Los Angeles Mandates Fault Surveys in Risky Areas

According to a new rule, developers building over known faults will need to drill or take samples to find the rift's exact position. While it slows down construction, the measure might prevent catastrophic future quake damage.

1 minute read

August 7, 2015, 11:00 AM PDT

By Philip Rojc @PhilipRojc


Los Angeles Skyline

Ben+Sam / Flickr

Drought resilience may be a hot topic these days in Southern California, but that doesn't mean an old threat has vanished. A new rule in Los Angeles stipulates that "developers looking to build a new structure in [earthquake risk] spots must first prove they won't be doing so on top of a dangerous fault, according to Ashley Atkinson with Mayor Eric Garcetti's Office."

The rule only applies to faults already mapped by the California Geological Survey. However, "the state doesn't have the funds it would need to map every potentially dangerous fault, leaving a number of well-known faults unmapped, including several in Los Angeles."

This safety measure may put a damper on some projects, but shouldn't prove too difficult a hurdle. From the article: "The new rules will likely slow down some future projects since digging to look for a fault — or 'trenching' as it's known — is time-consuming and can cost tens of thousands of dollars. However, some developers might be able to provide enough evidence by drilling for core samples, Atkinson explained, which is a less involved process."

Friday, July 17, 2015 in KPCC

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Use Code 25for25 at checkout for 25% off an annual plan!

Redlining map of Oakland and Berkeley.

Rethinking Redlining

For decades we have blamed 100-year-old maps for the patterns of spatial racial inequity that persist in American cities today. An esteemed researcher says: we’ve got it all wrong.

May 15, 2025 - Alan Mallach

Logo for Planetizen Federal Action Tracker with black and white image of U.S. Capitol with water ripple overlay.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

May 14, 2025 - Diana Ionescu

Front of Walmart store with sign.

Walmart Announces Nationwide EV Charging Network

The company plans to install electric car chargers at most of its stores by 2030.

May 7, 2025 - Inc.

Aerial view of Albuquerque, New Mexico at sunset.

New State Study Suggests Homelessness Far Undercounted in New Mexico

An analysis of hospital visit records provided a more accurate count than the annual point-in-time count used by most agencies.

May 16 - Source NM

Close-up on white bike helmet lying on pavement with blurred red bike on its side in background abd black car visible behind it.

Michigan Bills Would Stiffen Penalties for Deadly Crashes

Proposed state legislation would close a ‘legal gap’ that lets drivers who kill get away with few repercussions.

May 16 - Wood TV 8

Muni bus on red painted bus-only lane in downtown San Francisco, California.

Report: Bus Ridership Back to 86 Percent of Pre-Covid Levels

Transit ridership around the country was up by 85 percent in all modes in 2024.

May 16 - Mass Transit