Are you ready for the next big one?

By Les Earnest <les@cs.stanford.edu>

Los Altos Hills resident since 1965

 

October 2010

 

My neighborhood isn’t prepared, unfortunately.  Have you thought about yours?  This note reviews emergency access issues in the Town of Los Altos Hills and recommends that a Town task group be set up to study and make recommendations on the following five questions.

(1)  Which neighborhoods without an emergency access route should have one?

(2)  Which existing emergency access routes need to be restored?

(3)  How can people get through locked gates in an emergency?

(4)  Should a new class of emergency access road be recognized that provides access for ambulances and private vehicles but not necessarily for fire trucks?

(5) What can be done to mitigate the potential collapse of freeway overpasses that could cut the Town in two?

 

The beautiful setting of our town is a product of millions of years of seismic activity that has uplifted the hills around us.  There have been millions of storms that have eroded these hills and periodically flooded certain areas.  Lightning and human activities have caused major fires to sweep through the hills, including a big one in 1985.  There is no question that our Town will be buffeted by cataclysmic events in the future.  The only questions are:

  • What will happen next?
  • When will it happen?
  • What reasonable precautions can we take to prepare for it?

The first two questions are currently unanswerable. The third one we can and should address. However there is a human tendency to avoid thinking about catastrophes except just after one has occurred.  I offer below some stories that illustrate why we should “think about the unthinkable.” Then I will say a few things about each of the five questions at the beginning of this note.

 

When privacy and safety conflict

Our Town’s road system, which has few through roads and lots of cul de sacs, provides a quiet residential environment but poses serious problems when roads get blocked.  For example, my O’Keefe Lane neighborhood has 73 residences on seven connecting streets with a combined length of 1.75 miles but there is just one way in and out and no emergency access road.  O’Keefe Lane has been blocked about six times during my 45 years here, either as a result of Purissima Creek flooding or from fallen trees caused by storm conditions.

 

Fortunately none of those closures lasted for more than a day, no houses caught fire during those periods and, as far as I know, no one in the neighborhood needed emergency hospitalization during periods of isolation.  However, when O’Keefe gets blocked as a result of a major earthquake, as likely will happen sooner or later, we may not be able to get outside help to reopen it as in the past and there will be a strong likelihood of injuries and fires resulting from the collapse of structures, landslides, fallen power poles and uprooted trees.  As things stand we will be up a creek (called Purissima) without a paddle.

 

The early residents of my neighborhood chose to isolate themselves, I suspect without giving much thought to safety issues.  Below is an aerial photo of our neighborhood in 1964, provided by my former neighbor Sam Jackson.  That was just before I arrived and before construction began on the freeway.  As you can see, apricot orchards still dominated the area but the recently constructed Foothill College parking lot appears in the upper left part of the picture.  The freeway was built later just below the parking lot, crossing the pictured area from left to right.

 

 

There had been a road connection from our neighborhood, in the lower part of the picture, to Josefa Lane, next to the parking lot, and the college had advocated building a freeway underpass to provide a secondary access to their parking area.  However residents in my neighborhood objected and that proposal was scrapped.  Thus since the freeway was completed there has been just one way in and out of our neighborhood, a situation that I believe needs to be fixed.  I know of five potential emergency access routes and believe one should be selected and made to work.

 

The last big barbeque

Many of us have seen the effects of runaway fires, such as the one on July 1, 1985 that destroyed about a dozen homes in the Liddicoat Drive neighborhood.  That fire was started on Arastradero Road just west of Town, near a Stanford computer research laboratory where I worked for 14 years and was apparently set by an arsonist who wanted to see that laboratory burn. An account of this horrific incident, with pictures, can be seen here

 

After the fire, Palo Alto removed the remains of the trees along both sides of Arastradero, turning it into a very ordinary looking road but ensuring that there would not be an exact repetition of that holocaust.

 

Shake, Rattle and Roll

This part of California has been shaken by major earthquakes countless times in prehistory and a number of times since the European invasion.  Native Americans who lived here earlier probably coped pretty well inasmuch as their homes were mostly built of light materials.  For us, fractured chimneys, falling bookcases and other toppling furniture can do serious damage, not to mention what can happen if the house itself collapses, gas lines break or power lines fall.

 

The most recent quake that did much damage here was the October 17, 1989 magnitude 7 temblor centered under Loma Prieta Peak in the Santa Cruz Mountains.  It did major damage from Salinas to Oakland and San Francisco, causing buildings, bridges and freeway structures to collapse and taking quite a few lives.  It also stopped the remarkable World Series baseball game between the San Francisco Giants and the Oakland A’s that was about to begin in Candlestick Park.

 

Locally, about ten homes were destroyed in the La Cresta Drive neighborhood.  A tower collapsed at St. Joseph’s Seminary just south of Town, killing one person, and a number of compression features showed up all over Town.  A cement retaining wall along highway 280 was crunched like an accordion and the roadway buckled upward south of Magdalena, making it impassible for a time.  A small ridge appeared across my street, Dianne Drive, that is still there.  Happily the only damage to my home was a slightly cracked chimney.

 

The 1906 earthquake was a much bigger deal.  It released about 16 times as much energy as Loma Prieta and had an estimated magnitude of 7.8.  Faults appeared at the surface from near Salinas to Shelter Cove in Mendocino County and the land west of the fault lurched northward up to 20 feet in 4 or 5 seconds.

 

The movement here was less than to the north but it broke a fence line just west of what is now our Town and severed Page Mill Road at a point where it now goes through a big dip.  There were only a few people here at that time, so the extent of damage was much less than in San Francisco, where massive building collapses were compounded by a runaway fire, killing many people.

 

Some geologists expect that the next sizable earthquake here will come not from the San Andreas but from the Hayward Fault just across the Bay, which could produce a magnitude 7 quake at any time.  However there are other dangerous faults in this area, possibly including some that we don’t know about yet.

 

When the next “big one” comes, many of us will be on our own to get out of collapsed structures and blocked roads.  I and my neighbors may be able to get out of the area on foot via pathways or through open space but those who are disabled will be in serious trouble.  If there is widespread destruction in this area, we would be much better off if we could get out with a personal vehicle and travel out of the devastated area.  However, as things stand, I and my neighbors may not have that choice.

 

Which neighborhoods without an emergency access route should have one?

As recommended above, I believe that the O’Keefe Lane neighborhood should have an emergency access road.  The Sunset Drive neighborhood just to our north also looks very vulnerable.  It has 28 residences distributed along two ridges with grassy slopes on all sides.  Those streets are very narrow and there currently is no emergency access route.  However, there is an existing road right-of-way linking the ends of East and West Sunset that could provide emergency access with a bit of grading so as to reconnect them as they were in the 1940s.  It appears to me that should be done.

 

More generally, I believe that the Town should formulate a policy on where emergency access roads should be provided, perhaps based on the number of residences and their distance from the nearest road with more than one way out, and it should be used as the basis of a systematic Town-wide review of where else emergency access roads are needed.

 

Which existing emergency access routes need to be restored?

The photo just below shows a place where there is supposed to be a 20 foot wide emergency access road with a 10 foot pathway in the center, but an adjacent landowner has built a gated driveway on the emergency access easement and pushed the pathway to one side with a 2 ˝ foot tread below a wooden retaining wall that is in the process of collapsing.  I believe the emergency access road should be reopened and the pathway restored to its 10 foot width..

 

More generally, I believe that the Town’s existing emergency access routes should be reviewed periodically to ensure that they are maintained in a usable state.

 

How can people get through locked gates in an emergency?

In parts of Town where emergency access roads exist, most have locked gates or chains.  Here is an example of a padlocked gate where not even a pedestrian could get through to the emergency access road behind.  Besides, there is another padlocked gate at the other end.

 

 

This does not pose a problem for the fire department because they have keys in most cases and also carry more versatile “keys:” bolt cutters capable of cutting chains or locks.  In some cases local residents have been given keys or have been permitted to put their own lock in series with the others. However we should consider what will happen in a serious emergency. Will residents be able to find the right key? What if the person in the family with the key is incapacitated.  What about visitors?

 

Unfortunately the right solution involves a political hot potato:  I believe that all barriers on emergency access roads should be openable without a key.  This will permit some abuse, of course, but the alternative is worse.  It would be reasonable to post a sign at each access point saying something like this and enforcing it.

Vehicular access

only in emergencies.

Fine for misuse $$$$

The current practice of keeping these routes locked is equivalent to requiring buildings to have emergency exits but allowing them to be padlocked, as has tragically happened in a number of historical cases.

 

A possible mitigation would be to use breakaway locks on emergency access routes. These locks have weakened hasps that allow them to be broken with a hammer or a large rock. However the need to find a suitable smashing device, which may not be handy, and the likelihood that some people will not have the strength to do it argues in favor of leaving emergency access routes unlocked.

 

Should a new class of emergency access roads be recognized that provides access for ambulances and private vehicles but not necessarily for fire trucks?

One barrier to creating new emergency access roads is that current Town standards require a width of at least 20 feet and in some cases a bit more in order to accommodate fire trucks.  While that standard should be maintained for new subdivisions and elsewhere whenever possible, getting that much new right-of-way may be difficult in established neighborhoods.

 

For such cases, I believe that consideration should be given to creating a “Class 2” emergency access road that is wide enough for cars and ambulances to get in and out.  A width of ten feet would suffice, which means that pathway easements could be used.  In order to accommodate this, it would be necessary to modify the Circulation Element of the General Plan.  I suggest that this possibility be reviewed by the prospective Emergency Access Task Force.

 

What can be done to mitigate the potential collapse of freeway overpasses that could cut the Town in two?

The 280 freeway bridges in our town were built in the same era and to the same standards as those that collapsed during nearby earthquakes in Sylmar in 1971, in Oakland in 1989, and in Santa Monica in 1994. In a strong shake it is likely that some spans will come down, which would not only sever the freeway route but will also block the roads underneath such as Magdalena, El Monte and Page Mill Roads. I believe that our town should develop a plan for dealing with this problem.

 

One possible mitigation would be to put gravel strips across the freeway medians just beyond where on-ramps connect, which in case of a bridge collapse would allow vehicles to go up the on-ramp, do a U-turn across the freeway and come down the off-ramp. Of course, getting that done would require the cooperation of Caltrans.

 

Conclusion

I recommend that an official Town task group be formed and charged with reviewing and making recommendations on the five questions given at the beginning of this note as well as other emergency preparedness issues. After that I hope that there will be some action on fixing the problems.  Perhaps we can get it done before nature preempts us.

 

Acknowledgement

Thanks to Mike Sanders, Emergency Services Coordinator of the County Fire Department, for suggesting the breakaway lock idea.

Chronology of attempts at addressing emergency access issues