side slopes, with dredging performed to a depth of 584 ft MSL, 8 feet below flat pool elevation. All dredged material shall be placed within an average placement site of 100 feet next to the dredged channel, see attached site plan. The placement site starts at least 30 feet from the dredge channel. An equipment reach capacity of up to 110 feet may be necessary. A rock closure structure (approximately 4200 tons of riprap) will also be constructed to reduce water velocity near the entrance of the backwater area.
The placement sites shall be cleared of trees, stumps, down timber, brush, and other debris above the ground surface that would interfere with placing the dredged material. No clearing of trees with peeling bark greater than 4 inches in diameter shall be allowed between April 1 and September 30 inclusive (the Indiana bat roosting season). The material to be removed is primarily soft to very stiff silts, sands, and clays.
The entire project site is within the Mississippi River and is therefore highly susceptible to water fluctuations that may impact work progress.
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Dredging Today Staff, February 13, 2013; Image: usace