http://paloaltoonline.com/blogs/p/print/2011/03/18/on-deadline-could-a-quaketsunami-hit-palo-alto-east-palo-alto-menlo-park-you-bet


Local Blogs

By Jay Thorwaldson

On Deadline: Could a quake/tsunami hit Palo Alto, East Palo Alto, Menlo Park? You bet

Uploaded: Mar 18, 2011

In the shadow of the double-whammy disaster in Japan (assuming nuclear meltdown doesn't make it a triple) the inevitable question is: Can it happen here?

Well, sure.

It doesn't take much of a stretch of the imagination to envision (1) a big shake on the Hayward Fault, deemed at highest risk for a big shakeout, just ahead of the infamous San Andreas; (2) a surge of water moving down the bay; (3) a wind pushing the surge; (4) a high-tide -- they happen twice daily; (5) a rainstorm that has filled local creeks; and (6) a power outage that stops Palo Alto's pumps (remember the El Nino storm of February 1998?).

One hopes, of course, that those conditions never line up. But there's always Murphy's Law: "Anything that can go wrong, will. ..."

The possibility of really really bad things happening right here at home is "old news" in many ways. There are scores of people, perhaps hundreds, involved in one way or another in trying to get Palo Alto and surrounding communities better prepared for earthquakes, floods and other natural or man-made disasters -- the big kind that impact the entire city or region.

Advances have been made, such as improved communication systems between agencies and a fast telephone dial-up warning or alert system. Yet citizens and officials involved are the first to admit that the community is far from being truly prepared.

Neither neighborhoods nor families nor individuals are ready in terms of having adequate emergency drinking water and food set aside, adequate emergency First Aid kits, enough training, "Go Boxes" for their most precious possessions and papers, or a neighborhood or family emergency plan.

The news that the bay may pose a disaster threat also is pretty old.

In 1975 I wrote a piece for the former Palo Alto Times reporting a study that cited an urgent need to rebuild the levees surrounding the South Bay, most from the building of salt ponds over the decades. Pumping out groundwater for the fast-growing Santa Clara Valley was causing the land to subside, and that included a drop in levee height of up to 5 or 6 feet. (Subsidence has since been halted by percolation ponds that maintain the underground water table.)

But sea level stayed the same, putting the entire South Bay at greater risk of serious high-tide flooding.

The 1975 estimate to rebuild the levees was $95 million, a paltry sum today but real money a third of a century ago.

Then engineers came up with a better idea: Rather than rebuilding the twisting, in-and-out levees on the bay side of the wetlands and salt ponds they proposed building a concrete wall on the landward side, much shorter. This idea horrified those who loved the view of the wetlands and the bay, and the idea was stomped to death.

To my knowledge, there has never since been a region-wide repair of the levees, although work has been done here and there.

And a new concern has arisen: a possible rise in sea level due to global warming -- now accepted as real by most independent climate scientists around the world. A conservative estimate is that within 50 years there would be about a 2 foot 2 inch rise in sea level, which also means "bay level." Some projections are worse, including up to a 55-inch rise.

Two feet doesn't sound like much, but it would be equivalent to the feared "100-year flood," the common standard used for flood preparations (meaning a flood with a 1 percent chance of occurring in any given year). A 2-foot sea level rise would be equivalent to a fairly typical high tide of today -- then would come the tide.

Should the bay overtop the levees, or if the levees fail under storm battering, large areas of Palo Alto, Menlo Park and East Palo Alto would be subject to flooding. People pretty much know where the water would go in Palo Alto based on the 1998 flood, when the storm-swollen San Francisquito Creek overflowed. In addition to the main overtopping at the Chaucer Street Bridge there were 17 other spots reported on both sides of the creek, where water slopped over into all three communities.

The Bay Conservation and Development Commission (BCDC) has issued a flood-risk map, and the Pacific Institute also recently issued such a map showing both the 100-year flood zone with a 55-inch rise in sea level added in dark blue. Both maps show immense areas of the cities being submerged, clear to Louis Road and beyond in Palo Alto.

How deep? There were deep waters in parts of Palo Alto in 1998, as firefighters rescued people from homes. Yet mostly the water was wading level, and rose slowly, not in a big surge.

The worst local threat is to East Palo Alto's low-lying Gardens neighborhood, where several hundred homes could be inundated by up to a potentially deadly 8 to 10 feet of water. The Weekly called it a potential "mini-New Orleans" in an editorial following Hurricane Katrina -- helping free up stalled federal funding for continuing a study of flood threats from the creek.

For many years the battle over how to make the creek safer has churned between the communities, until the San Francisco Creek Joint Powers Authority brought the three cities and two counties together more than a decade ago.

The threat from the bay has mostly been ignored, however.

No longer. Len Materman, the executive director of the creek JPA, has repeatedly called attention to the possible "other source" of flooding. And things are moving at last.

A major study of the flood potential and what might be done to protect the communities is due out by June 1, sponsored by the Army Corps, the Santa Clara Valley Water District and the Coastal Commission. But Palo Alto's bayfront won't be part of that, the Corps and water district decided March 8. They shifted the study's priority to more vulnerable areas -- such as Alviso.

Materman says the JPA may be able to pick up the Palo Alto portion, which would cover from San Francisquito Creek to the Charleston Slough just south of Palo Alto. The creek and tides are tightly connected. Menlo Park and East Palo Alto shorelines are already being studied and some work has been done in Palo Alto.

Meanwhile, a major emergency-preparedness "fair" is being planned in Palo Alto for Sunday, May 1. Check http://www.paneighborhoods.org/ep .

An e-mail announcement says it all: "It can happen here. This is another wake-up call."

At least we have no nuclear plant.

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