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  • FINAL MAYO CREEK SALT MARSH RESTORATION FEASIBILITY STUDY AND HYDRODYNAMIC

    MODELING

    Prepared For: Town of Wellfleet Ms. Hillary Greenberg 220 West Main Street Wellfleet, MA 02667 Prepared By: Woods Hole Group, Inc. 81 Technology Park Drive East Falmouth, MA 02536 January 2011

  • Final

    Mayo Creek Salt Marsh Restoration Feasibility Study and Hydrodynamic Modeling

    January 2011

    Prepared for: Town of Wellfleet

    Ms. Hillary Greenberg 220 West Main Street Wellfleet, MA 02667

    Prepared by: Woods Hole Group

    81 Technology Park Drive East Falmouth MA 02536

    (508) 540-8080

  • Woods Hole Group

    Final Mayo Creek Salt Marsh Restoration i January 2011 Feasibility Study and Hydrodynamic Modeling 2009-118

    Table of Contents EXECUTIVE SUMMARY .......................................................................................................... 1

    1.0 INTRODUCTION .............................................................................................................. 5

    2.0 MODEL DEVELOPMENT ............................................................................................... 7

    2.1 TECHNICAL APPROACH .........................................................................................................7

    2.2 MODEL CONFIGURATION ......................................................................................................9

    2.3 MODEL CALIBRATION .........................................................................................................19

    2.4 MODEL VALIDATION ..........................................................................................................20

    3.0 EXISTING CONDITIONS .............................................................................................. 22

    3.1 NORMAL TIDES ...................................................................................................................22

    3.2 SEA LEVEL RISE ..................................................................................................................23

    3.3 STORM EVENTS ..................................................................................................................25

    4.0 ALTERNATIVES ............................................................................................................. 27

    4.1 DUCKBILL VALVE REMOVAL ..............................................................................................29

    4.1.1 Normal Tides ........................................................................................................ 29

    4.1.2 Sea Level Rise ....................................................................................................... 32

    4.1.3 Storm Events ......................................................................................................... 34

    4.2 PIPE SIZE ALTERNATIVES ....................................................................................................36

    4.2.1 Normal Tides ........................................................................................................ 37

    4.2.2 Sea Level Rise ....................................................................................................... 39

    4.2.3 Storm Events ......................................................................................................... 42

    5.0 CONCLUSIONS AND RECOMMENDATIONS .......................................................... 44

    6.0 REFERENCES .................................................................................................................. 46

  • Woods Hole Group

    Final Mayo Creek Salt Marsh Restoration ii January 2011 Feasibility Study and Hydrodynamic Modeling 2009-118

    List of Figures Figure 1. Location map of Mayo Creek. The magenta outline shown on the inset of the

    map indicates the extent of the modeling domain and encompasses the area that is less than 10 feet in elevation (NAVD, 1988). ..........................................................6

    Figure 2. 2010 RTK-GPS survey points for Mayo Creek. ....................................................10Figure 3. 2006 Photogrammetry survey points for Mayo Creek. ..........................................11Figure 4. Tide Gauge Deployment Locations. ......................................................................12Figure 5. In-Situ aqua TROLL 200 and Seabird Electronics SBE37 Microcat prior to

    deployment. ............................................................................................................13Figure 6. Barometric pressure and daily rainfall from the Provincetown Airport (KPVC). .14Figure 7. Water Surface Elevation time series for Mayo Creek and Wellfleet Harbor. .......14Figure 8. Salinity time series for Mayo Creek and Wellfleet Harbor. ..................................15Figure 9. Temperature time series for Mayo Creek and Wellfleet Harbor. ..........................15Figure 10. Combined RTK-GPS and Photogrammetry elevation contours. ...........................16Figure 11. Hypsometric curve for Mayo Creek lower basin. ..................................................17Figure 12. Hypsometric curve for Mayo Creek upper basin. ..................................................17Figure 13. Harmonic reconstruction of the Wellfleet harbor tide. ..........................................18Figure 14. Water surface elevation time series for calibration period. ...................................20Figure 15. Water surface elevation time series for validation period. ....................................21Figure 16. Water surface elevation time series for existing conditions, normal tides. ...........23Figure 17. Water surface elevation time series in 2060 for sea level rise scenarios, existing

    conditions. ..............................................................................................................24Figure 18. Water surface elevation time series in 2110 for sea level rise scenarios, existing

    conditions. ..............................................................................................................25Figure 19. MHW and MLW for sea level rise scenarios, existing conditions. .......................25Figure 20. Water surface elevation in Mayo Creek after significant flooding under existing

    conditions. ..............................................................................................................26Figure 21. Mayo Creek Basin Hypsometric curve with mean tide ranges in Wellfleet Harbor

    and Mayo Creek. ....................................................................................................28Figure 22. Mayo Creek Basin with contours of MHW, MLW, and Spring High tide under

    existing conditions (does not consider rainfall). ....................................................28Figure 23. Water surface elevation time series for no duckbill alternative. ............................30Figure 24. Existing tide range, remove duckbill alternative tide range, and Mayo Creek Basin

    hypsometric curve. .................................................................................................31Figure 25. Mayo Creek Basin with contours of MHW, MLW, and Spring High tide, remove

    duckbill alternative. ................................................................................................31Figure 26. Water surface elevation time series in 2060 for sea level rise scenarios, duckbill

    removed alternative. ...............................................................................................32Figure 27. Water surface elevation time series in 2110 for sea level rise scenarios, duckbill

    removed alternative. ...............................................................................................33Figure 28. MHW and MLW for sea level rise scenarios, duckbill removed alternative. ........33Figure 29. Water surface elevation in Mayo Creek after significant flooding comparing the

    duckbill removed alternative and existing conditions. ..........................................35Figure 30. Water surface elevation in Mayo Creek during storm surge in Wellfleet Harbor,

    duckbill removed alternative. .................................................................................36

  • Woods Hole Group

    Final Mayo Creek Salt Marsh Restoration iii January 2011 Feasibility Study and Hydrodynamic Modeling 2009-118

    Figure 31. MHW and MLW versus pipe diameter for pipe size alternatives. ........................37Figure 32. Water surface elevation time series for forty inch pipe alternative. ......................38Figure 33. Existing tide range, forty inch pipe alternative tide range, and Mayo Creek Basin

    hypsometric curve. .................................................................................................38Figure 34. Mayo Creek Basin with contours of MHW, MLW, and Spring High tide, forty

    inch pipe alternative. ..............................................................................................39Figure 35. Water surface elevation time series in 2060 for sea level rise scenarios, 40 inch

    pipe alternative. ......................................................................................................40Figure 36. Water surface elevation time series in 2110 for sea level rise scenarios, 40 inch

    pipe alternative. ......................................................................................................41Figure 37. MHW and MLW for sea level rise scenarios, 40 inch pipe alternative. ................41Figure 38. Water surface elevation in Mayo Creek after significant flooding, comparison of

    40 inch pipe alternative and exi