West Bay Sediment Diversion Work Plan Task 1 : Data Collection and Analysis

1. West Bay Sediment Diversion Work PlanTask 1 : Data Collection and Analysis December 1 2009 Thad Pratt CEERD-HF-FM

2. Data Collection Trips • Data collection Trip 1, March 9-12, 22-23 April, 5-6 May, 2009: Multi-beam and hydrodynamic (ADCP) surveys, bed samples and suspended sediment samples. • Data collection Trip 2, 27-31 May, 2009: Hydrodynamic surveys, suspended sediment samples and additional bed material samples from below Cubit’s Gap to Southwest Pass Jetties. • Data collection Trip 3, June 15-18, 2009: Hydrodynamic surveys and suspended sediment samples. • Data collection Trip 4, July 21-23, 2009: Hydrodynamic surveys, suspended sediment samples, and bed load samples. • Additional Multi-beam survey, August 2009 • Data Collection Trip 5, September 23-24, 2009: Hydrodynamic surveys, suspended sediment samples and bed material samples.

3. Mississippi River Stage & Survey Dates

4. Instrumentation • Geo-Acoustics 250 kHz swath system w/ Applanix POSMV IMU • RDI 600 kHz Broadband ADCP with bottom- tracking and GPS • P-61 point sampler for suspended sediments • Push core & bottom surface drag samplers • OBS and CTD Profiler

5. Multi-beam Survey Coverage

6. Multi-beam Surveys of the West Bay Diversion Cut April Survey August Survey

7. Transect Lines

8. Discharges through the control volume that includes the West Bay Diversion Channel

9. Discharges through the control volume that includes Cubit’s Gap

10. 3D Velocity Mapping Coinciding with Suspended Sediment Samples

11. 3D Velocity Mapping in Vicinity of West Bay Diversion

12. 3D Velocity Mapping Inside West Bay Diversion

13. 3D Velocity Mapping in Vicinity of Cubit’s Gap

14. West Bay Diversion Depth Averaged Velocities April 2009

15. West Bay Diversion Surface Velocity April 2009

16. West Bay Diversion Bottom Velocity April 2009

17. Vertical Velocity Distribution within West Bay Diversion

18. Locations of suspended sediment samples, OBS measurements, and salinity measurements made on May 30, 2009.

19. River Transect just North of Diversion (June 17th)

20. May 29th Survey Range 5.2

21. Suspended Sediment Concentrations

22. Size Classification for TSM Samples/ Depth

23. Drag and Push Core Sediment Samples taken on March 10-12 in vicinity of WB and Cubit’s Gap

24. Drag and Push-core Samples taken on March 10-12, 2009 between Venice, LA and the West Bay Diversion channel.

25. Locations of bottom drag samples made on March 10, 2009 north of Venice, LA.

26. Locations of the bottom drag samples made on May 22, 2009 in Southwest Pass.

27. Bottom Sediment Grain Size Distributions Right Descending Bank Above WBD Left Descending Bank Across from Drag 17

28. Bed Sediment D50 Values Receiving Area

29. Bed Sediment D50 ValuesCubits Gap Area

30. Bed Sediment D50 ValuesSouth West Pass

31. Q and Sediment Flux for Venice to below Cubit’s Gap April 22—23rd Line Total Q Sed Flux M2 (ft³/s) (Tons/Day) R-2.6 444,000 108 K 133 K R-2.8-RB 3,600 0.47 K .8 K R-3.5-RB 2,300 0.4 K .4K R-5.2 518,000 128 K 140K R-6.5-LB 4,700 0.4 K .7K R-6.4-RB 1,700 0.2 K .4K R-12.1 685,600 170 K 191K WBD 51,500 24 K 25k GP 81,000 27 K 50 k BCB 74,000 18 K 22 k 170k 18k 27k 0.4k 0.2k 128k 24k 0.4k 0.47k 108k

32. Q and Sediment Flux Around the Diversion Cut Line Total Q Sed Flux M2 (ft³/s) (Tons/Day) R-5.2 504,000* 153.0 K 162.0 K WBD 42,000* 12.6 K 13.1 K R-4.5 454,000* 144.0 K 148.0 K * Multiple Transects Averaged May 5—6th 153k 12.6k 144k

33. Q and Sediment Flux form Venice to below Cubit’s Gap Line Total Q Sed Flux M2 (ft³/s) (Tons/Day) R-2.6 563,100 263.5K 276K R-2.8-RB 1,375 .157K .1K R-3.5-RB 2,300 .09K .1K R-4.5 675,500 325K 333 K R-5.2 794,400 333.5K 355 K R-6.5-LB 7,000 0.453K .5 K R-6.4-RB 2,400 0.22K .3 K R-9.5 795,000 324K 337 K R12.1 1,003,813 356K 428 K CGRP 11,000 2.8K 3.8 K CGBB 33,200 11K 14.8 K CGOP 17,500 3.7K 4.0 K CGMP 72,000 22K 28 K WBD 72,100 33K 34 K GP 104,600 39K 44K BCB 114,000 57K 50 K May 29—30th 356k 57k 39k 324k 0.453k 0.22k 333 K 33K 22k 11k 3.7k 2.8k 263.5k

34. Q and Sediment Flux form Venice to below Cubit’s Gap June 16—17th 191k Line Total Q Sed Flux M2 (ft³/s) (Tons/Day) R-2.6 385,500 104 K 101 K R-5.2 568,000 145.9K 171 K R-6.5-LB 4,300 0.115 K .175 K R-6.4-RB 600 0.003 K 0 K R-12.1 698,500 191 K 200.0 K CGRP 7,300 0.79 K 1.1 K CGBB 21,000 2.4 K 3.4 K CGOP 9,000 0.9 K 1.1 K CGMP 50,000 5.7 K 8.6 K WBD 51,500 14.3 K 16.0 K GP 74,300 11.9 K 15.7 K BCB 72,100 23.4 K 18.0 K 23.4k 11.8k 0.115k 0.0027k 145.9k 14.3k 5.7k 0.9k 2.4k 0.79k 104k

35. Q and Sediment Flux form Venice to below Cubit’s Gap Line Total Q Sed Flux M2 (ft³/s) (Tons/Day) R-2.6 269,000 14.4 K 14.3 K R-4.5 222,000 10.6 K 9.4 K R-5.2 245,000 13.2 K 13.4 K R-9.5 195,000 12.4 K 11.5 K R12.1 238,000 16.3 K 14.2 K CGRP 2,600 .09 K .1 K CGBB 5,600 .35 K .37 K CGOP 2,400 .06 K .07 K CGMP 24,000 .9 K 1.0 K WBD 28,000 1.8 K 1.5 K GP 29,000 1.4 K 1.7K BCB 51,000 2.9 K 7.9 K July 20__24th 16.3k 2.9k 1.4k 12.4k 13.2 K 1.8K .9k .35k .09k .06k 14.4k

36. Observations • ~45% Total Discharge is lost to the multiple cuts from Venice to below Cubit’s Gap with approximately 50% of the Suspended Sediment leaving the main Channel • Bed material grain size in anchorage range from 0-800 microns • Suspended sediment concentrations range from 50-450 mg/l in the vertical • Grain size in suspended sediments range from 0-100 microns w/ mean size at surface 8-9 microns and w/ mean grain size 1 foot above bed ~15 microns