This week's high tides swamped the parking lots outside Sausalito's houseboat docks, so residents had to wade through water to reach their floating homes, CBS News Bay Area reported. ABC7 News aerial footage showed a lot near the houseboats completely underwater, with a flower delivery van stalled in the flooding.

"I've been here 32 years and I've never seen a tide come up this high, ever," resident Court Mast told CBS. He said one high tide was predicted at 6.6 feet but behaved like 8.1, "a foot and a half more water than we are used to seeing." Neighbors have been following a smartphone app one resident built to track conditions in the community.

The worries: power and pilings

Mast told CBS the water came close to the community's emergency water system. Another foot or so of rise would reach the power lines feeding each home. "If those start to get inundated with salt water, the whole place will shorten out," he said. Houseboats are held to pilings by collars that slide up and down with the tide. Some pilings are fairly low, and Mast said the fear is a collar slipping off the top and a house floating away. He has added an extra sleeve to his own piling.

Why the tides are so high, and what's next

Meteorologists told CBS that this year's strong El NiƱo is pushing sea levels higher through thermal expansion. ABC7 reported that the Coastal Flood Advisory was extended through Friday, and that Marin County Public Works aims to have about 45,000 sandbags ready in the coming weeks. "We're expecting the first major King Tides the week of Thanksgiving," said assistant public works director Michael Frost. See our earlier coverage of Mill Valley road closures from the same tides.