1. 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

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

3. BUILDING STRONG ® Fuse Plug Levee

4. BUILDING STRONG ® Birds Point – New Madrid Floodway  Constructed in 1928 in response to the flooding experienced in 1927.  Activated only once before 2011 – 1937

5. BUILDING STRONG ® 0 62.5 – Project Design Flood EL. 333.0 EL. 270.5 60.0 – 100 Yr Event 58.5 – 50 Yr Event329.0 330.5 56.0 – 25 Yr Event326.5 52.3 – 10 Yr Event322.8 49.3 – 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’

6. BUILDING STRONG ® Floodway Activation  Video of Detonation: ► http://www.youtube.com/watch?v=RfIII1Fovqc&feature=relmfu http://www.youtube.com/watch?v=RfIII1Fovqc&feature=relmfu  Video of Flow filling Floodway ► http://www.youtube.com/watch?v=Xz3LIeBhkYs http://www.youtube.com/watch?v=Xz3LIeBhkYs

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

8. BUILDING STRONG ® Concentrated Flow

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

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

11. 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

12. 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

13. BUILDING STRONG ® Environmental Complication Protect Fill Separate

14. 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

15. 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

16. BUILDING STRONG ® Sediment Curtain Install

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

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

19. BUILDING STRONG ® Dredged Fill

20. BUILDING STRONG ® ?QUESTIONS?