L.A. County Calls for Flood Control Improvements

Recently revealed estimates put far more people in the region at risk for catastrophic flooding than previously thought.

2 minute read

December 8, 2022, 11:00 AM PST

By Diana Ionescu @aworkoffiction


Aerial view of San Gabriel River where it meets the ocean in Long Beach, California

The mouth of the San Gabriel River in Long Beach, California. | trekandshoot / San Gabriel River

The Los Angeles County Board of Supervisors wants to know how to shore up the region’s flood control infrastructure as experts predict “an increase in epic downpours” that could pose significant flood risk to many L.A. communities. Louis Sahagún reports on the story for the Los Angeles Times.

The supervisors are calling for a report from the Department of Public Works (DPW) detailing the state of existing infrastructure and plans for improving it. The motion comes in response to a recent study that highlighted the disproportionate risk faced by low-income communities of color. “The study’s unprecedented combination of high-resolution flood modeling and socioeconomic data indicates that major floods would occur between the Dominguez Channel on the west and the Los Angeles River on the east,” Sahagún writes, noting that the analysis put roughly 874,000 people and as much as $108 billion in property at risk for catastrophic flooding.

“Until recently, it was thought that a flood event of that magnitude was likely to occur every 1,000 to 10,000 years. New research, however, suggests that the chances of seeing another one of that scale over the next 40 years are about 50/50.” This makes the urgency of upgrading flood control and mitigation infrastructure more severe than previously thought. According to Mark Pestrella, director and chief engineer of the Los Angeles County Flood Control District, “The Board’s action today aligns with the county’s sustainable plan to make infrastructure improvements that reduce flood risk, increase local water supplies through stormwater capture and groundwater recharge, and improve water quality across the county.”

Tuesday, December 6, 2022 in Los Angeles Times

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

Cover CM Credits, Earn Certificates, Push Your Career Forward

Aerial view of town of Wailuku in Maui, Hawaii with mountains in background against cloudy sunset sky.

Maui's Vacation Rental Debate Turns Ugly

Verbal attacks, misinformation campaigns and fistfights plague a high-stakes debate to convert thousands of vacation rentals into long-term housing.

July 1, 2025 - Honolulu Civil Beat

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.

July 9, 2025 - Diana Ionescu

Map of Haussmann's redesign of Paris in the 1850s through 1870s under Napoleon III.

In Urban Planning, AI Prompting Could be the New Design Thinking

Creativity has long been key to great urban design. What if we see AI as our new creative partner?

June 30, 2025 - Tom Sanchez

View of dense apartment buildings on Seattle waterfront with high-rise buildings in background.

King County Supportive Housing Program Offers Hope for Unhoused Residents

The county is taking a ‘Housing First’ approach that prioritizes getting people into housing, then offering wraparound supportive services.

July 11 - Real Change

Aerial view of suburban housing near Las Vegas, Nevada.

Researchers Use AI to Get Clearer Picture of US Housing

Analysts are using artificial intelligence to supercharge their research by allowing them to comb through data faster. Though these AI tools can be error prone, they save time and housing researchers are optimistic about the future.

July 11 - Shelterforce Magazine

Green bike share bikes parked in a row on a commercial street with outdoor dining and greenery.

Making Shared Micromobility More Inclusive

Cities and shared mobility system operators can do more to include people with disabilities in planning and operations, per a new report.

July 11 - Cities Today