Coastal Areas Prepare For The Other 'Big One'

California has just completed a landmark effort to assess the state's worst-case tsunami danger. Now emergency response officials, and even some planners, are considering how to keep the state's coastal populations safe.

1 minute read

March 13, 2010, 7:00 AM PST

By Josh Stephens @jrstephens310


"Approximating maximum inundation for a worst-case scenario tsunami, the line washes over all of Newport Bay and Marina del Rey, wipes out parts of downtown Santa Cruz, and makes half of Seal Beach disappear. Some of the state's most fabled real estate from La Jolla to Malibu to Montecito would wash out with the tide. It would yet again pummel Crescent City, itself the victim of the nation's most destructive and deadly recorded tsunami, a 20-foot wave that struck on Good Friday, 1964."

"The maps assign to the tsunami threat a visual element that is absent from the prediction of earthquakes. Contrary to this discomfiting picture, however, researchers and state officials alike caution that the maps' projections in no way mean that the state's coastal communities and nearly 1 million coastal residents should permanently decamp for higher ground."

"Memories of the 2004 south Asian tsunami -- and of the statewide warnings that were sounded after the February 25 Chilean earthquake -- make clear the destructive threat of tsunamis. The maps were prompted by recommendations in a 2005 risk assessment report published by the state Seismic Safety Commission. That report, which was prompted by the south Asian event, noted that roughly 80 tsunamis have struck California over the past 150 years and that two of them were destructive."

Thanks to Josh Stephens

Wednesday, March 10, 2010 in California Planning & Development Report

"Planetizen federal action tracker" logo superimposed over black and white image of US Capitol dome.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

October 28, 2026 - Zachary Whalen

A car drives through a puddle, making a large splash. Rain pours down.

California plans to bury El Niño’s downpour

If the state plays its cards right, it may be able to store a billion acre-feet of El Niño’s water in aquifers.

October 28, 2026 - Grist

Lake Powell with much of the water evaporated.

Desperate measures: Advocates weigh draining Lake Powell to fill Colorado River

Draining the reservoir could reduce evaporation losses by a couple hundred thousand acre-feet.

October 30, 2026 - Yale Environment 360

Mamdani behind a microphone, in front of a snowbank

Mamdani’s pied-à-terre tax survives legal challenge

A panel of judges found that the plaintiffs failed to demonstrate injury as a result of New York City's implementation of the tax.

November 6 - CNN

A road in north eastern Nebraska with power lines on either side, and grassy fields.

Eastern Nebraska is running out of electricity

Data centers and electrification are straining eastern Nebraska’s grid, throttling economic development.

November 6 - Grist

People board a bus in Seattle.

Seattle passes record-breaking transit services expansion

Proposition 1 will double the city’s transit tax to add 95,000 more bus trips and preserve 180,000 bus trips annually.

November 6 - KOMO News

FREE Course: Walkable City 1: Why Walkability?

After describing his path towards focusing on walkability as the essence of good planning, Jeff Speck marches through his five principal reasons for making more walkable places.

Reinventing Malls: Planning Alchemy—Turning Gray Fields Into Gold

The course focuses on the opportunities and imperatives that shape reinvention of mall sites.