US Army Corps of Engineers BUILDING STRONG ® Repairing the Mississippi River Levee with Dredged Material after the Historic 2011 Flood Dredging 2012 Shane Callahan, P.E. Michael Clay, P.E. Memphis District October 24, 2012

BUILDING STRONG ® Birds Point – New Madrid Floodway 33 miles long 10 miles wide 205 sq. mi. Inflow # 1 Inflow/Outflow # 1 Inflow/Outflow # 2

BUILDING STRONG ® Fuse Plug Levee

BUILDING STRONG ® Birds Point – New Madrid Floodway  Constructed in 1928 in response to the flooding experienced in  Activated only once before 2011 – 1937

BUILDING STRONG ® – Project Design Flood EL EL – 100 Yr Event 58.5 – 50 Yr Event – 25 Yr Event – 10 Yr Event – 5 Yr Event319.8 Flood of Record 1937 – 59.5’ 1997 – 56.2’ > 1973 (55.7) 2008 – 53.9’ Cairo Gage 2002 – 55.0’ 2005 – 53.2’ 2011 Flood 61.72’

BUILDING STRONG ® Floodway Activation  Video of Detonation: ►  Video of Flow filling Floodway ►

BUILDING STRONG ® Less Powerful Blasting Agent  Lack of Broad overflow

BUILDING STRONG ® Concentrated Flow

BUILDING STRONG ® Scour Hole Formation  12.5 acre, 50’ deep scour hole  Over 450,000 CY of displaced material

BUILDING STRONG ® Floodway Activation  Side by side comparison of aerial photography before activation and soon/directly after activation

BUILDING STRONG ® Repairing the Levee  Sand and sediment surrounding the area were pushed into scour hole – too slow  A faster approach to filling the scour hole was required

BUILDING STRONG ® Dredging Proposed  Dredge Iowa ► Hull length = 194 ft ► Hull width = 32 ► Ladder = 76 ft ► Cutter Brake H.P. = 300 HP  Average Dredge Fill Rate: 20,000 CY/day

BUILDING STRONG ® Environmental Complication Protect Fill Separate

BUILDING STRONG ® Environmental Complication  Blue Hole contamination  Original containment proposal involved a rock/rip-rap dike ► $2 million + ► 3 months or more ► Potentially ineffective sediment containment system

BUILDING STRONG ® Environmental Solution  Sediment Curtain ► 2 week lead time ► 3 day installation time ► Approx. $50,000 ► Virtually impenetrable to sediment Blue Hole Scour Hole

BUILDING STRONG ® Sediment Curtain Install

BUILDING STRONG ® Begin Dredged Fill Dredge Blue Hole Dredged Fill Area to be Filled

BUILDING STRONG ® Begin Dredged Fill Blue Hole Dredged Fill Area to be Filled Incoming Slurry Pumped Drain

BUILDING STRONG ® Dredged Fill

BUILDING STRONG ® ?QUESTIONS?