WETLAND RESTORATION  IN SAN FRANCISCO BAY  John A. Bourgeois Wetland Ecologist California State Coastal Conservancy  and H...
<ul><li>Surrounded by over 7 million urban residents </li></ul><ul><li>Drains approximately 40% of California’s lands </li...
 
“ A good day’s bag.”
 
Acres x 1000 Open Bay (<MLLW) Intertidal (tidal flat and marsh)  Ca 1850
Acres x 1000 Open Bay (<MLLW) Intertidal (tidal flat and marsh) 2000
Wetlands Past and Present ca. 1850 ca. 1998
<ul><li>1860-1930: over 350,000 acres diked for farmland </li></ul><ul><li>Gold rush era: urban development and increased ...
© David Sanger
 
 
Wetlands defined <ul><li>Wetlands are defined by three characteristics: hydrology, soils, and vegetation. </li></ul>Ecosys...
Wetland Functions <ul><li>Fish and wildlife habitat </li></ul><ul><li>Water quality improvement </li></ul><ul><li>Flood st...
Morphological Adaptations
Physiological Adaptations <ul><li>Excreting salt crystals (cordgrass) </li></ul><ul><li>Retaining water (pickleweed) </li>...
Endangered Species  (in San Francisco Bay) <ul><li>California Clapper Rail </li></ul><ul><li>Salt marsh harvest mouse </li...
San Francisco Bay: Mixed Semi-Diurnal Tides When there are two high tides each day but with different heights (and two low...
Tidal Prism: The volume of water that flows into and out of an estuary in one tidal cycle.
Subsidence <ul><li>Tidal marshes are in a dynamic equilibrium, and rely on constant sediment input. </li></ul><ul><li>Salt...
Why Restore the South Bay? Docent-led Interpretive Tour Least Sandpipers 1983 Alviso Floods
Regional Planning Efforts
 
Salt Pond  Acquisition © Mark Rauzon © Cargill Salt
Cost of Acquisition <ul><li>16,500 total acres </li></ul><ul><ul><li>15,100 in South Bay </li></ul></ul><ul><ul><li>1,400 ...
 
Ecological Trade-offs <ul><li>Tidal Marsh species vs. Salt Pond species </li></ul>
 
Wetland Restoration 101 <ul><li>Restore tidal action by breaching levees at historic slough locations </li></ul><ul><li>En...
Narrow strip marshes do not allow for complex channel development Abrupt levee transitions do not provide high tide refugi...
 
 
 
 
<ul><li>H.T. Harvey & Associates </li></ul><ul><ul><li>Aerial photos by Karen Verpeet </li></ul></ul><ul><li>Philip Willia...
<ul><li>Preliminary Design Concept </li></ul><ul><li>Combine scientific, cultural and recreational components </li></ul><u...
 
 
 
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Wetland Restoration in San Francisco Bay

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Wetland Restoration in San Francisco Bay

  1. 1. WETLAND RESTORATION IN SAN FRANCISCO BAY John A. Bourgeois Wetland Ecologist California State Coastal Conservancy and H. T. Harvey & Associates
  2. 2. <ul><li>Surrounded by over 7 million urban residents </li></ul><ul><li>Drains approximately 40% of California’s lands </li></ul><ul><li>Encompasses about 1,600 square miles </li></ul><ul><li>The largest estuary on the west coast of North and South America </li></ul>San Francisco Bay Features © David Sanger
  3. 4. “ A good day’s bag.”
  4. 6. Acres x 1000 Open Bay (<MLLW) Intertidal (tidal flat and marsh) Ca 1850
  5. 7. Acres x 1000 Open Bay (<MLLW) Intertidal (tidal flat and marsh) 2000
  6. 8. Wetlands Past and Present ca. 1850 ca. 1998
  7. 9. <ul><li>1860-1930: over 350,000 acres diked for farmland </li></ul><ul><li>Gold rush era: urban development and increased sediment delivery to the Bay </li></ul><ul><li>Post-WWII: more urban development, flood control projects, salt pond development </li></ul>History of Land Loss
  8. 10. © David Sanger
  9. 13. Wetlands defined <ul><li>Wetlands are defined by three characteristics: hydrology, soils, and vegetation. </li></ul>Ecosystem defined
  10. 14. Wetland Functions <ul><li>Fish and wildlife habitat </li></ul><ul><li>Water quality improvement </li></ul><ul><li>Flood storage </li></ul><ul><li>Shoreline protection </li></ul><ul><li>Recreation/aesthetics </li></ul>1995 San Jose Floods Chinook Salmon
  11. 15. Morphological Adaptations
  12. 16. Physiological Adaptations <ul><li>Excreting salt crystals (cordgrass) </li></ul><ul><li>Retaining water (pickleweed) </li></ul>
  13. 17. Endangered Species (in San Francisco Bay) <ul><li>California Clapper Rail </li></ul><ul><li>Salt marsh harvest mouse </li></ul>
  14. 18. San Francisco Bay: Mixed Semi-Diurnal Tides When there are two high tides each day but with different heights (and two low tides also of different heights).
  15. 19. Tidal Prism: The volume of water that flows into and out of an estuary in one tidal cycle.
  16. 20. Subsidence <ul><li>Tidal marshes are in a dynamic equilibrium, and rely on constant sediment input. </li></ul><ul><li>Salt ponds have retained the historic channel network, but are now at a lower elevation. </li></ul><ul><li>Restoration actions need to include promoting sediment accumulation </li></ul>Source: www.lacoast.gov
  17. 21. Why Restore the South Bay? Docent-led Interpretive Tour Least Sandpipers 1983 Alviso Floods
  18. 22. Regional Planning Efforts
  19. 24. Salt Pond Acquisition © Mark Rauzon © Cargill Salt
  20. 25. Cost of Acquisition <ul><li>16,500 total acres </li></ul><ul><ul><li>15,100 in South Bay </li></ul></ul><ul><ul><li>1,400 along Napa River </li></ul></ul><ul><li>$100 million cost </li></ul><ul><ul><li>$72M - State of California </li></ul></ul><ul><ul><li>$8M - United States government </li></ul></ul><ul><ul><li>$20M - Packard, Goldman, Hewlett, and Moore foundations </li></ul></ul>May 29, 2003 Acquisition Ceremony
  21. 27. Ecological Trade-offs <ul><li>Tidal Marsh species vs. Salt Pond species </li></ul>
  22. 29. Wetland Restoration 101 <ul><li>Restore tidal action by breaching levees at historic slough locations </li></ul><ul><li>Encourage sedimentation in subsided marshes </li></ul><ul><li>Maximize habitat values for target species </li></ul><ul><ul><li>Upland transition zones for salt marsh harvest mouse </li></ul></ul><ul><ul><li>Sinuous channels for California clapper rail </li></ul></ul><ul><li>Active revegetation and invasive species removal </li></ul>
  23. 30. Narrow strip marshes do not allow for complex channel development Abrupt levee transitions do not provide high tide refugia Restored Marshes should target specific habitat features
  24. 35. <ul><li>H.T. Harvey & Associates </li></ul><ul><ul><li>Aerial photos by Karen Verpeet </li></ul></ul><ul><li>Philip Williams & Associates </li></ul><ul><li>Don Edwards San Francisco Bay National Wildlife Refuge </li></ul><ul><li>California State Coastal Conservancy </li></ul><ul><li>EDAW </li></ul><ul><li>SFEI </li></ul>Acknowledgements
  25. 36. <ul><li>Preliminary Design Concept </li></ul><ul><li>Combine scientific, cultural and recreational components </li></ul><ul><li>Refuge Branding? </li></ul>

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