King Tides a Preview of Coming Sea Rise

John Laird
December 24, 2013

Truck drives through flooding bay waters at hwy 1 off-ramp in Marin County Dec 2013
A truck drives through flooding from bay waters at a Highway 1 off-ramp in Marin County last December as sea levels rise. Photo: Brant Ward, Associated Press

Sea levels off the California coast will rise up to 2 feet by 2050 and up to 5.5 feet by 2100, scientific research suggests. Already, sea levels have risen in San Francisco by 8 inches over the past century. The highest tides of the year – dubbed King Tides – will be experienced here from Monday through Jan. 2, and again from Jan. 29 to 31. These tides offer us a preview of what will happen as sea levels continue to rise. King Tides occur when the tilt of Earth’s axis and the magnetic pull of the sun and the moon are aligned.

During last year’s King Tides, citizen scientists documented high water levels along the Embarcadero in San Francisco, in Mill Valley streets, on a major freeway off-ramp, and at some Northern California beaches. The tides submerged portions of bike paths, beach access points and other critical low-lying infrastructure. The rising sea level threatens to damage property, increase landslides, flood beaches and wetlands, and cause saltwater to intrude on our groundwater.

We need to adapt to these rising seas sooner rather than later to avoid huge losses to our coastal communities. In response, a partnership of state and federal agencies and nonprofit organizations launched the California King Tides Initiative to raise public awareness and build support for actions to reduce climate risks.

The King Tides Initiative asks citizens to document these high tides by photographing flooding in their communities. The photographs provide coastal managers important information on the most vulnerable areas.

The State of California has also just released the draft Safeguarding California Plan, which outlines key actions needed to prepare the state for the effects of a changing climate. Implementing these actions now will help us cope with changes in the future.

We know that even at the lower estimates of sea level rise, San Francisco International Airport would be completely inundated. Much of downtown Monterey and crucial wetland habitat at Elkhorn Slough would be flooded.

It often takes a catastrophic event to catalyze action. We are feeling the impacts of sea level rise today, and now is the time to prepare.

John Laird is California’s secretary for natural resources. For more information on the King Tides Initiative, go to