WHAT HAVE BEEN ACCOMPLISHED:

The original seawall was created approximately 100 years ago and it originally functioned as a seawall of the original shoreline. The seawall is listed on the City's Historical Building Study List as a Miscellaneous Historical Resource. When the Southshore development filled in part of San Francisco Bay in the late 1950's, the lagoon system was created and the original seawall was changed from seawall to retaining wall used for drainage retention system for the southern portion of the City. This original seawall was exposed to severe weather, including storms and wave actions over time, resulting in severe cracking and deteriorations in the wall that has compromised the structural integrity.

JMEC has completed preliminary engineering, including the evaluation of the existing seawall for adequacy under service and seismic conditions, and develop embankment strengthening alternatives that do not require doing work to the existing seawall. Four design alternatives have been considered to strengthen more than 300' of embankment along Powell Street, including steel sheet pile wall, secant pile wall, soldier pile wall with concrete lagging and deep soil mixing.  The final design has considered rising sea level per Climate Action Plan under different sea level estimates for 100-year Base Flood Elevation for Alameda (10 ft NAVD88) +3 ft of sea level rise = 13 ft NAVD88. The use of sheet pile wall also mitigate the rising ground water by serving as a cut-off wall.

Schedule:  Design was completed in 2023