Recurring Operational Drawdown Pool 8, Upper Mississippi River

May 1, 2017

The St. Paul District, US Army Corps of Engineers (Corps), has prepared this preliminary assessment of routine water level drawdowns in Pool 8 for the purpose of improving habitat. This assessment relies on existing information gained from conducting previous drawdowns in this pool and other locations, and information from operating and maintaining the 9 foot navigation project. The intended purpose of the assessment was to provide information needed to plan and initiate a feasibility-type study and National Environmental Policy Act as required by Corps policy prior to the implementation of such a plan for Pool 8. The term “drawdown” used throughout this document means operating the gates at Lock and Dam 8 so that water levels are reduced below the current allowable water levels.