The McCartney Lake Project

McCartney Lake, on the Mississippi River near Cassville, Wisconsin, showing dredge cuts made to provide more deep-water habitat. The photo also shows a 22-acre island constructed from the dredged sediments. The dark area inside the island is a 10-acre wetland.


McCartney Lake...to reduce sediment inflow to the system and dredging 8,200 feet of connected channels, about 10 feet deep, within the lake.

The resulting 400,000 cubic yards of dredge material were used to construct a single 22-acre island at the downstream end of the lake to reduce wind-generated waves on McCartney Lake,

...Rather than a barrier island, this was a large island designed to provide a variety of aquatic and terrestrial habitats. Thus, a 10-acre wetland was built on one end of the island and upland habitat at the other end. In addition, because of the large size of the island no shoreline protection was used.

The McCartney Lake project was completed in 1991 and since then, the island has remained stable. Immediately upon completion, dissolved oxygen levels and water depth improved within the dredged areas.

The island was used almost immediately by waterfowl, shorebirds, turtles, amphibians, and small mammals. However, increases in adult fish populations were not evident until six years after project completion due to time lags in fish reproduction and growth.