On January 9, 2023, I met with Aldaron Laird for a close to two-hour meeting about his views on the sea level rise situation here on the North Coast. (Mostly he talked and I listened.) At the Planning Commission Meeting at the following evening, I gave a synopsis of what I learned from Aldaron.
Aldaron Laird is highly regarded as an expert on the effects of sea level rise on coastal California. He was on the Arcata Planning Commission for ten years, from 1996 to 2006, and was very involved in the production of the General Plan 2020 (adopted in October 2000). In 2013, under a grant from the State Coastal Conservancy, Aldaron completed a 102-mile survey of the Humboldt Bay shoreline — almost entirely on foot or by kayak — to assess areas most vulnerable to sea level rise.
Perhaps Aldaron and fellow sea level rise experts Jeff Anderson and Brad Finney could do a presentation to the City Council and the Planning Commission on this issue.
Here is the video of that six-minute synopsis. The transcription is below.
Thank you, Chair.
I met with Aldaron Laird yesterday for about an hour and a half or almost two hours. Aldaron, as you know, is recognized as one of the leading experts on sea level rise in the State. Mostly I listened and took notes. He’s a scientist. I’m not a scientist. I’m more concerned about how it impacts development in Arcata. Of course, sea level rise is an issue globally. So these are some of the notes.
He may be available to speak before the City Council and the Planning Commission. We’ll talk about that another time.
So. Commissioner Mayer has brought up the notion of emerging groundwater. Aldaron pointed out that while sea level rise is obviously of largest concern, there are other issues. Emerging groundwater is one, and the breaching of the existing dikes. And then of course, the improvements required to the wastewater treatment plant and the consideration of moving the plant.
He pointed out that NOAA — National Oceanic and Atmospheric Administration — regards flooding from a king tide that happens two or three times a year to be a nuisance. When it happens more than 4 or more times a year it’s considered a chronic condition. For those of us who are here in 2005: There was a large storm on New Year’s Eve, as well as high winds and a king tide. It registered the highest level of 9.6 feet [the highest level ever recorded]. Aldaron walked at the Arcata Marsh, he found 18 places where the dikes were breached. The average king tide now is 8.8 feet. That was 9.6 feet. So we’re really talking about [less than] one foot of sea level rise to make a difference. This is not something way in the future. We’re not talking about three feet or six feet or that kind of thing.
King Salmon is considered to be flooded in less than 20 years. That’s lower than we are, of course. But it is his opinion that just one foot of sea level rise, which could happen in 20 years [here], will breach the dikes. When that happens, more area gets flooded, there’s a groundwater problem. It doesn’t necessarily apply to sea level rise for the buildings. But it is a problem.
The for those of you who know, the dikes date from about 1870, when the whole area was salt marsh. If you look at Old Arcata, out towards Three Corners — all that from there to the bay was salt marsh. Looking at the salt marsh maps that Aldaron provided, it pretty neatly coincides with the Gateway district. That’s about 20 feet elevation above current sea level.
As he put it, no one can question **IF** this is going to happen. It’s just a question of when. And so when we’re looking at construction, we’re looking at the useful life of the buildings, it’s likely that this is going to happen within the useful life of new buildings.
There have been five studies [major studies, over 30 years] on how sea level rises, the prediction of sea level rise, that have been done. Each of the five has come up with a different prediction that is quicker or sooner than the previous one. And it’s possible that’s going to continue. So as time goes on, it may be a bigger problem than we thought.
I asked Aldaron for his opinion on how the Coastal Commission might view some of these issues. He can’t of course say what the Coastal Commission is going to do. But he doesn’t believe that the Coastal Commission is going to be very amenable to building housing in this area. They look at 100 year expected sea level rise. And that’s pretty much the whole Gateway area. As part of their assessment, they may require that lower levels of the buildings be not for residents, which could fit in with the desire to have commercial in the lower levels. They may require breakaway walls on the buildings. Again, we don’t know. And, as I understand it, I think David will confirm, they don’t offer suggestions, we apply the project to them and then they work from there.
I read through the February 2022 draft of the Local Coastal Element that is going to be worked on this year. It’s my view that if the words there are followed as they are written, then no development can occur below Eighth Street [that is: in the Local Coastal Zone, which comes up to 8th Street]. That’s just my opinion, from reading the language, reading the qualifications that are expressed in the Local Coastal Element draft. This would include the AmeriGas site, the old St. Vinny’s building, where Tomas used to be and Open Door Clinic is now, the Greenway building, the trailer park, Wing Inflatables, the entire industrial area along Samoa, and more.
Commissioner Mayer had suggested at one point creating district boundaries that coincide with the Coastal Zone. This would not be difficult. Currently the Gateway Corridor just it goes from Samoa to a little above 11th Street. That can be divided into a Lower Corridor — from Samoa to Eighth — and an Upper Corridor, from Eighth to 11th Street.
That’s the report. As I said, he and perhaps Jeff Anderson and Brad Finney could do a presentation to the City Council or a joint session on this.