1. Technical Support in Engineering Construction Phase of Craney Island Eastward Expansion Mac Sisson, Harry Wang, Jian Shen, Albert Kuo, and Wenping Gong VIMS Numerical Modeling Group Gloucester Point, VA January 2008

2.  Introduction and Background

3. Proposed Norfolk Harbor Dredging by Navy Proposed Craney Island Eastward Expansion APM Dredged Channel and Terminal

4. Modified CIEE Design -500-foot westward shift of face of wharf -Areal decrease from 539 acres to approx. 500 acres Face of wharf (2001 footprint) Face of wharf (2007 footprint)

5. OUTLINE Model Grid Revision and Evaluation - In accordance with the expansion design modification, the HEM-3D model’s orthogonal grid required revision Impact on water quality – historical data analysis - salinity, temperature, TSS, chlorophyll, and DO - nitrogen and phosphorus concentrations Impact on sediment dynamics – SSFATE

6. Reason: The model grid required revision in accordance with the change of the expansion area design to place the face of the wharf a full 1000 feet from the westernmost toe of the channel (a shift of 500 feet to the west). Action: It is important to evaluate this revision by comparing thoroughly the results from the new grid with those from the original grid that has been fully calibrated and verified. The comparison has been done at 22 locations (CBP stations of Lower James and Elizabeth Rivers) for the 4-month period of intensive surveying of year 2000. Part I: Model Grid Revision and Evaluation

7. Old Grid - 500 feet from face of wharf to westernmost toe of channel - 539 acres of expansion New Grid - 1000 feet from face of wharf to westernmost toe of channel - Approx. 500 acres of expansion GRID CONFIGURATIONS

8. -A full-blown 3D sediment model -Processes including resuspension, transport, and deposition of cohesive and noncohesive sediments -Settling of cohesive sediments modeled as a function of aggregation and settling -ECOMSED has been interfaced with the VIMS HEM-3D model ECOMSED Sediment Modeling

9. Additional Data Received for Further Refinement of ECOMSED Modeling for the Project (1) Lab results of shear strength measurements from core samples taken at depths over the top 1 meter (2) In the absence of shear stress measurement data, fine-scale vertical profiles of both porosity and density

19. Part II: Water Quality Data Analysis Water Quality Data Analysis in the Elizabeth River For the last 5 years (from 2001- 2005) - Nitrogen concentrations increase - Bottom dissolved oxygen decreases For the 15-year period from 1993-2007, there does not appear to be a trend The exact status of DO impairment in the Elizabeth River needs further clarification from DEQ

20. LE5. 2 LE5. 3 LE5. 4 LE5. 5

21. LE5.6

23. ELI2

25. ELD01

27. ELE01

37. Integrated Modeling Approach Hydrodynamic Model Watershed Model Water Quality Model (Include Water Column, Sediment, and Ecosystem Processes) Sediment Fluxes Transport Sediment Model Nutrient Loads Freshwater Discharge Field Data Collection

38. Source of Elizabeth River watershed loading: EPA Chesapeake Bay Program, Phase V watershed model

40. Watershed nutrients loading from Chesapeake Bay Watershed Model Phase IV results (17-year average, from 1984 to 2000)

41. Long-term Hydrodynamic and Water Quality Simulations Base CaseProject Case Future plus Cumulative Case Existing conditions (includes APM Terminal Channel) Existing conditions with the Eastward Expansion Eastward Expansion plus future projects (i.e., Navy dredging, 3 rd Crossing)

42. a. Lab work on sediment samples Seven transmitted samples have been sub- sampled. Moisture content and fraction greater than 0.250 mm have been determined. Sub-samples have been dispersed in preparation for setting tests. Settling tests will be initiated. Sand fractions greater than 0.150 mm and 0.074 mm, loss of ignition, and dispersed grain size will be determined. Part III: SSFATE Modeling

43. b. Modeling Approach SSFATE has been linked with the HEM-3D grid and 5 days of hydrodynamic output from September 1978. Two example scenarios have been constructed for point source releases near the expansion site. Model validation using additional 1978 data from the Elizabeth River will be conducted. The source term for the model validation will be constructed using both the TGU concept and an analytical model developed for a cutterhead dredge to assess the difference in the two methods.