Washington map shows where state could be underwater from sea level rise

A new interactive map shows how parts of Washington state could be submerged underwater as sea levels rise due to climate change.

Washington’s extensive coastal regions, which stretch around 157 miles along the Pacific Ocean, would be particularly at risk, according to the map.

The United Nations’ Intergovernmental Panel on Climate Change (IPCC) projects that by the year 2100, global sea levels could rise by up to 3.6 feet if global greenhouse gas emissions are not mitigated. However, it says that a rise of around 6.6 feet “cannot be ruled out.”

The map by the National Oceanic and Atmospheric Administration (NOAA) allows users to see how different parts of the United States would be affected if sea levels rose by different amounts.

If sea levels were to rise by 3 feet, parts of Skagit County around the town of La Conner would be completely submerged in water.

The affected areas include those along the coast of the Swinomish Channel, which connects to Skagit Bay, Port Susan, and Livingston Bay. In the north, areas bordering Padilla Bay and Samish Bay would also be badly affected by the rising sea levels.

If sea levels were to rise by 6 feet, in line with the IPCC’s more severe projections, water would encroach further inland in these areas, and other coastal regions would also be affected.

Seattle would mostly be spared, except for the Terminal 18 container facility and some small areas along the coast, which would be submerged if sea levels rose by six feet.

Sea level rise is primarily caused by the melting of ice caps into the ocean due to warming temperatures. The level at which sea levels will rise will be impacted by whether global action is taken to slow climate change.

“Sea level rise will create a profound shift in coastal flooding over the next 30 years by causing tide and storm surge heights to increase and reach further inland. By 2050, ‘moderate’ (typically damaging) flooding is expected to occur, on average, more than 10 times as often as it does today, and can be intensified by local factors,” NOAA said in its 2022 Sea Level Rise Technical Report.

Assessing the state of Washington’s risks from sea level rise is made complicated by the fact that the land movement along its coast is highly variable, with some areas experiencing uplift while others are subsiding.

These variations are caused by movements of the Earth’s tectonic plates.

The state has been taking action to prepare for the potential impacts of rising sea levels, including through the three-year-long Washington Coastal Resilience Project. The project worked to identify at-risk areas and provide guidance to coastal communities, including several rural and tribal communities along the state’s coast.

The project also outlined the primary strategies for dealing with coastal hazards, including building hard defensive structures, using soft shore stabilization methods, using accommodation techniques to reduce flooding impacts, and avoiding development in risky areas.