Humboldt’s location at the end of the Cascadia Subduction Zone makes the area more vulnerable to sea level rise than any other location on the California coast. Due to its position in a very active tectonic area and the specific activity of the surrounding plates, the Humboldt County region is steadily sinking, or subsiding.
The Humboldt Bay Vertical Reference System Working Group is a research group focused on identifying geology’s role in Humboldt Bay sea level rise. In a 2017 report, they found that land subsidence contributes to sea level rise 2 to 3 times more in Humboldt County than anywhere else in California. Of the 18 inch rise in sea levels that has occurred locally in the past century, an estimated 50% is due to tectonic subsidence.
“The ocean isn’t rising any faster off of our coast than it is down in San Francisco, but we have subsidence that the rest of California doesn’t have,” said environmental planning consultant Aldaron Laird.
Laird has been an essential part of local sea level rise risk assessment and adaptation planning over the last decade, consulting with Humboldt County and various local districts.
Humboldt County has commissioned many reports which assess the risk that sea level rise poses to infrastructure and communities. These contextualize what different levels of sea level rise will mean, and suggest possible adaptation measures. However, the reports do not implement the adaptation measures.
The most recent grant-funded project to tackle this issue concluded in 2019, yet none of the recommendations from that, or any other report, have been implemented.
An area that the reports do not touch on is the potential for industrial contamination in the bay as sea level rise reaches new areas.
In her career as an environmental advocate, Jennifer Kalt has observed the local government’s lackluster reaction to the threat of sea level rise for years.
“What I have seen as a repeating theme is a lot of local jurisdictions getting grant money to develop plans and then there isn’t a plan,” said Kalt. “It’s a little depressing to see so much planning lead to nothing.”
Michael Richardson is a supervising planner of long range planning in the Humboldt County Planning and Building Department, which is responsible for sea level rise adaptation planning. He said that the county would like to decide on terms of collaboration with other local jurisdictions before they plan to implement any sea level rise adaptation measures. Simply put, they don’t have immediate plans to do anything specific.
“There would be a different process to go forward with getting the cities and the county on the same page and whatever agreements need to be made,” said Richardson. “What that plan looks like is what we’re still figuring out.”
Kalt doesn’t think that the pace at which the government is moving on this issue will make a difference in time. In addition to protecting residential areas, she said that their focus should be on relocating key infrastructure.
“I’m concerned that a lot of the agencies that need to address these problems, there’s not a lot of political will to do what needs to be done,” said Kalt.