The frantic, sometimes scattered response of Bay Area firefighters and police immediately after last week's earthquake told Ventura County emergency teams where they will succeed and where they may fail when the "Big One" strikes Southern California, an event seismologists say is probable in the next 30 years.
Scores or hundreds of people may be injured or killed in the county, and its supply of ambulances and paramedics would quickly be exhausted, drawing firefighters away from burning homes and businesses. Bridges and highways could buckle and any of the four major area dams whose waters would course through county riverbeds could fail.
The old unreinforced masonry buildings of downtown Ventura, Ojai, Santa Paula and Fillmore may crumble into piles of rubble like the remains of structures in Santa Cruz. Homes in Ventura County's older neighborhoods might slide off their foundations.
And the county's fertile sandy soil, long an asset in this productive region, could become a deadly liability. As in Santa Cruz, the areas with shallow water tables near the coast or along river beds would shake with up to 10 times the intensity of more stable areas. In some regions, the turbulent water beneath the earth would shake so hard that the soil would become like quicksand.
"We're looking especially at the Oxnard Shores area because it is sandy soil and fill-in," said Karen Guidi, assistant director of the county's Office of Emergency Services. The Ventura Keys and other marina areas will also be exceptionally vulnerable, she said.
Nevertheless, Ventura disaster officials believe that their preparations over the 17 years since the Office of Emergency Services was created will stand them in good stead when an earthquake hits.
"I feel confident that we will be equally as capable or more so than the Bay Area to respond to a major disaster," said Ventura County Fire Chief Rand-Scott Coggan.
Coggan was part of a four-man team that toured San Francisco and Santa Cruz following the Oct. 17 temblor that registered 7.1. He assessed Ventura County's state of readiness before the Board of Supervisors on Tuesday.
Despite the county's preparations, reactions by Bay Area emergency crews showed Coggan that more work is needed here.
For instance, better provisions must be made to transport the injured, he said.
In Ventura County, 12 to 15 calls will use up the available ambulances, and firefighters will have to fill in for paramedics and ambulance drivers. Even that may not be enough.
"We saw the San Francisco Fire Department, as big as they are, using taxis to transport people to the hospital," he said. Water mains will break here as they did in the Bay Area, decreasing water pressure in hoses, Coggan said. In San Francisco, the Fire Department pumped 9,600 gallons of water an hour from its special fireboat in the bay to douse the Marina District fires.
But no such expensive tool is available to Ventura County, and firefighters will have to save homes at the expense of businesses, Coggan said.
"From the standpoint of residential fires, we can rely on swimming pools and aerial tanker relays, but from the standpoint of commercial fires, they will not do us a whole lot of good," Coggan said.
A strong earthquake along the San Andreas Fault, which touches the county near Tejon Pass, could cause failure at major dams, including Pyramid or Castaic, pressuring the smaller Bouquet and Bard reservoirs and Santa Felicia dam at Lake Piru.
If all were full and all failed, a worst-case scenario that officials say is unlikely, the quake could unleash up to 551,000 acre-feet of water, according to county figures. The 15,000 people in Fillmore and Piru would have less than 30 minutes to find higher ground, and Oxnard would have only two hours to prepare for a three- to six-foot wall of water, Guidi said.
Although the dams have passed recent state inspections, and both of the larger Pyramid and Castaic dams were built to withstand major earthquakes, Guidi said, residents still need to be informed of the possibility that the dams could rupture.
"There are thousands of people who are living in the flood plain and dam inundation areas, and they need to know that they would have to evacuate quickly," she said. Failure at the 30-year-old Casitas Dam below Ojai, with a capacity of 254,000 acre-feet, could flood the Casitas Springs area in 30 to 40 minutes and the Ventura Avenue area in an hour.
Bridge and road failures could make evacuations more difficult, especially in mountain areas. Heavily traveled California 33 in the western part of the county and Grimes Canyon Road in the east would move with the fault-fissured earth beneath them, officials said.
"The roads are only as stable as the country they go through," said Jack Hallin, state Department of Transportation project design manager for Ventura County. He acknowledged that there are faults beneath county roads, just as there are faults beneath the state's major highways.