The California Geological Survey is in the process of “zoning” the Hollywood Fault as part of the agency’s Alquist-Priolo Earthquake Fault Zoning Act program, and the results are expected in the next few weeks.
State Geologist John Parrish said the survey had planned to “zone” the Hollywood Fault at the beginning of 2014, but expedited the work to assist the city of Los Angeles in its decision regarding the Millennium Hollywood project.
“We wanted to get the information to the city as soon as possible,” he said, adding that the zoning could require some “pretty thorough” site investigations for any building designated for construction within the zone. However, Parrish couldn’t specify whether the state analysis would impact the project, which was approved in July.
Parrish said a “much more thorough” study would need to be conducted to map exactly where the fault lies on the project site. Digging a trench, as the developers have agreed to do, would satisfy that need, he said.
“That’s the kind of definition that is necessary,” Parrish said.
He said the developers would need a third-party confirmation for their next level of testing. In most cases, that third party is the California Geological Survey, Parrish said.
“We always asked to be invited to the sites, and we almost always are,” he said.
Parrish said the agency opted to pen a letter to the Los Angeles City Council after staff members in its Los Angeles field office, who had been following the project for “awhile,” alerted him about the upcoming vote.
“They just felt that the Hollywood fault issue didn’t seem to be discussed in the planning stages — at least publicly that they were aware of,” he said, adding that the project was “pretty far along” by the time staff members learned of it. “We think there is evidence of faulting throughout the area. Whether the faulting runs underneath the Millennium project site is what we are attempting to define. We don’t believe any studies that have been so far been made available to us indicate that the fault does not go beneath the properties.”
Therefore, the geological survey wanted council members to know that the upcoming zoning could contain information that would be “very pertinent” to their deliberations, Parrish said. He said the letter was simply a notice, and reiterated that the non-regulatory agency got “into the picture late.”
“It’s up to the city to decide,” Parrish said. “They’re the ultimate decision makers on how to proceed on these things.”
The state geologist said the Alquist-Priolo Act aims to provide lead agencies, such as the city of Los Angeles, with the best available information on the hazards that are within their jurisdiction so they can mitigate the hazards to build the best communities.
“They don’t want to subject the community to hazards that would destroy a community,” Parrish said, adding that the final decision is best left to the entities that have land-use position-making authority.
If a municipality knowingly constructs a building that is within a fault zone, the local community then bears the liability for any damage caused, he said. Before the act, the developers would have been held accountable for any damages, Parrish said.
“This act requires the lead agencies to command the developer to do an investigation of the site if it’s within an Alquist-Priolo zone. If it’s not, it’s all on the developer’s head,” he said, adding that the state can’t really intervene.
If local officials determine that the zone doesn’t apply to a particular development, it would be up to the community to challenge local legislators, Parrish said.
He said the Alquist-Priolo zone will likely encompass the Millennium site and the future site of BVLD6200, a development at Hollywood Boulevard and Argyle Avenue that reportedly did not receive a seismic evaluation. Parrish said geological survey staffers believe BLVD6200 is near is a splay (a branch) of the Hollywood Fault.
“I think it’s pretty safe to say that that building will also be in the new Alquist-Priolo zone,” he said. “It’s pretty likely that whole area is going to be in a Alquist-Priolo zone.”
Parrish said the Hollywood Fault has been mapped, but the state has never placed a zone around the fault. He said the city was “very proactive” and placed its own zone around the fault in past. Since the agency has “little to no money” for the zoning program, staff members did not want to duplicate work that a local agency was already doing, Parrish said.
Since then, an “awful lot” of research and investigation has been conducted since the city put the zone in, and it needs to be adjusted, he said. Parrish said the city’s zone had not been updated for “many, many” years.
Luke Zamperini, of the city’s Department of Building and Safety, said the city has not created an earthquake zone in the area. He said Alquist-Priolo zones are only effective when completed by the state geologist.
“The city does not have an earthquake study zone at all, at least not yet,” Zamperini said.
He said the city is waiting on the Millennium developers to conduct more extensive exploration, although it appears Millennium Partners and Argent Ventures are waiting to trench the area until legal matters are handled. The developers are being sued by a coalition of community groups and representatives of the W Hotel.
“Trenching is a big deal, and it’s unusual,” Zamperini said. “But it’s good way to determine if there’s anything there or not.”
Hypothetically, if there is no fault trace under the footprint of the proposed project, then the developers can proceed as planned; if a fault trace is identified, they’ll be required to move the structure, he said. Zamperini added that a geotechnical company hired by the developers will do the trenching, and the company will then write a report that will be turned over to the department.
As for the Alquist-Priolo zone’s effect on development in Hollywood, he said he doesn’t believe it will have a large impact. Zamperini said a mapped zone would give the city “real, definitive” boundaries in which to work.
“We’ve always known that there’s probably earthquake faulting in that general area because we have a plane intersecting a mountainous area,” he said. “That’s usually a pretty good indicator.”
Any development within the zone would be required to complete a surface rupture study, Zamperini said.
Parrish said another large earthquake is likely for the area in the next 30 years, but what fault that will occur on is unknown. He referenced a Uniform California Earthquake Rupture Forecast statistic.
“Generally, it says that there is about a sixty-five percent chance in the next thirty years of another Northridge earthquake in Los Angeles,” Parrish said, adding that Northridge quake was measured at 6.7 on the Richter scale.
He said the agency would release the preliminary Alquist-Priolo maps in the near future. By law, the California Geological Survey must allow lead agencies and the public to review the maps and provide additional comments or information. Parrish said the state’s Mining & Geology Board would review the comments and determine if any changes are necessary.
“Whatever that outcome is, we’ll then publish the final map,” he added.
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