A recent controversy at LA’s mixed-use Millennium Hollywood development has focused eyes on a topic not usually considered sexy: earthquake zoning. After recently gaining city council approval, Millennium Hollywood’s developers have been asked to trench their site to ensure that it does not sit astride the Hollywood Fault, a location that could jeopardize its feasibility. (A company spokesperson told AN that this plan was always in the works). The results are still forthcoming.
AN talked to California State Geologist John Parish—chief administrator of the California Geological Survey—about Millennium Hollywood, the successes and challenges of earthquake zoning in the region, and just how much of the state’s development lies on precarious ground. Parish, who provides geological expertise to the government and several state agencies, has held his position since 2005.
The Architect’s Newspaper: What is your involvement with Millennium Hollywood?
John Parish: Under the Alquist-Priolo fault zoning act (which was passed in 1971 after a particularly destructive earthquake that destroyed several buildings) we are mandated to zone active surface faults in the state. The Hollywood fault was on our list coming up at the beginning of 2014. Our office in LA was reading the papers and saw that this project appeared to lie on or near the Hollywood fault. This was just before the LA city council was going to vote on it. We sent a letter to city council saying that we were going to do a survey in the next few months and that we might be able to help. We were going to do it anyway and we upped our schedule by six to eight months to provide them with more information. We won’t be doing the trenching. The [developer] will do the site investigation.
Do projects always need to trench to see if they’re on or near a fault?
Any time we zone an active surface fault it’s a state law that it becomes a mandatory zone of investigation. We have placed zones around 5,000 surface miles in the state in 30 counties and 105 cities. We are still in the process of doing that. So if a developer decides to develop he looks at the planning department’s maps and they will indicate where the zones are. Then the proponent has to do a study.
Structures meant for human occupancy cannot be built atop the surface traits of an active fault. If you can’t prove the absence of fault traces, you must be 50 feet from any known trace.
Millennium Hollywood is a case where the city had zoned the area 25 years ago. It was coming on our radar because it hadn’t been looked at for some time. We will soon zone the area around the Hollywood fault. It’s highly likely that the Millennium project will lie within the mandatory zone of investigation for the Hollywood fault.
How does a developer know if their project is on a fault?
A developer can find it on a California fault activity map. That’s on our web site and it’s also in hard copy. It’s a statewide map. If you’re anywhere near these active faults it’s prudent to take a look to do a study there.
Is your fault map up to date?
It’s very up to date. We’ve mapped over 15,000 surface faults throughout California. There are about 5,000 miles that we deem active. They’re all over the state. We’re the most seismically active zone in the country.
It seems like much of that is in urban areas?
I put it to people that we’ve got the largest population of any state, 38 million people. And we’ve put 25 million of those people on top of the shakiest ground in the United States. It’s very important that we get these zones out there and that people be aware of them as they’re building.
What has held up your earthquake zoning?
The zoning is continuously being done. We have a notoriously poorly funded state mandate, but we work on these as fast as we can. The zoning has been held up by a lack of funding. Otherwise we would have had the Hollywood fault zoned years ago.
Will this information be a stumbling block to development?
It’s not meant to be a stumbling block. Most faults in LA are sub-surface, meaning a lot of ground will be shaking. What the law is concerned with is only those straddling the surface rupture of a fault. It’s not meant to deter development. It’s meant to help in the wise planning of development so those developments will be safe in the long term, and so that we don’t have any nightmares.
Does Hollywood development seem particularly at risk?
There are undoubtedly buildings there that straddle the fault. Most were built prior to the zoning act. When it comes time to refurbish them, if the refurbishment costs more than 50 percent of the cost of the structure, then it must be torn down. In the long term the act is meant to clear buildings off of active surface zones. No one can push them out. They don’t have to do anything until it’s time to do a renovation.
Are there major buildings currently sitting on fault lines?
I wouldn’t be surprised if there are. We won’t know until we put the zoning down. Even if there are no major buildings there are certainly a lot of buildings.
What faults have you zoned in Los Angeles?
We’ve zoned the Newport-Inglewood Fault Zone and the Raymond Fault zone. A great deal of LA has been done. What is left to be done are the Santa Monica Fault and the Hollywood Fault. Building owners can do a detailed fault study of the location of their building and find out if they can renovate. If their building is on top of one of the surface splays then they’ll have to do a lot of rethinking.
Once we get the zoning finished then a developer can pretty well guess how many buildings there are within the zone. The only way to know for sure is if there are trenches dug to see if they are sitting on one of those traces.
Is trenching costly?
It’s not terribly costly, no. In relation to the investment made it’s a small amount. It depends where the trench is, and how much would need to be torn up. I’d say from $50,000 to $100,000.
When will the zoning of Los Angeles be done?
Depending on the budgets, I’m guessing it will be done in five or six years. There is no direct fund for the Alquist-Priolo Act. The state’s been in a fiscal bind for some time. We’re always looking for new ways to fund that. We keep trying.
Are there examples of developers not being aware of faults under their buildings?
Most of the time people follow seismic issues very well. Local planning departments have our maps at their offices. They always check their locations in the context of the zones. They’ve been very good at that. Lots of developers know what they’re getting into.
How is enforcement carried out?
There’s no state enforcement. It’s a state law but it’s enforced at the local jurisdictions.
What else should owners of buildings know?
There’s an awful lot of literature. Other than checking with the planning department, checking with local universities and hiring geological consultants might save them an awful lot of regret. We haven’t got all the faults mapped and a lot of local consultants have information that might be beneficial. In California that’s the prudent thing to do. This ain’t Kansas.