The US Army Corps of Engineers (USACE), Rock Island District (District), requests your review of the Environmental Assessment (EA) titled, Marais D’Osier Slough Beneficial Use Placement Project (Project) dated December 2024. The District is interested in your review and comments regarding the alternative analysis and the preferred alternative for this project to fulfill the requirements of the National Environmental Policy Act.
The draft EA is available for public review from December 19, 2024 to January 28, 2025. Comments may be submitted via email to: CEMVR_Planning@usace.army.mil, or by writing to the address below with the title of the Project.
To request a paper copy or CD, contact the District’s Environmental Planning Branch at 309-794-5231, email CEMVR_Planning@usace.army.mil, or write to:
Department of Army
U.S. Army Corps of Engineers, Rock Island District
Attn: Meden (PD)
Clock Tower Building
P.O. Box 2004
Rock Island, IL 61204-2004
PROJECT INFORMATION
In order to meet increasing demands for more dredged material placement capacity, the District proposes using additional opportunities for beneficial use (BU) placement around Mississippi River miles (RM) 508.0 to 511.5 in Pool 14. The BU opportunities for the District’s Operations and Management would need to meet criteria for environmentally acceptable placement and operationally feasible placement in order to be considered a reasonable alternative for future dredged material placement. Additional BU placement sites would expand the life of other placement sites within Pool 14 the Mississippi River. Without addressing alternative improvements to this system, potential overflow challenges may occur in the lower extent as a result of major rainfall events.
Nationwide, USACE is seeking to maximize BU placement opportunities on all federally-managed navigable deep draft and shallow draft channels. Currently, the District places dredged material along the navigation channel on bankline, thalweg, and upland locations within environmentally-cleared reaches of the Pool 14 of the Mississippi River. BU placement in Pool 14 is limited. Expanded BU site capacity ensures placement opportunities for O&M of the 9-foot navigational channel.
ALTERNATIVES CONSIDERED
1. No-Action Alternative (Alternative A)
2. Preferred Alternative, (Alternative B) of placing dredged material at proposed quarry sites in Pool 14.
PREFERRED ALTERNATIVE
The preferred alternative is for establishing new BU placement sites in three quarry sites off the mainstem channel along the left descending bank at RM-508; RM-510.1, RM-510.4. Dredging and placement activities would only occur as needed to maintain authorized navigation channel depths, similar to the No Action Alternative. The District would place dredged material by either mechanical or hydraulic methods. The Steamboat Slough bankline and thalweg placement sites would continue to be used for placement of dredged materials.
Click the link below to access the project documents.