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.

NEW! Now you check out our interactive map of two sea level rise scenarios for the Humboldt Bay Area! Featured are scenarios showing 1- and 2-meters above Year 2000 water levels. For many years, these have been static maps with no simple way for the public to examine points of interest. Now, people wondering if their neighborhood is at risk can zoom in on locations and see street names, etc.

King Tide Photo Initiative: Nov. 26 & 27, 2019

On Tues. and Wed. (Nov. 26-27), the first “King Tides” of this winter will coincide with a winter storm, which could lead to coastal flooding. Be very cautious of rising water, eroding shoreline, flooded roadways, and high winds.

Baykeeper volunteers have been documenting King Tides since 2011. To get involved, 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..

Photo: Arcata's Wastewater Treatment Facility, 12-14-16. Photo by Rich Ridenhour.

King Tide Photo Initiative, 2017-18

The highest tides this winter - known as King Tides - will occur on Dec. 4-5 and Jan. 1-2. 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.

Left: View from the Del Norte Street Pier in Eureka.

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.