Water systems aren’t designed for unlimited demands during wildland-urban interface fires.
by Kylie Mohr, High Country News
When wind-driven embers sent flames ripping through the Los Angeles area on Jan. 7, firefighters and residents began noticing less water pressure in their hoses. In some cases, fire hydrants had no water at all.
The trouble started hours after the fire did. The first water-storage tank supplying firefighters ran out of water at 4:45 p.m. By 8:30 p.m., so did the second tank. And at 3 a.m. the next morning, the third gave out. Pacific Palisades relies on a series of storage tanks in the hills: Water is pumped up to the tanks, and then gravity sends it flowing downhill to maintain the pressure in the hydrants.
At a press conference on Jan. 8, Janisse Quiñones, Los Angeles Department of Water and Power CEO and chief engineer, said water use peaked at four times the usual rate, decreasing water pressure during the first 15 hours crews fought the Palisades Fire.
“We are fighting a wildfire with urban water systems,” she said. The water pressure problem caused 20% of fire hydrants in use for the Palisades Fire to go dry, according to L.A. Mayor Karen Bass. Low water pressure also occurred in Pasadena and Altadena, which are served by different utilities. On Friday afternoon, California Gov. Gavin Newsom called for an independent investigation into the problem and the availability of water supplies.
But water is only one piece of an extremely complex equation that includes flammable chaparral shrubs, dry conditions worsened by climate change, and dense communities located in fire-prone areas. It’s unlikely that extra water would have significantly reduced the destruction, since there’s only so much firefighters can safely do in 100 mph wind gusts and bone-dry humidity. Altogether, at least 12,000 structures were lost in the Palisades and Eaton fires.
“I’ll be clear: We could have had much more water. With those wind gusts, we were not stopping that fire,” Pasadena Fire Chief Chad Augustin said in a press conference on Jan. 8.
“I’ll be clear: We could have had much more water. With those wind gusts, we were not stopping that fire.”
The same gusty Santa Ana winds that fanned the flames hampered firefighting efforts, temporarily grounding planes and helicopters that would have normally raced to drop water and fire retardant during the first 24 hours.
The lack of water availability and loss of water pressure raise questions about how — and whether — Western communities are prepared for life in a world where wildfires are becoming more extreme, more frequent and moving faster than ever, all factors that threaten the capacity of existing infrastructure.

Experts say that with most wildland-urban interface fires burning through homes and structures as well as flammable vegetation, the water system’s ability to get supplies where they need to go is sorely tested — even if nearby reservoirs are full or close to it. (The Los Angeles Times reported that an additional key reservoir in Pacific Palisades was empty for maintenance.) “This isn’t uncommon,” said Michael Gollner, director of the UC Berkeley Fire Research Lab. “It’s just an incredibly challenging situation at the scale and number of structures involved at the same time.”
Water begins leaking out of pipes and water pipes burst open when homes burn to the ground. When homeowners leave sprinklers on to protect their property, water is also sucked from the system. Pumping stations sometimes lose power, and then too much pressure is placed on too many hydrants while firefighters do their best to put out spot fires and keep embers from spreading. All this leads to a loss of water pressure.
Urban water systems are designed to protect a few houses or an apartment complex from fire — not block after block of an entire neighborhood, with everything burning at once. According to the National Fire Protection Association, the amount of water required during a fire is calculated “based on a single building with additions for potential spread to adjacent exposures, but not for multiple buildings fully involved or for approaching wildfires.”
Urban water systems are typically designed to have 25% to 40% more water than needed to prepare for homes that catch on fire, said Greg Pierce, director of the UCLA Water Resource Group.
“But they’re going to run out of water pretty quickly in a wildfire event, much less a wildfire event of this nature,” Pierce said. Investing in the amount of infrastructure — all the hydrants, tanks, pipes and other improvements necessary to substantially increase water flow for fires this intense — would be “incredibly expensive,” Pierce added.
Water systems that have low pressure or temporarily lack any water at all during an intense urban conflagration are not unique to Pacific Palisades or Altadena. “By all accounts, I don’t really know a water system anywhere that could have actually stopped the fire,” Pierce said. Louisville, Colorado, experienced low to no pressure in some of its fire hydrants during the destructive Marshall Fire in 2021, and firefighters have struggled with hydrants in Malibu in the past.
“By all accounts, I don’t really know a water system anywhere that could have actually stopped the fire.”
Water systems are also vulnerable to long-term impacts following wildfires. A loss of water pressure can allow contaminants from burned plastic pipes to leak into the system, including volatile organic compounds that are harmful to human health. Gollner described all the chemicals that can burn in a house fire as “a whole chicken soup of dangerous and carcinogenic compounds.”
While the scope of potential water contamination in Los Angeles is still unknown, as of Jan. 13, residents of Altadena, Pacific Palisades and parts of Pasadena were told by numerous utilities not to drink tap water until further notice owing to the possible presence of ash, soot and other chemicals. Drinking water systems have been damaged in wildfires in communities from Hawaii to Colorado. After fires contaminated the water systems in both Paradise and Santa Rosa, California, miles of pipes needed repair or replacement.
Given the fiery future the West is facing, Gollner suggested thinking beyond water availability to also consider techniques that can reduce wildfire risk, such as clearing defensible space of flammable plants and spacing structures farther apart when possible.
“I really think the solution is not to say, ‘Can we get more and more water?’” Gollner said. “The solution is, can we not have so many homes igniting at once? We have to change things on the ground before the fire.”
This article first appeared on High Country News and is republished here under a Creative Commons license.