The Detroit District and partnering organizations are ahead of schedule on a dredged material disposal facility, DMDF, promising multiple benefits.
Restoration of the Cat Island chain in Green Bay, Wis., will create a DMDF for placement of non-contaminated material dredged from Green Bay Outer Harbor. At the same time, it will recreate ecologically vital wetlands for the benefit of fish, wildlife and natural vegetation. Additionally, the wave barrier portion will help protect the shoreline from erosion. Completion is expected in early summer 2014 — about six months earlier than projected, with the final cost anticipated to be $22 million, about $5 million lower than expected.
“This project is the benchmark by which all future dredged disposal material facilities shall be measured,” said Corps Project Manager Steve Check. “The cooperation between commercial and environmental interests was paramount to the success of the project.”
Workers are constructing a 4.3-mile-long, eight-foot-high stone wave barrier with five perpendicular dikes, called “legs,” that will separate three cells for disposal of dredged material. Barges will transfer dredged material from Green Bay’s outer harbor either by hydraulic offload or by trucks at the offloading platform.
A gravel road on top of the dike will enable truck transport or pipeline placement of the dredged material to the cells. Over a period of time, the dredged materials will build up the new islands.
Material the Corps dredges from the Green Bay Inner Harbor and inner bay channel will continue to be placed in the Bayport Confined Disposal Facility on the east shore of the bay.
The original Cat Island chain, consisting of Cat, Willow and the Bass Islands, was washed away in the 1960s by high water levels, waves and ice. This effectively wiped out over 1,400 acres of marshland.
The new islands will help coastal marsh areas and underwater plants to thrive and provide 1,440 acres of habitat to various fish and wildlife species, according to the project sponsors, which include Brown County, Wis., the U.S. Fish and Wildlife Service and U.S. Environmental Protection Agency.