HUMBOLDT COUNTY — 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.
“The future is already here, a floodier future,” said William Sweet, a NOAA oceanographer and lead author of the study.
The report predicted that annual flood records will be broken again next year and for years and decades to come from sea level rise.
“Flooding that decades ago usually happened only during a powerful or localized storm can now happen when a steady breeze or a change in coastal current overlaps with a high tide,” it read.
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.
Arcata is currently doing work on its wastewater treatment facility, which is located in Humboldt Bay, to ensure it doesn’t get damaged by sea level rise, Laird said, and Eureka needs to do the same with its facility, which is located along the bay.
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.”
The NOAA says the level of sunny day flooding in the U.S. has doubled since 2000. Nationwide, the agency predicted, average sunny day flooding could reach seven to 15 days a year by 2030, and 25 to 75 days a year by 2050.
“We cannot wait to act,” said Nicole LeBoeuf, acting director of NOAA’s Ocean Service. “This issue gets more urgent and complicated with every passing day.”
Laird echoed that sentiment locally. About one-third of the bay was diked off more than 100 years ago, Laird said. That led to the development of about 270 parcels of agricultural land along the dike shoreline, which are mostly owned by individual property owners, and the construction of the Highway 101 corridor, where utility lines are also located.
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.
That doesn’t leave much time to make much-needed infrastructure improvements. Rebuilding a corridor like Highway 101 takes a lot of time, Laird said, because you have to relocate all the utility lines.
The area isn’t going to be inundated by the end of the century; it is likely to be within the next 30 years. And the flooding of Highway 101 could happen as early as this winter.
“We don’t really have a lot of time,” Laird said. “We need to be hustling and get this stuff done now.”
The Associated Press contributed to this report. Sonia Waraich can be reached at 707-441-0506.
