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.”
