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.

King Tides Tour, December 14, 2016 in Arcata

At 11:30 am on Wed. Dec. 14, Humboldt Baykeeper and Sea Level Rise Planner Aldaron Laird will host a tour during the highest tide of 2016-17. The tide is predicted to reach 8.6' at noon, although it could be up to a foot higher in stormy conditions.

We'll meet at the Arcata Wastewater Treatment Facility on South G Street. From there, we'll walk to the King Tides Observation Bench, which was donated to the City by Aldaron & Christy Laird in January.

Humboldt Bay King Tide Photo Initiative 2016-17

The highest tides this winter - known as King Tides - will occur on Oct. 17, Nov. 17, Dec. 13-14, Jan. 11-12.

To help document this year’s King Tide, All you need is a camera or a smartphone. Submit photos to This email address is being protected from spambots. You need JavaScript enabled to view it..

Be very cautious of rising water, eroding shoreline, flooded roadways, and high winds during any extreme high tide events.

Photo by Saroj Gilbert, South I Street in Arcata, 10-28-15.

New Year’s Day King Tide On Liscom Slough

1/2/13

JACKSON RANCH ROAD – Skunky LaRue was nowhere to be found during today’s King Tide along Liscom Slough, but Ted Halstead and Third District Supervisor Mark Lovelace went kayaking there anyway.

Photos by Ted, Mark and Kevin L. Hoover.

Click HERE to see the photo gallery.