PLANNING FOR RISING SEA LEVELS NBWA November 5, 2010

Preliminary Study Vulnerability Vulnerability Adaptation Strategies Adaptation Strategies Next Steps Next Steps

HASPA Hayward Area Shoreline Planning Agency

Potential inundation Light Blue – 16 in Light Blue – 16 in Dark Blue – 55 in Dark Blue – 55 in Source: USGS, BCDC

Functions Urban Urban Habitat Habitat Storm drainage Storm drainage Land fill Land fill Sewage treatment Sewage treatment Utility corridors Utility corridors Trails Trails Oliver Brothers Property Hayward Marsh Triangle Marsh Alkali Flat Cogswell Marsh Oro Loma Marsh

Storm drainage Designed for a certain bay elevation Designed for a certain bay elevation Lack of drainage as MLLW rises Lack of drainage as MLLW rises Structures fixed relative to tide frame Structures fixed relative to tide frame Upstream impacts will increase Upstream impacts will increase Exposure increases with time Exposure increases with time Adaptation may require pumping Adaptation may require pumping Opportunity to consolidate Opportunity to consolidate

Functions Urban Urban Habitat Habitat Storm drainage Storm drainage Land fill Land fill Wastewater Wastewater Utility corridors Utility corridors Trails Trails Oro Loma wastewater treatment plant Solar drying ponds KOFY Alameda County West Winton Ave City of Hayward wastewater treatment plant

Functions Urban Urban Habitat Habitat Storm drainage Storm drainage Land fill Land fill Sewage treatment Sewage treatment Utility corridors Utility corridors Trails Trails PGE EBDA line Railroad Cable HP Gas Bay trail

Frank’s Dump West - New Year’s Eve ft tides; 40mph westerly windsPhoto: Mark Taylor Inundation

Erosion

Groundwater Elevation Armored levee Levee slope increases as mudflat lowers and levee raised

Hold the Line

Armored levee Levee slope increases as mudflat lowers and levee raised

Realign Rapid landward movement increases as sea level rises

Opportunities - Sediment Trapped in channels in watershed Trapped in channels in watershed Trapped in marinas further alongshore Trapped in marinas further alongshore In the past, sources were more diffuse In the past, sources were more diffuse

Opportunities - Freshwater Large amount of freshwater passes through area Large amount of freshwater passes through area Opportunity to reconfigure EBDA line Opportunity to reconfigure EBDA line In the past, sources were more diffuse In the past, sources were more diffuse

Opportunities – Brackish Marsh Historic element of the Bay Historic element of the Bay Greater biomass, wave attenuation and sediment trapping Greater biomass, wave attenuation and sediment trapping Grow the marshes upwards Grow the marshes upwards Steepen the existing natural shoreline Steepen the existing natural shoreline Adaptively respond to changes in sea level Adaptively respond to changes in sea level

Gradual Steepening Rapid landward movement increases as sea level rises MudflatTidal MarshBrackish Marsh Freshwater Swale Impermeable Berm or Wall Seepage Berm Bay Cut off wall

Gradual Steepening Rapid landward movement increases as sea level rises MudflatTidal MarshBrackish Marsh Freshwater Swale Treated Wastewater and Stormwater Seepage Overflow Wave Attenuation

Gradual Steepening Rapid landward movement increases as sea level rises MudflatTidal MarshBrackish Marsh Freshwater Swale

Nearshore (detached) barrier beach Fringing (attached) barrier beach

Diffused Armoring

Next Steps Master Plan Master Plan Vulnerability Assessment Vulnerability Assessment Infrastructure Infrastructure Ecology Ecology Property Property Adaptation Strategy Adaptation Strategy Interim Management Interim Management

San Pedro Road, China Camp - January 2010 spring tide Photo: Peter Baye Preview of the late 21st century?