Looking for the latest stories? We're now at cironline.org

Under pressure, state redraws quake hazard maps

Bryan Burns has been hounding school district officials about uncertified construction and fault zones near Pescadero HighYuli Weeks/California WatchBryan Burns has been hounding school district officials about uncertified construction and earthquake fault zones near Pescadero High School in Pescadero, San Mateo County.

In southern San Mateo County, two miles east of the Pacific Ocean, lies the blue-collar town of Pescadero, a tourist destination and geologic time bomb.

When resident Bryan Burns steps out his door, he sees Pescadero High School, and he’s gripped with worry. More landslides occur here than any other place in the state. Two dangerous earthquake faults, the San Andreas and San Gregorio, run through the area.

Burns has been hounding school leaders about the stability of the ground underneath the school, which opened at its current location in 1960, and about a county planning map showing a branch of the San Gregorio fault that has been ignored.

And Burns does not see any sense of urgency to do something about it.

“If the statistics are correct and the San Gregorio is as dangerous as the state says, somebody is going to get injured or killed over there,” said Burns, whose family sold the land where the high school was built.

The case of Pescadero High neatly illustrates the breakdown of California’s system regulating the seismic safety of its schools. Laws were overlooked and standards were lowered, yet the school has made building repairs without addressing potential seismic dangers.

Quake zones altered

A 1972 law requires the state to publish detailed maps of active earthquake fault zones. The California Geological Survey has amended those maps over the years, frequently shrinking the size of the hazard zones. The state has changed 161 maps out of 708, including one that carved a sharp angle around Pescadero High School in coastal San Mateo County. See a larger San Mateo County map.

Drag the green button in the center of the image to see differences between the maps.


Pescadero is just one school that found itself inside a fault hazard zone one day – and outside the next. California Watch found other examples of schools removed from hazard zones, including ones in the seismically active areas of Los Angeles and Alameda counties.

This loosening of standards came amid pressure from developers, real estate agents and local government officials who feared property values throughout California would decline, according to interviews and documents.

The state excluded scores of older, potentially active faults and narrowed the zones considered hazardous. Removing schools from the hazard zones was not the state’s central intent – but several ended up outside the lines when the new maps were published.

For parents, children and teachers living in areas prone to major earthquakes, the redrawn maps may provide a false sense of security.

In the town of Pescadero, the change was striking.

The old Franklin Point Quadrangle map from 1976 shows uninterrupted borders smoothly running north to south, outlining an earthquake danger zone. Pescadero High is firmly within that zone. On the newer map, created in 1982, the hazard zone takes a sharp right angle – neatly carving out a supposedly secure zone around the school.

“Faults don’t go at right angles,” said Peter Yanev, a World Bank earthquake engineer with 40 years of experience, who reviewed the maps for California Watch. “It doesn’t look right because faults don’t do this.”

The California Geological Survey has drawn 708 separate maps with one or more earthquake hazard zones on each. The maps are required by the 1972 Alquist-Priolo Earthquake Fault Zoning Act, passed one year after the Sylmar quake in the San Fernando Valley killed more than 60 people and caused at least $500 million in damage.

The law is considered important because it offers protection to people living in areas where earthquakes can break through the ground and upend buildings. Real estate agents are required to notify potential buyers about any fault zones on the property, a burden they have complained is too costly and can unnecessarily scare people.

And, more importantly, the Alquist-Priolo law requires school districts to hire geologists to make a detailed assessment of nearby earthquake faults before renovating or building in these zones. Builders, teachers, children and parents are left in the dark without those assessments.

Yet, several school districts in these hazard zones have started and completed construction projects in recent years without investigating fault-line hazards, records and interviews show.

Hazard zone maps draw backlash

As soon as the state geologist’s office released its hazard-zone maps in early 1974, groups with financial interests in property and economic development began to complain, according to records and interviews with earthquake experts working at the time.

Real estate agents saw the maps as a threat to property values. City and county officials accused the state of engaging in a massive government takeover.

“Quake Law May Devalue Property,” read a headline in the March 23, 1974, Oakland Tribune. The story warned that special geologic studies could cost as much as $5,000 for each building site in fault zone areas – about $22,000 in today’s dollars.

“Realtors absolutely hated it,” said Earl W. Hart, manager of the Alquist-Priolo program from its inception until the mid-1990s.

Hart faced skeptical crowds as he toured the state to explain the program. “As soon as I started my speech, their hands went up in the air. One guy yelled out, ‘When do we get to ask questions?’ ”

A review of state documents shows how the story unfolded over the next few years.

Notes from a State Mining & Geology Board public meeting in San Francisco in May 1974 highlighted the outcry: “The Division of Mines and Geology have received a myriad of problems, mostly by phone from property owners, cities, counties, banks, insurance and title companies.” Later, the board discussed how “property is being devalued, especially on active fault traces.”

In one three-week period, Hart reported receiving 52 complaints from real estate agents, developers, property owners and others. During the commotion, the state geologist at the time, James E. Slosson, refused to “water down” the hazard zone maps, notes from the State Mining & Geology Board show.

But in late 1975, Slosson resigned and was replaced by Thomas E. Gay Jr., who began re-examining the fault zone maps. By February 1976, the Fault Evaluation Program was born.

Hart’s team no longer included faults without significant ground movement in the past 11,000 years. Previously, the state had used the scientific standard of 3 million years – criteria still used by other states – to draw the zones.

Seismic experts say that it is difficult to predict when any fault, regardless of its age, will rupture again. And faults are hard to identify in urban and wooded areas without conducting field investigations. But Hart’s team did not perform any field investigations to locate faults because the Legislature had not allocated money for the job, records and interviews show.

The method of changing the maps has prompted concern.

Yuli Weeks/California WatchGeologist Gerald E. Weber concluded in 1980 that a branch of the San Gregorio fault may run under Pescadero High School in San Mateo County.

“I’m not sure I’d call it science, but it’s a technique that’s used,” said Gerald E. Weber, a private geologist whose research provided the foundation for the original Alquist-Priolo fault map covering the Pescadero area. “They have a system. I’m not sure I agree with it. And they may be underestimating the potential for some of these to have earthquakes.”

As a result of the changes, many fault zones shrank or disappeared from the Alquist-Priolo maps.

In the San Francisco Bay Area, 13 maps had fault zones that were removed, according to an internal state geologist report.  

As a result, two East Bay schools showed up inside hazard zones on the old maps and outside on the newer maps: Oxford Elementary in Berkeley and Riverside Elementary in San Pablo.

In Los Angeles County, the fault zone running through the wealthy town of San Marino was narrowed. Huntington Middle and Valentine Elementary schools, and all the houses and businesses surrounding them, suddenly were no longer covered by the Alquist-Priolo restrictions.

Out of 708 maps released over the past three decades, the state geologist’s office has redrawn 161.

Schools skipping geologic review

The Division of the State Architect oversees public school construction in California. Neither the division nor the state geologist's office said that they track schools in Alquist-Priolo zones.

"The problem is that there were so many schools built in those zones that it would have been embarrassing to tear them all down," said Patrick Campbell, a former chief structural engineer for the state architect's office. "So (the state) ignored it."

It’s unclear how many schools were within Alquist-Priolo fault zones before the maps were changed. But a California Watch analysis of state data shows about 90 schools now are situated within these zones.

Nearly all of the buildings at these schools were constructed before the law changed and the maps were created. But with the Alquist-Priolo program now in place, the state requires an investigation by a licensed geologist or geotechnical expert before starting renovations or new construction.

That’s because California law bans, with rare exceptions, any building from sitting within 50 feet of an active fault. No building can sit directly on a fault.

California Watch found schools within hazard zones that have made repairs without seeking review from a geological hazard expert. Bypassing that step could expose children to danger if the buildings were not fortified enough to withstand a significant quake or if the school were built too close to a fault.

“I’m sure there are faults out here. This area is full of faults,” said Bob Chrisman, superintendent of the Lakeside Joint School District in Los Gatos, south of San Jose. The district has made extensive renovations since 2000 to a multipurpose building at Lakeside Elementary. “But what can I do? This is California.”

No fault hazard studies have been conducted for Lakeside Elementary, according to a search of records at the California Geological Survey, the state Department of Education and the governor’s Office of Planning and Research. The school sits within an earthquake hazard zone on the Castle Rock Ridge Quadrangle in Santa Clara County.

Officials at Compton’s Vanguard Learning Center, which also sits inside a fault hazard zone, renovated buildings without a required fault-line study. 

Back in Pescadero, school officials made repairs to its roof in 2008 without a fault study, documents show. Although carved out of the state’s maps, San Mateo County rules still required the school district to conduct such a study.

Board controls mapping standards

Carlos A. Moreno/California WatchResidents who live near Pescadero High School in San Mateo County say school officials have ignored a hazardous earthquake fault near the school.

State Geologist John Parrish said the current maps are based on standards mandated by the State Mining & Geology Board, whose nine members are appointed by the governor and include a mixture of scientific experts. His office follows those standards. Strengthening them, he said, is a “social-political question” that he cannot control.

The state geologist and the staff at the California Geological Survey advise the board, which has final authority over the maps.

“We have to map according to the criteria laid down for us,” said Parrish, former executive officer of the State Mining & Geology Board. “It’s up to the board to define what is an active fault. We take our policy decisions from those definitions. We cannot map faults outside that criteria.”

To change the maps, state geologists did not conduct any field surveys. Instead, they reviewed available academic studies and aerial photos. They compared the information against the state’s criteria – including the 11,000-year quake standard – mandated by the State Mining & Geology Board.

The state geologist’s office has been preparing 15 new hazard zone maps, but the work has slowed because of budget cuts.

As for Pescadero High, Parrish said he would welcome evidence from the town or school district showing a potentially dangerous fault. If he’s convinced, Parrish said, he would redraw the Alquist-Priolo hazard zone to include the area.

Parrish added that builders, developers, real estate agents and local officials continue to complain about the maps to this day.

Hart, the former manager of the Alquist-Priolo program, maintains that the maps have been a success overall. In hindsight, however, he said the California Geological Survey may have erred by shrinking some of the earthquake fault zones.

Hart said that two state geologists, Gay, and his replacement, James F. Davis, agreed with his assessment at the time.

“I told my bosses that if we do this, we will be more efficient, but one day an earthquake could come and make us look bad,” Hart said. “Every time we discussed it, they said, ‘We believe in what you’re doing. Go ahead.’ ”

Reporters Agustin Armendariz, Chase Davis, Kendall Taggart and Anna Werner contributed to this report. This story was edited by Robert Salladay and Mark Katches. It was copy edited by Nikki Frick and Joanna Lin.


Comments are closed for this story.

via Twitter

© 2013 California Watch   /  development:  Happy Snowman Tech   /  design: