Another new mitigation project along the Missouri River in Nebraska is currently underway on and near Boyer Chute NWR.
The Boyer Bend Billabong/Lower Calhoun Chute project is being done at a cost of $3.818 million dollars, using federal funds provided through a congressional allocation to the Army Corps of Engineers.
The project is for the benefit of the endangered Pallid Sturgeon, according to Matt Krajewski, Corps project manager.
This and other sites are selected through an extensive review and selection process, to include a review of historic maps and aerial photos showing the location of former riverine habitats. River engineers were also involved in the site selection process.
"This project meets the goals of mitigation without hindering the authorized uses of the river, including navigation and water supply," Krajewski said.
Project components include dredging an 11-acre chute and a 39-acre backwater along the west bank of the Missouri River at Boyer Chute Island, about 1.5 miles north of the south end of Boyer Chute along the west river bank.
The Lower Calhoun Chute project site north of Boyer Chute, has been designed to include multi water-levels of variable depths. The plan is to provide water habitat that will emulate conditions which occurred historically with the spring rise in the level of the water and the spreading of the channel into side channel backwaters and sloughs.
"This project will create habitat diversity by introducing historic water depths and velocities to the river channel," Krajewski said. "The Corps has been working with state and federal partners for years to develop viable projects, and this project is now underway after several years of planning and work with project partners. We worked closely with refuge staff to agree on a mutually acceptable project."
Krajewski explained that this project is one of many completed by the Corps as part of a biological opinion. It required creating a particular amount of habitat connected to the river, with water less than 5 feet deep and a flow less than 2 feet per second.
Projects have been done during the past two decades in order to mitigate for the ecosystem diversity prevalent along the Missouri River before it was channelized.
Clearing and grubbing - removing trees and getting rid of debris - is currently underway at the site of the billabong.
Equipment is being moved in via river barges rather than being transported across refuge lands. "This effectively minimizes disruption to habitats and wildlife," said Krajewski.
The project will be completed by March 2010.
The Lower Calhoun Chute billabong project site is shown along the west river-bank on the right side of the aerial photograph. A billabong is known as a "a stagnant backwater or slough formed by receding floodwater."