King tides paint stark outlook into rising Puget Sound sea levels

This past month has been a rough one for coastal flooding in cities up and down Washington’s coastline as king tides portend the future of rising sea levels’ impacts on the Puget Sound.

According to a study done by the Washington State Department of Ecology (DOE), state experts studying sea level rise are learning from these events to help coastal communities plan for the future.

King Tide season is here with astronomical high waves

King tides are extremely high tides caused by the gravitational pull between the Earth and the moon when the position of the sun and the moon creates the most pull on water.

In December 2022, king tides contributed to coastal flooding after they coincided with a strong, rainy winter storm, low barometric pressure, and prevailing onshore winds.

Sea levels in Seattle have already risen eight inches over the past century, and this trend is expected to continue. Sea level rise will increase the severity of existing coastal hazards, such as shoreline and coastal bluff erosion, storm surge, flooding, and saltwater intrusion.

“The king tides of today will be our everyday high tides in the future,” the press release said.

According to DOE, more than 14,000 homes and buildings, valued at more than $8 billion, will be exposed to coastal flooding by 2050, with an estimated 12 to 34 inches of sea level rise expected.

Working with the Washington Sea Grant, a program with the University of Washington climate conservation publication, along with other partners, the DOE is working to develop a coastal hazard response system to handle these rising sea levels better.

The most recent project put together by the group is the Washington Coastal Resilience Project, a three-year program that aims to develop data projections to give estimates of what Washington’s coastlines will look like for the next 150 years.

These projects have already helped to produce tangible changes in these communities, including Bellingham’s plan to redevelop 237 acres of waterfront property, new floodplain regulations in King County, and Gig Harbor raising its historic net sheds to preserve them better.

So what can you do to prepare for king tides and potential flooding? Here are a few tips from Washington Sea Grant:

• Be safe! Be extra careful when walking on slippery surfaces and be aware of your surroundings.
• Be aware of weather conditions and big waves.
• Always stay a safe distance away from waves.
• Remember to obey safety signage and guard rails.
• Never turn your back on the ocean.