Sea Level Rise

The Humboldt Bay area is experiencing the fastest rate of relative sea level rise on the West Coast. That's because tectonic activity is causing the ground beneath the bay to sink at the same rate that the ocean is rising. According to the California Ocean Protection Council's 2024 Science & Policy Update, sea level in the Humboldt Bay area is expected to rise approximately 1.5-2 feet above 2000 levels by 2060 and 3.9-5.5 feet by 2100.

The primary impacts from sea level rise are increases in flooding, erosion, and rising groundwater. Sea level rise will expand areas vulnerable to flooding during major storms, as well as in the rare but catastrophic event of a major tsunami. The term 100-year flood is used as a standard for planning, insurance, and environmental analysis. But these extreme storms are happening with increasing frequency, in part due to rising seas. Sea level rise will cause more frequent—and more damaging—floods to those already at risk and will increase the size of the coastal floodplain, placing new areas at risk to flooding.

To view sea level rise scenarios for the Humboldt Bay area, visit NOAA's 2022 Sea Level Rise Viewer and go to the local scenario for the North Spit.

Interactive Map of King Tide Photos

The California Coastal Commission's King Tide Photo Project features photos from the Humboldt Bay area and across the state. Anyone can upload photos online or via a smartphone app. Click HERE to upload yours.

Wondering about good spots to view the King Tides around Humboldt Bay? Visit our Humboldt Bay King Tide Photo Project.

Left: Erosion along New Navy Base Road in Samoa during the December 23-24, 2022 King Tides. Photo by Jen Kalt.

King Tides are back sans storms

Solar-lunar alignment create big waves, but flooding risk minimal

1/20/15

The winter’s highest tides are predicted for this week, but without the storms that hit Humboldt County in late December, flood risk is minimal, according to the National Weather Service.

National Weather Service meteorologist Matthew Kidwell said the tide, which is considered a King Tide because of the alignment of the sun and the moon, peaked at 8.4 feet Monday morning and will probably be a little higher today and Wednesday.

“It’s actually going to be the highest (today), probably around 8.4 feet again,” Kidwell said. “But it usually has to get up to around 8.8 feet before we start seeing flooding.”

King tides hit coast, cause minor flooding

12/23/14

The highest and lowest tides of 2014 known — as the “king tides” — hit California’s coast on Monday, with this year’s event getting a leg up from the recent offshore winds, according to National Weather Service meteorologist Kathleen Lewis.

“The tides have been predicted to be just around 8 feet, but they’ve been higher,” she said. “One reason is because of the southerly winds offshore, and that helps create a surge that pushed against the coast. We have been seeing southerly winds for quite a while. That has been causing the difference in the tide to be higher than projected levels.”

The old man and the rising sea

On one of the most vulnerable islands in America, a longtime caretaker makes peace with climate change.

12/2/14

At the south end of Assateague Island, on a storm-shaped hook called Tom’s Cove, Ishmael Ennis likes to pace the beach. Autumn Sundays are the best time of year, he said, when the dawn chill clears out the crowds. In those solitary moments, the sands seem vast enough to drown any human concerns.

“No, that’s getting too romantic,” he said, suddenly self-conscious. Ennis, 59, grew up near a crabbing town on the Chesapeake Bay. He’s tall, hay-haired, and speaks with a waterman’s drawl. “I don’t feel nothing too special,” he said. “Just sometimes you’ve got to get away from all the normal stuff. The island offers that.”

Not for long, perhaps.

How will we plan for Sea Level Rise? Mon. Nov. 17, 2014

Why is sea level rising twice as fast here as it is along the rest of the Pacific coast? Which areas around Humboldt Bay are most likely to be under water in the future? How will sea level rise affect the agricultural lands on former bay tidelands? How will Caltrans keep Highway 101 above water? What will happen in low-lying areas of Arcata and Eureka?

The Humboldt Bay Sea Level Rise Adaptation Planning Project will provide an update for the public at the Humboldt Bay Aquatic Center, 921 Waterfront Drive, Eureka.

Rising seas: 'Living on borrowed time'

Relative sea level rise on Humboldt Bay highest in state

 11/9/14

Climate change has been called a “long emergency,” with impacts ranging from the current extreme drought in California to globe-spanning disruptions of weather patterns and ecosystems predicted for the coming decades. Here in Humboldt County, one of the many predicted impacts is sea level rise, which experts say could threaten underground utilities and U.S. Highway 101. Here’s a look at what the county is doing to adapt.