addressing climate change adaptation in regional transportation plans

• Coastal flooding presents a risk to major transportation infrastructure inthe region including freeways, rail lines, ports, and airports (especially SanFrancisco and Oakland).• “The impacts of climate change are expected to substantially alter the Bayecosystem by inundating or eroding wetlands and transitional habitats,altering species composition, changing freshwater inflow, and impairing waterquality. Changes in salinity from reduced freshwater inflow may adverselyaffect fish, wildlife and other aquatic organisms in intertidal and subtidalhabitats. The highly developed Bay shoreline constrains the ability of tidalmarshes to migrate landward, while the declining sediment supply in theBay reduces the ability of tidal marshes to grow upward as sea level rises”(BCDC, 2011, p. 5).With the large number of local and special purpose governments in the region,addressing the sea level rise problem will require regional collaboration involvingthe California Coastal Commission and San Francisco Bay Conservation andDevelopment Commission. The San Francisco Planning + Urban ResearchAssociation (2012) has recommended the following actions for addressingclimate change:• Barrier(s) or tidal barrage(s) to manage tidal flows in and out of SanFrancisco Bay (at the Golden Gate or in smaller, strategic parts of the bay)• Coastal armoring with linear protection, such as levees and seawalls, to fixthe shoreline in its current place• Elevated development in which the height of land or existing development israised and protected with coastal armoring• Floating development on the surface of the water, or development thatmay be floated occasionally during a flood, making it largely invulnerable tochanging tides• Floodable development designed to withstand flooding or to retainstormwater• Living shorelines with wetlands that absorb floods, slow erosion, and providehabitat• Managed retreat that safely removes settlement from encroaching shorelines,allowing the water to advance unimpeded, and bans new development inareas likely to be inundatedAlameda and San Mateo counties could see significant increases in the numberof United States Environmental Protection Agency (U.S. EPA)-regulated sitesat risk for sea level rise, including Superfund sites, hazardous waste generators,facilities required to report emissions for the Toxics Release Inventory, facilitiesregulated under the National Pollutant Discharge Elimination System (NPDES),major dischargers of air pollutants with Title V permits, and brownfield properties(CCCC, 2009).PAGE 33APG: UNDERSTANDING REGIONAL CHARACTERISTICS