Sea Level Rise

The Humboldt Bay area is experiencing the fastest rate of relative sea level rise on the West Coast. That's because tectonic activity is causing the ground beneath the bay is sinking at the same rate the ocean is rising. According to the California Ocean Protection Council's 2018 projections, sea level in the Humboldt Bay area is expected to rise 1 foot by 2030, 2 feet by 2050, and 3 feet by 2060. In late 2021, scientists reported that Antarctica's Thwaites Glacier is likely to collapse within 5 to 10 years, which could result in an additional 2 to 10.8 feet in sea level rise. The primary impacts from sea level rise are increases in flooding and erosion. Sea level rise will expand the area vulnerable to flooding during major storms, as well as in the rare but catastrophic event of a major tsunami.

The term 100-year flood is used as a standard for planning, insurance, and environmental analysis. People, infrastructure, and property are already located in areas vulnerable to flooding from a 100-year event. Sea level rise will cause more frequent—and more damaging—floods to those already at risk and will increase the size of the coastal floodplain, placing new areas at risk to flooding.

Eureka Plans to Flout Coastal Commission Recommendations on Sea Level Rise

11/18/16

The images are dramatic, showing some of Eureka’s most important areas completely submerged in water. The Bayshore Mall, Costco, Schmidbauer Lumber, even parts of Old Town and Highway 101 would lie beneath the surface of the ocean according to the worst-case-scenario projections for sea level rise and tectonic subsidence by the year 2100 in a new draft report prepared for the City of Eureka.

Humboldt Bay Sea Level Rise Inundation Mapping

Inundation maps were developed by Jeff Anderson of Northern Hydrology & Engineering for the Humboldt Bay Sea Level Rise Vulnerability Assessment Project. The maps show areas vulnerable to existing and future sea levels that are currently protected from inundation due to the natural shoreline, dikes or berms, and railroad or road grades.

King Tides are back sans storms

Solar-lunar alignment create big waves, but flooding risk minimal

1/20/15

The winter’s highest tides are predicted for this week, but without the storms that hit Humboldt County in late December, flood risk is minimal, according to the National Weather Service.

National Weather Service meteorologist Matthew Kidwell said the tide, which is considered a King Tide because of the alignment of the sun and the moon, peaked at 8.4 feet Monday morning and will probably be a little higher today and Wednesday.

“It’s actually going to be the highest (today), probably around 8.4 feet again,” Kidwell said. “But it usually has to get up to around 8.8 feet before we start seeing flooding.”

Obama Moves To Protect Against Flooding From Rising Sea Levels

1/30/15

President Barack Obama issued an executive order on Friday directing federal, state and local agencies to incorporate projections for sea level rise in planning and construction along the coasts.

The new Federal Flood Risk Management Standard requires that all federally funded projects located in floodplains, including buildings and roads, be built to withstand flooding. The requirement, the White House said in a release Friday, would “reduce the risk and cost of future flood disasters” and “help ensure federal projects last as long as intended.”

King tides hit coast, cause minor flooding

12/23/14

The highest and lowest tides of 2014 known — as the “king tides” — hit California’s coast on Monday, with this year’s event getting a leg up from the recent offshore winds, according to National Weather Service meteorologist Kathleen Lewis.

“The tides have been predicted to be just around 8 feet, but they’ve been higher,” she said. “One reason is because of the southerly winds offshore, and that helps create a surge that pushed against the coast. We have been seeing southerly winds for quite a while. That has been causing the difference in the tide to be higher than projected levels.”