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.

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.

The highest tides of the winter are predicted for Dec. 14 & 15, and we'll be meeting at 1pm near the boat ramp under the Samoa Bridge to cleanup trash and debris left behind as the tide recedes. 
The tides are predicted to peak at the North Spit tide gage at 9:56 a.m. on Saturday, Dec. 14 and at 10:42 a.m. on Sunday, Dec. 15 (check your favorite tide tables or NOAA’s tide predictions for other locations). 

NewNavyBaseRd12 24 22The 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.

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.

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.

More Articles …

  1. King Tides Photo Initiative: Focus on the old railroad, December 4 & 5
  2. King Tide Photo Initiative: January 11 & 12, 2021
  3. Sea Level Rise and King Tides at Eureka Slough
  4. King Tide Photo Initiative: February 8-9, 2020

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