Bay Crossings Article

King Tides Send a Message: Get Ready for Climate Change

Deb Self
From the February 2012 edition of Bay Crossings

In the not-too-distant future, Sausalito and Marin City streets could be underwater twice a day. High tides could regularly overflow onto San Francisco’s Embarcadero. Around San Francisco Bay, storm drains will run in reverse, with salt water backing up in low-lying communities. Frequent flooding in winter will be the new normal. The more the world’s nations fail to agree on measures to stop global climate change, the more likely all of the above becomes. It won’t happen right away. Climate change is causing sea levels to rise gradually, over decades. But we can get a preview of what’s ahead, if we pay attention now to a winter weather event known as king tides.

King tides are exceptionally high tides that occur several times a year when the gravitational pulls of the sun and moon reinforce each other. Already, king tides are being exacerbated by the rising water level in the Bay, allowing us to understand where rising sea levels will impact the Bay Area first.

Visualizing what’s to come and identifying areas most vulnerable to flooding are the first steps toward coping with sea level rise. That’s why Baykeeper takes part in the California King Tides Photo Initiative. We’ll be out on the Bay in our 24-foot boat from February 6 to 8, taking photos and video of flooding caused by king tides. We’ll post those images on the California king tides website, along with images taken by California residents around the Bay Area and along the coast. You’re invited to take and submit photos, too. You can find out more at

The Bay Area needs to get ready for high water, because researchers predict that sea level rise will impact our region more than any other part of California’s coast. Under current estimates, by 2100, 270,000 people here will be at risk of flooding, along with $62 billion worth of shoreline development and infrastructure.

Over the coming decades, storm surges and regular floods will affect more and more shoreline areas. Low-lying pollution sources—such as wastewater treatment plants, landfills and industrial facilities located at or below sea level—will be at greater risk of contaminating San Francisco Bay. Wetlands, which now help filter pollution and buffer storm surges, may become completely submerged.

Smart planning for sea level rise now can avert damage later. It makes sense not to put thousands of new homes or massive commercial development on land that will be flooded soon. We also need to protect the Bay from pollution and to preserve wetlands wherever possible.

Crucial regulations governing development around San Francisco Bay are contained in the Bay Plan. The plan—put into place in 1969 to halt filling that threatened to turn the Bay into a narrow ditch—is administered by a state agency, the Bay Conservation and Development Commission (BCDC).

In 2009, BCDC took the eminently sensible step of announcing proposed changes to the Bay Plan to require development along the Bay shoreline to take future sea level rise into account. Baykeeper, along with other environmental groups, actively supported the BCDC’s proposal. But a select group of developers spent $350,000 on a high-powered lobbying campaign designed to stall and derail it.

One way Baykeeper countered this lobbying was to take BCDC staff members out on our boat to see last year’s king tides. The Bay was rough that day. Rain and wind made king tides rise even higher. Huge swells rocked our boat. We took a dramatic video of waves breaking over San Francisco’s downtown seawall and sloshing onto the Embarcadero. (You can see the video at Baykeeper’s website,

Despite developers’ intense lobbying, in October 2011 the BCDC voted unanimously: Sea level rise must be considered in future Bay Area shoreline development.

This new policy is a win for the Bay and for the environment. It makes the Bay Area a national model for action to cope with global climate change. I’d never claim that the only reason for the BCDC’s decision was our boat voyage during stormy king tides. But the more we all become aware of what sea level rise will bring, the more we can do what’s needed to protect San Francisco Bay and communities along the shore. Taking a realistic look at king tides is a good start.

Publisher’s Note: Bay Crossings strongly supports Baykeeper’s ongoing efforts to demonstrate that climate change is a real phenomenon with drastic global and local consequences, and we agree with BCDC that climate change issues need to be addressed sooner rather than later. We will continue to provide regular updates on how climate change will affect the Bay Area waterfront community.