Portola Valley may study retrofit of Town Center Portola Valley may study retrofit of Town Center (November 10, 2004)

By David Boyce
Almanac Staff Writer

Persistence sometimes pays off. A group of residents who oppose the demolition of a 50-year-old Portola Valley town building complex located in an earthquake rupture zone won a concession last week from a Town Council determined to rebuild in a safer location.

Councilman Ted Driscoll has asked the town's planner and attorney to quickly determine the legal and liability implications for modifying and continuing to use such buildings. The council may then accede to the residents' demand to have structural engineers estimate the cost of retrofitting the buildings to survive an earthquake.

The buildings' location in a rupture zone most likely triggers a state law that forbids adding floor space or occupants or making alterations worth more than 50 percent of the structure's value, said Town Planner George Mader. An exact legal interpretation is a job for the town attorney, he said.

Mr. Driscoll spoke during a November 3 council meeting at which a design team presented the final draft of a conceptual master plan to redo the 11.2-acre site. The councilmen -- all of whom said they like the plan -- may approve it at a November 10 council meeting, with discussions of financing options to follow.

"I want to pay respect to the (residents) who are entering this process late," said Mr. Driscoll. An engineering analysis could respond to the plan's critics and inform those who haven't been following the long community discussion that shaped the plan.

A 1972 analysis of the buildings -- done by San Francisco-based H.J. Degenkolb & Associates -- determined that reinforcement or alteration to survive earthquakes "would not be practical or feasible." Degenkolb may be called on for the new analysis as well, Mr. Driscoll said.

The analysis would include the costs of bringing the former school buildings up to contemporary building codes, including the federal Americans with Disabilities Act. The analysis would be done "in parallel" with the council's review of the conceptual master plan, said Mr. Driscoll.

Engineering v. science

The redesign of Town Center would -- for $13 million to $16 million -- put a new library, town hall, multi-use room and classrooms in a zone considered safe for human occupancy. Some athletic facilities would be relocated and a wide belt of tree-shaded open space created.

Opposition to the plan centers around four residents -- former mayor Bob Brown, Allan Brown, Charles Engles and Ed Wells -- who call themselves the Portola Valley Committee for a Safe Town Center and who support the idea of retrofitting the current buildings.

The committee recently mailed residents an opinion by retired civil engineering professor James A. Cheney, who said that the buildings could be made relatively safe by reinforcing them. Mr. Cheney also credits tree roots and compacted soil as deterrents to quake damage.

Mr. Cheney was invited to a standing-room-only November 3 meeting of the town's Geological Safety Committee, where he said that occupants of reinforced buildings would "go for a ride," but a quake "would not necessarily" damage the building or injure the occupants.

Geologists at the meeting said that engineering measures can protect buildings from ground shaking, landslides, liquefaction and tsunamis, but not against surface ruptures.

"The only mitigation for fault ruptures is to set back (the building) from the fault trace," said geologist Bill Lettis, who co-authored a 2002 report that found the buildings sitting in a rupture zone.

As for the protective qualities of tree roots, Mr. Lettis showed slides of surface ruptures adjacent to trees, displacing lines of trees, and splitting tree trunks.

Opinions aplenty

Many residents have been involved in helping to shape the master plan, and many have spoken out for and against it. Some were present at the council meeting.

The seven-digit price tag was a major concern for opponents, who see a retrofit as a low-cost alternative. "If you can show us credibly how much more you can get for the expenditure, the controversy wouldn't exist," said resident Bernie Bayuk.

Mr. Wells castigated the council for "rejecting" less expensive alternatives and noted that the project would span several elections, implying that voters would have the opportunity to change leadership.

Resident Virginia Bacon said the council has "put all our eggs into one basket," and would have liked formal consideration of Ford Field or the Nathhorst Triangle for town facilities.

Speaking in support of the plan, former mayor Jon Silver focused on the occupant safety issue. "If (the earthquake) happens during the daytime and these buildings fall on children in the library, this town will never forgive itself," Mr. Silver said.

"I'm opposed to seeing good money go into bad buildings," said former mayor Nancy Vian. "It's kind of like putting lipstick on a pig. ... We've been at this for 10 years. That's enough. Let's go."

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