Caltrans Punts Sea Level Rise Planning for 101 Corridor Project

Humboldt Baykeeper logo In August, the California Coastal Commission met in Eureka to consider the long-anticipated permit for Caltrans’ “Eureka-Arcata Highway 101 Corridor Safety Improvement Project,” which features an interchange at Indianola Cutoff, a left-turn signal at Airport Drive, and closure of all other medians. The plan—in progress for more than fifteen years—is intended to eliminate uncontrolled left turns to make the road safer, but the speed limit will likely increase to 65 mph, making the road less safe. In addition, increased traffic will undoubtedly affect alternate routes through Bayside and Manila, both during and after construction.

Bay Trail and billboard removal 

In 2013, the Coastal Commission directed Caltrans to build the Bay Trail, remove the billboards along Humboldt Bay, and plan for sea level rise before coming back for a Coastal Development Permit for this project. Thanks to the Coastal Commission’s 2013 decision, the Bay Trail will be completed in 2021, and eight billboards were removed as a result of an agreement that Caltrans made to allow Outfront Media to build a higher density of billboards in Los Angeles.  Seven other billboards were permanently removed by various means: two were cut down in the dark of night, one fell over in a storm, one was plowed down by a car accident, and three were removed from the railroad right-of-way after years of public pressure.

Unfortunately, neither Caltrans or the Coastal Commission had the wherewithal to insist on removal of the four remaining billboards near Indianola Cutoff, including three billboards in the bay mudflats. We will continue to press for removal of these remaining billboards, which were built on public trust tidelands before permitting, zoning, and the Coastal Act
outlawed them years ago.

Preparing for sea level rise punted again

A little over a week before the August hearing, we learned that the Caltrans plan for sea level rise was to kick the can down the road again – this time, until 2030. The Coastal Commission voted to move that deadline up to 2025, or sooner if the highway is closed due to flooding four times within a 12-month period.

According to local experts, significant portions of the highway corridor will be flooded on a monthly basis with 1.6 feet of sea level rise, which is projected to occur by 2040. It is also located in the 100-year flood zone, a tsunami hazard area, and an area of potential
soil liquefaction.

Major oversight results in $20 million cost increase

And in early September, after the project was approved, it was revealed that Caltrans had designed the interchange without taking into account that it will be built entirely on wetland fill. At a meeting of the Humboldt County Association of Governments (the local agency responsible for planning the funding for state highway and local road improvements), Caltrans announced a $20 million increase in project cost due to this major oversight. The project is now expected to take even longer as well as cost more due to the need for compaction and time for the soil to settle before
building the interchange.

‘Ground zero’ for sea level rise

The Humboldt Bay area has the highest rate of sea level rise on the West Coast. Here, relative sea level is rising twice as fast as in the rest of California due to tectonic subsidence (meaning that the ground beneath us is sinking at the same rate that the sea is rising). A decade of work has been done by Aldaron Laird and others to assess the region’s vulnerability to rising sea levels.

Of all the public infrastructure that will be increasingly at risk from storm damage and flooding, U.S. Highway 101 is arguably the most vulnerable—particularly the section of highway just north of Eureka. Some say that sea level rise is like a slow-motion flood, arguing that we don’t need to plan for it now. But if we fail to adapt to what we now know is coming, regardless of whether we can slow down climate change, catastrophic damage could happen overnight. How are we going to use this knowledge to keep people, public infrastructure, and ecosystems out of harm’s way?

Biologists, ecologists, and environmental advocates worry that many plants, animals, pollinating insects, and other species will be unable to adapt to the changing climate and oceans. But it is becoming increasingly clear that under the current paradigms, society is unlikely to be able to adapt in time to prevent disasters of our own making, even though
we know we must.

Flyer for Humboldt Baykeeper anniversary party.