The U. S. Army Corps of Engineers has awarded a contract to Newt Marine Service of Dubuque, Iowa for repairs to existing chute and backwater projects at Middle Decatur Bend near Decatur in Burt County, Neb. and Hole-in-the-Rock located on the Omaha Indian Reservation north of Macy in Thurston County, Neb.
The proposed projects will repair damages to existing shallow water habitat features caused by the 2011 Missouri River Flood.
Repairs at Middle Decatur Bend will include excavating approximately 88,000 cubic yards of flood-deposited sediment from the existing chute on the west bank of the Missouri River to recreate a 4,300-foot long pilot channel to restore water flow and provide habitat for the endangered pallid sturgeon and other native and aquatic species.
The chute’s inlet will also be lowered by two feet to compensate for bed degradation that has occurred in the adjacent channel of the Missouri River in this area. Lowering the inlet will require the removal and reinstallation of approximately 5,000 tons of riprap.
Scouring in the upstream portion of the chute will be addressed by constructing rock refusal structures. An additional 9,000 cubic yards of material deposited in the chute by the flood will be excavated and placed in the upstream portion to fill in the scour. Rock refusal structures will be constructed in this portion using approximately 1,400 tons of quarried stone, covered with soil, and planted with a native grass seed mixture.
Work on this project is scheduled to begin in mid-October and is expected to be complete by June 2015.
Repairs at Hole-in-the-Rock will include excavating approximately 50,000 cubic yards of material from an existing backwater to re-establish eight acres of shallow water habitat to provide habitat for the endangered pallid sturgeon and other native and aquatic species.
Sediment will be removed from two previously constructed overwintering holes to ensure a water depth of 10 to 12 feet is maintained during the winter months. Bank shaping will also occur to restore the site’s landward and riverward slopes.
Work on this project is scheduled to begin in September and is expected to be complete by June 2015.
[mappress]
Press Release, September 3, 2014