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 is sinking at the same rate the ocean is rising. According to the California Ocean Protection Council's 2018 projections, sea level in the Humboldt Bay area is expected to rise above 2000 sea level as much as 1 foot by 2030, 2 feet by 2050, and 3 feet by 2060. In late 2021, scientists reported that Antarctica's Thwaites Glacier is likely to collapse within 5 to 10 years, which could result in an additional 2 to 10.8 feet in sea level rise. The primary impacts from sea level rise are increases in flooding and erosion. Sea level rise will expand the area 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.

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

A Slow Motion Flood: Rapid Sea Level Change on the North Coast

2/15/12

Rapid sea level rise in the next 100 years could affect more than coastal residents may think.

The rise could change the environment of the Arcata Marsh, create prime salmon habitat or affect property values, said local scientist Michael Furniss.

Rough Waters for Sea Level Rise Planning

7/29/11

What do Bay Area airports and some big Silicon Valley companies have in common? They sit right on the edge of San Francisco Bay, where sea level rise is expected to have a big impact by the end of the century.

That may seem far in the future, but state agencies are preparing for climate change now by writing new rules for construction along the bay’s shoreline. As you can imagine, developers and environmentalists aren’t exactly seeing eye to eye.

King Tide Photo Initiative: Dec. 23, 2022 & Jan 21, 2023

King Tides are coming on Friday, Dec. 23 & Saturday, Jan. 21. To get involved, all you need is a camera or a smartphone. Submit your photos to This email address is being protected from spambots. You need JavaScript enabled to view it..

Photo: Waves crash over the South I Street parking lot and boat ramp at the Arcata Marsh, Jan. 3, 2022. Photo by Kristen Orth-Gardinier.

King Tide Photo Initiative: January 20-21, 2023

The highest tides of this winter (known as King Tides) are predicted on Friday & Saturday, January 20-21.

These tides may be much higher than predicted due to the southerly winds and Eckman Transport, which piles water up along our coast. Please USE EXTREME CAUTION when viewing the King Tides! And remember to wear bright colors so drivers can see you.

To get involved, all you need is a camera or a smartphone. Submit your photos to This email address is being protected from spambots. You need JavaScript enabled to view it. or upload them to the California King Tide Photo Project.

Photo: Erosion along New Navy Base Road in Samoa dislodged a PG&E vault during the December 23-24 King Tides.

2021-22 King Tides Photos

In early January, extreme high tides (known as King Tides) coincided with a major storm, resulting in many dramatic images submitted by volunteers that reveal the vulnerability of roads, bridges, and other low-lying infrastructure around Humboldt Bay.

To see some of the best submitted photos from the 2021-22 King Tides, check out our King Tides Photo Album 2021.

Photo: King Tide waves near the old railroad tracks across from the bay entrance (south of Elk River). Robin Gray-Stewart, 12-4-21.