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Humboldt Bay is retaking the land as the sea level rises

Fortification of dikes needed to protect infrastructure like Highway 101

Humboldt Bay is reclaiming its former territory, and there’s nothing anyone can do to stop it.

Between 1890 and 1910, almost 90% of Humboldt Bay’s salt marshes, about 8,100 acres, were “diked and drained for agricultural uses or walled off from tidal inundation with the construction of the Northwest Pacific Railroad,” according to the “Humboldt Bay Shoreline Inventory, Mapping and Sea Level Rise Vulnerability Assessment” completed in 2013 by local sea level rise expert Aldaron Laird. Now only 4% of the land is salt marsh.

After keeping the sea at bay for over a hundred years, the earthen dikes are beginning to fail, both because they haven’t been maintained and because they aren’t tall enough to hold back the rising tides brought on by rising sea levels.

The dikes, which are on average 10 feet tall, are finding it increasingly challenging to hold back tides that are ranging from 7.8 to 9.5 feet in height. When a 9.5-foot extremely high tide and storm surge joined forces to damage the dikes in the area in 2006, the governor had to declare a state of emergency, but those types of high tides are expected to be the monthly norm by 2050.

“Sea level rise is an effect of climate change, specifically from the warming of the atmosphere and oceans,” stated more recent 2018 research from Laird entitled “Diked Shoreline Sea Level Rise Adaptation Feasibility Study.” “Going forward, melting ice from areas like Greenland and Antarctica have the potential to greatly accelerate the rate and elevations of sea level rise, particularly after 2050.”

‘Floodier future’ expected in Humboldt Bay, other coastal regions

Local expert Aldaron Laird said, ‘We need to be hustling and get this stuff done now’

The future for coastal regions like Humboldt County is expected to get “floodier.”

A report released Wednesday by the National Oceanographic and Atmospheric Administration predicts that sunny day flooding, also known as tidal flooding, will continue to increase. This year, Humboldt Bay is expected to experience six to 12 days of sunny day flooding after experiencing 12 such days in 2018.

Aldaron Laird, an environmental consultant with Trinity Associates, has been working on the issue of sea level rise in Humboldt Bay for over a decade and said the local jurisdictions are making steady progress to address the issue. They first did an inventory of the areas that would be most susceptible to sea level rise, which include King Salmon and Fields Landing, and are now shifting gears toward preventing the damage it will cause.

Caltrans will be going before the California Coastal Commission in August to go over the impact of sea level rise on the U.S. Highway 101 corridor.

“Over the next five to 10 years,” Laird said, “that’s when all this stuff will get worked out.” But Laird said that timeline is “cutting it close.”

While the utility owners and Caltrans rely on the dikes to protect Highway 101 and the utility lines, Laird said many of the dikes are eroding and lie in various states of disrepair. The dikes are mostly 10 feet tall and the tides have risen to about nine feet tall, so Laird said just one foot of sea level rise will lead to thousands of acres being flooded every day.

“We could have two feet of sea level rise by 2030 or 2050,” Laird said.

Humboldt Baykeeper gets $40K to test more North Coast fish for mercury

The California Environmental Protection Agency awarded Humboldt Baykeeper, a program of the environmental conservation nonprofit Northcoast Environmental Center, $40,365 on June 26 to test Pacific lamprey, lingcod, rockfish and other fish species for mercury.

“The idea here is to get some more local information so people can base what they’re feeding themselves and their children in particular on local data instead of general data from other parts of the state,” said Jennifer Kalt, director of Humboldt Baykeeper.

A previous grant from the state EPA allowed Humboldt Baykeeper to assess the mercury content in coastal fish and shellfish and put out guidelines, which are available in English, Spanish and Hmong, regarding which ones are safest to eat.

“From that study, we had a lot of good news and bad news,” Kalt said. “Chinook Salmon are very low in mercury, so you can eat those up to 28 times per month. That’s good for tribal members because that amount is consistent with the amounts of fish they might eat.”

Clam Beach waters second worst in state

Heal the Bay released its 29th annual beach report card its week, and for the sixth straight year in a row, Clam Beach has received an F for its recreational water quality.

This year Clam Beach was ranked second worst in the state, right after San Clemente Pier in Orange County. Four of the other five beaches in Humboldt County where water quality is monitored by the county received passing grades — Mad River Beach got an A+, Trinidad State Beach received an A, and Moonstone and Luffenholtz beaches received grades of C.

“We all know Clam Beach has been on list for the past six years and it fluctuates where it is on the list,” said Amanda Ruddy, supervising environmental health specialist at the county’s Department of Health and Human Services. “I think it’s important to note last year, we had Luffenholtz on that list and it’s not on the list this year.”

The water quality at beaches across the state dipped during the past year, primarily because of increased rainfall that led to more runoff being carried into the seas through the storm drain systems, according to the beach report card.

Trinidad backs water study as Rancheria hotel project looms

Mayor: 'We cannot extract water to the point of it running dry'

The Trinidad City Council on Wednesday afternoon unanimously approved a study of the city’s water needs, an effort the council framed as necessary preparation for the general future but which most in the public interpreted as a precautionary step ahead of a major hotel development that could rely on the city’s water supply.

The study would include five separate tasks, including an assessment of the city’s current water source, the Luffenholtz Creek; a search for alternative sources of water supply; and developing new city policies to address potential draught.

“It’s very, very important we understand the timeline of this going forward,” said Richard Johnson, a member of the citizen’s group Humboldt Alliance for Responsible Planning, a functional watchdog of the hotel in its early planning.

“My concern is we will put the cart before the horse … that we won’t have the facts and data and public review ready in time for when a decision (on the hotel) needs to be made,” he said.

But Trinidad Mayor Steve Ladwig and other council members emphasized that “with or without” the hotel, studying the Luffenholtz Creek’s effectiveness as a water source is crucial for a distant future with an uncertain environment.

“We cannot extract water to the point of it running dry,” Ladwig said. “During low flows, the city simply cannot get to a point where we can’t expect water.”