January 2025 Wildfire in Los Angeles County and Water Supply Reliability – What Happened and What Can We Learn
Los Angeles County 2025 Wildfires and Water – We Can Do Better
Mark Grey, Ph.D., Director of Environmental Affairs, Building Industry Association of Southern California
Article originally published at: https://issuu.com/biasc/docs/bia_online_magazine_-_february_2025
Wildfire erupted in early January across several densely populated sections of Los Angeles county, causing widespread devastation and the tragic loss of lives and property at a scale and speed rarely seen in southern California. For many days on end with no let-up, high winds and smoke prevented airborne chemical and water drops typically employed to fight wildfire encroaching on urban areas, making the situation even worse once the fires hit homes, businesses and commercial centers. By the time local firefighting resources were deployed at communities and neighborhoods, it was too late to protect structures and property with water, given the magnitude of the wildfires.
We now know from fire disaster relief experts that many factors mixed to create the wildfire’s destructive force and geographical extent: extreme dry conditions all over the county, unusually fierce and days-long sustained Santa Ana winds, vulnerable electrical transmission infrastructure near the wildland-urban interface, and aging water storage and distribution systems, many of which lacked back-up electrical power to drive pumps.
Of these factors, I want to focus here on water storage and delivery: What went wrong and right? What we can learn from the response in Los Angeles county and elsewhere in California after wildfire? And what are we doing as homebuilders to better safeguard our homes, businesses, and communities in the future and mitigate water supply and delivery-related uncertainties here in southern California?
I must first briefly address the abundance of water-related misinformation and confusion spread across the media about the lack of water for firefighting in the days and weeks after the wildfires. Some reports contained kernels of truth, but most were debunked after close examination by fire forensics and water management experts called into investigate in the fires aftermath.
As the wildfire raged and destroyed property and lives, it became quickly apparent that the amount of water necessary to firefight simply was not available, primarily because urban water reservoir storage and hydrant distribution and pumping systems are not designed to fight wildfires of this size and ferocity. But problems arose beyond supply challenges.
Reservoirs ran low and in some instances, water pumps didn’t work because of no power. This reduces hydrant water flow and in some reported cases it was cut off completely. Making matters worse, at least one local large water storage reservoir near the Pacific Palisades – Malibu area in densely populated northwestern Los Angeles County was off-line and undergoing repairs. This caused CalFire and other assisting agencies to move air resources to more distant outlying areas for supplying water-drop aircraft, increasing response time and hindering fire fighters front-line efforts when they needed help the most.
As mentioned, residential hydrant systems in urban areas are not designed to fight wildfire. They’re designed to handle one or two structure fires, not hundreds burning at the same time. As we know from recent history in California, this is not the first time hydrants ran dry in a major firefight. Similar water pressure problems occurred during the 1991 Oakland Hills Fire, which destroyed more than 3,000 homes, and two Ventura County fires that each burned more than 1,000 homes in 2017 and 2018.
Ultimately then, in a few populated centers in Los Angeles County firefighting water demand could not match the wildfire’s intensity, with aging and undersized water infrastructure cited as contributing factors. Multiple experts across the water management spectrum made this observation and tried to reassure the public California municipal fire code is designed to handle multiple building fires, but not rampant wildfire, and that system modernization to handle ever larger wildfires must be done now.
What then, does water system modernization for firefighting include? There are three main elements often cited: increasing firefighting water supply storage, upgrading local water distribution infrastructure, and improving electrical system reliability and emergency preparedness. Take for example my own home town water distributor, Yorba Linda Water District, who was just highlighted in a CNBC news article for its efforts to better fight wildfire after a devastating 2008 fire that destroyed more than 200 homes.
The District added backup generators at water pump stations that had failed during the 2008 fire, added a long-planned underground reservoir, and installed a first-of-its-kind water tank called a Heli-Hydrant. The underground tank allows helicopters to land over the top of it and quickly fill with water and leave, and its protected from fire. Just north of Los Angeles county, Carpinteria Valley Water District, in the aftermath of the wind-driven devastating 2017 Thomas Fire, took systemwide measures to bolster its firefighting response infrastructure: more storage, new back-up power upgrades, and an emergency supply intertie agreement with a neighboring water agency.
At the construction level, our BIASC members tell me California enforces one of the strictest fire prevention building codes in the nation. Homes built today are using the very latest materials innovations to prevent fire from ever starting and we’re using smarter project layouts and designs. For example, on a home’s exterior, required roof and eave protections minimize ember intrusion and radiant heat fire transmission. Outside the home envelope, defensible spaces are combined with use of concrete or stucco walls and screens and use of appropriate plant materials. A related benefit: all these measures combine to reduce reliance on water, creating a more resilient fire-safe community.
While we know very well from experience that older homes such as those ravaged in the recent Los Angeles county fires do not perform well, we are encouraged that our planned communities built since 2010 (when the fire code changed) perform substantially better due to the required protections. Going forward our continued vigilance in paying attention to preventative fire safety will pay off.
