A look at a tsunami's potential effect on the North County coastline

By: DENIS DEVINE - Staff Writer | Tuesday, January 11, 2005 2:06 PM PST ∞

NORTH COUNTY ---- If you live along the coast, the six-foot map hanging at the San Diego County's Office of Emergency Services depicts your worst nightmare.

It shows the North County areas most vulnerable to a 40-foot tsunami: Low-lying homes and businesses within six-tenths of a mile from the beach in Oceanside to Del Mar and along the San Luis Rey River basin.

But the map, modeled by some of the top tsunami scientists in the country, doesn't answer a key question: If a giant sea wave hits, where will all the people go?

No one knows.

As of today, no North County coastal community has mapped out its evacuation routes or simulated a coastal evacuation, though each agency has general emergency-response procedures and many have tsunami plans in draft form.

"You can never be ready for one of these things," said Denny Stoufer, superintendent of the state Parks San Diego Coast District, pointing to the catastrophe that struck South Asia two weeks ago. "It's of biblical proportions. How do you prepare for those things? There's a point of diminishing returns in preparation."

Low risk, but big threat

The chances of a tsunami striking San Diego County's shores are slim, especially one with the destructive force that pummelled South Asia on Dec. 26. The 40-foot waves anticipated on the state's emergency planners' map are higher than most of those that radiated throughout the Indian Ocean basin.

Local coastal communities shouldn't breathe too easily, however: A tsunami generated by a landslide along the San Clemente fault 50 miles southwest of Point Loma could wallop the local coast within 20 minutes, too quickly for emergency plans to do much good.

Moreover, because the tsunami threat has taken a back-seat to earthquakes, wildfires and homeland security threats (think terrorism and weapons of mass destruction), local agencies have not run drills or simulations of a coastwide evacuation, nor have they mapped out their evacuation routes.

Emergency planners have been playing the odds, but tsunami preparations figure to get a boost from increased public interest spurred by the deadly Asian tsunami.

Flood maps prepared

San Diego County's coastline has never been evacuated for a tsunami or a hurricane, though state parks lifeguard superintendent Denny Stouffer remembers a near-miss with a hurricane about two decades ago.

The Office of Emergency Services' map bubbled up from a National Tsunami Hazard Mitigation Program created in 1995, which provided about $2.3 million each year for the West Coast's five states (including Hawaii and Alaska) to map the communities at risk along their coasts.

The University of Southern California's Tsunami Research Group envisioned a wide variety of distant tsunami and near shore, underwater landslide scenarios slamming the Southern California coastline, then drove the coast and walked many beaches to further hone their models. The resulting map clearly represents a worst-case scenario no researcher involved believes likely.

The county's emergency coordinators are now forwarding that map to coastal cities so they can create evacuation routes and procedures.

Jim Phelps, one of the county Office of Emergency Services coordinators, said cities have had some practice in clearing crowds from the coast.

"As far as evacuations go, a lot of the beaches do it every July 4th when they have fireworks," he said.

But eastbound gridlock on Independence Day can't compare with the chaos that likely would follow a serious tsunami warning.

Notification

If an earthquake of magnitude 7.1 or greater occurs somewhere in the Pacific Ocean, that warning would be issued by one of the National Weather Service's tsunami warning centers in Alaska or Hawaii within 15 minutes. The warning spreads via the Internet with a speed that outpaces the tsunami itself.

The San Diego office of the National Weather Service would instantly receive and relay that message to dozens of other agencies. California's Office of Emergency Services would immediately notify first responders throughout the state, including the San Diego County Sheriff's Department, the state Parks Department dispatch center in Lake Perris, the North County Rancho Fire Communications Center and other North County fire dispatchers, who in turn would then page or radio their personnel and member agencies.

Redundancy is built into each step of the warning chain. Aside from the numerous e-mails, the National Warning System, a Maryland-based telephone party line dating back to 1950s-era fears of a nuclear attack, would alert emergency contacts in local governments via an old-fashioned phone call.

Within a 10-mile radius of San Onofre Nuclear Generating Station, 49 sirens would blast their own deafening warning.

The National Weather Service also automatically generates a warning on weather radios popular among fishermen and surfers; the radios can be set to turn on when such an alert is issued.

Near vs. far

North County's response would vary greatly depending on whether the tsunami was generated by a near or distant seismic event, local officials said. Many procedures in place for a tsunami generated by a faraway earthquake are worthless if the waves are kicked up by a near-shore landslide.

In the event of an imminent landfall, the Emergency Alert System ---- that purposely obnoxious screech of a test many routinely ignore ---- would broadcast a warning across all TV and radio stations encouraging the entire coast to seek higher ground. Radio station KOGO receives the signal from the county Office of Emergency Services, and then broadcasts the warning to all other stations.

But if the tsunami is due in several hours, the county's emergency staff would call and page TV and radio stations themselves.

The difference is also apparent in evacuation plans.

State parks and city lifeguards would clear the beaches on foot and tires once they are notified of an approaching tsunami ---- first people, then equipment. State parks lifeguards would close their coastal campgrounds in Carlsbad and Encinitas and make inland campgrounds available for people by the evacuation and tsunami, officials said.

Encinitas lifeguard Capt. Larry Giles said lifeguards would be on the beach evacuating people and equipment if the tsunami came with advance warning, and shift to search and rescue after the waters had receded.

But ---- reflecting the difficult, quick decisions a locally generated tsunami would require ---- he added, "If it's actually happening, we'd probably just evacuate as many people and staff to get them out of there. It wouldn't do anyone any good to get us taken out, because there won't be any people left to rescue anybody after it's over."

Support from above

Air support would be vital should San Diego County need to flee its beaches. Helicopters from the U.S. Coast Guard, state Highway Patrol and Department of Forestry, San Diego Fire-Rescue Department, and San Diego County Sheriff's department would scramble and assist in warning coastal residents and visitors to seek higher ground. Choppers may also be able to rescue some people being swept out to sea by dangling rescuers on ropes.

North County's cities would take control of notification, evacuation and rescue operations within their borders. In the unincorporated parts of San Diego County, chief administrative officer Walt Eckard would be in charge, said Phelps in the county's Emergency Services office.

In addition to lifeguards and sheriff's deputies notifying people within the inundation zone, city officials would attempt to coordinate an evacuation from the coast.

Getting high could save your life

Planners worry about traffic congestion, especially if an inconsiderate tsunami were to arrive around rush hour. But they hope San Diego's mostly steep shoreline minimizes that problem: "Keep in mind, you only have to get about a half mile away," said Phelps. The CHP could also direct all traffic on the freeways eastward away from the coast.

Moreover, the county emergency coordinator said distance from shore was less important than getting people to high ground.

"We're concerned about getting everybody in their vehicles and out on the roadway, and then the water is going to be coming up over the roadway, as opposed to telling people to get to high ground," Phelps said.

San Diego County's rescuers are more prepared than ever to tackle a regionwide disaster like a tsunami. Last summer, coastal rescue agencies joined together to form SDR ALERT, or the San Diego Regional Aquatic Lifesaving Emergency Response Taskforce.

Representatives of the U.S. Coast Guard, U.S. Border Patrol's Marine Division, San Diego County Sheriff's department's emergency response squad, Oceanside Harbor Police, and lifeguards from San Diego, Encinitas, Camp Pendleton, Coronado, Del Mar, Imperial Beach, Oceanside, Solana Beach and the state parks are meeting monthly to discuss coordinated responses and joint training for water-related emergencies, including tsunamis.

Protection or access?

Meanwhile, preparing for a tsunami could force North County to make touch choices.

If seawalls that can withstand the brunt of a 40-foot-high tsunami surge are built, Californians might lose their ability to see their beloved beaches. The standard used throughout Japan are walls about 33 feet high, the same height of the thick seawall protecting San Onofre's nuclear reactors. That's also the maximum-allowed height of the roof of any beachfront property approved by the California Coastal Commission.

"If we would design the coast for tsunamis, we would wall off the coast and not be able to see the shore," said David Skelly, an Encinitas-based coastal engineer.

Contact staff writer Denis Devine at (760) 740-5415 or ddevine@nctimes.com.

Stay safe in a tsunami:

If water starts to recede unusually, don't indulge your curiosity and go closer to inspect it; head for high ground.

If you feel an earthquake of sufficient enough force that it gets tough to keep your footing, head for high ground.

If you live or work near the coast, buy a weather radio. They will turn on in the event of a weather emergency like a tsunami warning.

Stay out of the coastal zone for at least three hours after the first big wave strikes the shore.

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