Identifying flood risk mitigation strategies to protect San Francisco’s historic piers

The Port selected Arcadis to lead a study evaluating methods that would help the piers withstand sea level rise and flooding. A key consideration: integrating floodproofing measures into pier restoration projects.

With current and projected flood risk data at hand, our resilience specialists set to work on building a comprehensive set of resiliency solutions. Testing each measure against a rigorous set of criteria, the team narrowed down the list to five adaptive flood risk mitigation strategies and two supplemental measures:

• Deploying watertight defenses on the outside of the building to block water
  
  
  
• Retrofitting furnishings with flood resistant materials and allow flooding to occur
  
  
  
• Raising the building’s floor by several feet to be above flood levels
  
  
  
• Installing a permanent raised flood barrier on the outside edge of the pier structure
  
  
  
• Activating a temporary raised flood barrier on the outside edge of the pier structure
  
  
  
• Using floating breakwaters to weaken waves before reaching the pier structure
  
  
  
• Protecting critical building systems (water, wastewater, drainage, gas, electrical, etc.) from harm
  

The proposed resiliency measures are intended to protect the existing structures from flood risk over a substantial portion of this century, reduce the amount of construction needed on the structures, lessen the disruption to the historic waterfront area, and limit the capital costs needed to rehabilitate the underused piers.