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.

Sea Level Rise Vulnerability Assessment of Contaminated Sites

How we will prepare for rising sea levels is just beginning to take shape here in the Humboldt Bay region. Humboldt Baykeeper has assessed sea level rise vulnerability for contaminated sites near Humboldt Bay. More than 300 contaminated sites are within 10 meters of current sea level, including more than 40 that are below 2 meters – the amount sea level is projected to rise by the year 2100.

Humboldt Bay Sea Level Rise Adaptation Planning Project

Phase I: Shoreline Inventory, Mapping, and Vulnerability Assessment

A report to the State Coastal Conservancy by Aldaron Laird, Brian Powell, and Jeff Anderson.

Click below to download the report:

Humboldt Bay Shoreline Inventory, Mapping and SLR Vulnerability Assessment (PDF, 45 MB)

Addendum: Dike and Railroad Shoreline Vulnerability Rating

Biggest tides of the year set to hit California

12/12/12

If you head down the beach this week, or wander along the edges of San Francisco Bay, you may just be witnessing California's future.

The ocean is getting closer.

San Francisco: a Test Case for Coping with Rising Seas

2/1/13

Parts of New York and New Jersey are still reeling from Superstorm Sandy, an event that brought climate change and the threat of sea-level rise front-and-center. It's a looming problem for all coastal cities, and one that San Francisco has been pondering since long before Sandy struck. Along San Francisco’s western shore, the Ocean Beach Master Plan is a kind of test case for sea-rise planning. It calls for big changes, including a strategy known as managed retreat.

East coast flooding: Wake up call for Humboldt County

11/28/12

This year America watched sea levels rise and the ocean flood cities across the east coast in late October. Humboldt County faces a similar threat.

Mid-November to early December is when flood risk is the highest. A storm during the high tides of that time can overtake the dikes around Humboldt Bay, flood the area and cost the county millions of dollars to recover.