Saltwater waves and heavy maritime use
The Embarcadero -- with Muni's F-Market and Wharves streetcar line and several light-rail lines, along with major sewer infrastructure -- is all on backfilled land made usable by the seawall, which runs from Fisherman's Wharf to Pier 50 south of AT&T Park.
Most of the seawall has held up well during a centurylong pounding by saltwater waves and heavy maritime use, though the Port of San Francisco has had to replace crumbling piers and repair the outer wall at Brannan Street and at Pier 43 in recent years.
However, the seawall has never been tested by a major earthquake, and just how well it would perform during a temblor is currently anybody's guess.
The 1906 earthquake hit before much of the seawall was built, and the 1989 Loma Prieta earthquake, with its epicenter far away, was much weaker by comparison.
Parts of the seawall could move as far as 1 foot after a major earthquake, a 1992 study found.
A review of the seawall's ability to withstand an earthquake of up to magnitude-8.0 could begin this winter, pending Port Commission approval. Results from the $425,000 study could be released next summer.
Even if a big earthquake never hits, rising tides could overwhelm the current seawall within the next few decades, said Steven Reel, project manager at the Port's engineering division.