As wildfires swept through the canyons of Pacific Palisades, firefighters fought a desperate battle to save homes and lives.

Seventeen miles east of downtown Los Angeles, dozens of officials at the Los Angeles Department of Water and Power Emergency Operations Center huddled around computers around a long conference room table. The screen displays system water pressure from remote sensors located throughout the city.

As more firefighters rushed to put out the blaze on the afternoon of Jan. 7, it became increasingly clear that the Palisade needed more water, and fast.

In the tanks that regulate pressure upstream of the canyon, the amount of water begins to decrease. DWP officials must figure out how to increase pressure in the western portion of the grid, where a 36-inch pipe carries water from the Bellaire Reservoir and then winds uphill into the Palisades Highlands.

They face a high-stakes choice: shut off water to nearby communities like Brentwood, or face declining water pressure on the front lines.

Without water, dialysis centers and other medical facilities suffer. How long does it take to safely close the valve? Can the pipeline withstand such a shift, or will it burst?

As the fire spread, flames reached some areas where water shutoffs were being considered.

DWP officials ultimately decided that shutting off water supplies to neighboring areas would endanger those communities and undermine efforts to fight the spread of the fires, DWP Water Division Chief Anselmo Collins said in his first interview about the utility's handling of the water. effort. flow to fight devastating wildfires.

"We had a plan, but we didn't execute the plan," Collins said, because those neighboring enclaves "need water for fire protection."

DWP's decisions, both in the years leading up to the Palisades fire and in the hours following the explosion, drew harsh criticism, prompting Gov. Gavin Newsom to order an investigation. On Tuesday, the Los Angeles City Council voted unanimously to require the DWP to publicly analyze its actions during the Palisades fire.

Water officials and experts interviewed by The Times said municipal water systems in Los Angeles and elsewhere, even in areas with higher wildfire risks, are often not designed to fight fire storms that ravage entire communities. Collins' speech detailed for the first time the DWP's response to the most devastating fire in Los Angeles history.

Firefighters had to contend with dry hydrants as the fire spread rapidly in high winds and pressure plummeted due to heavy water use at high altitudes. Another complication: less water available because the 117-million-gallon Santa Ynez Reservoir upstream from the Palisade will be drained for maintenance in February 2024.

Collins said water quality regulations required the reservoir to be emptied due to a broken cap. Repairs costing about $130,000 by the contractor have not yet been completed, and Collins does not expect the reservoir to be restored to use until April or May. Collins said the DWP was still trying to determine the impact of the reservoir closure.

“I think it will help, but I can’t tell you how much that will help right now,” Collins said.

Asked what he would do differently, Collins said it was too early to say. He said he and his colleagues will assess the overall response later.

"I'm focused on restoring the system right now. That's the No. 1 priority," he said.

Los Angeles residents get their water from a grid of pipes that crisscross the city.

In the Palisades, homes scattered across a sloping canyon landscape draw water from cisterns on the hillside.

A 36-inch pipe along Sunset Boulevard carries water to Brentwood and Palisades Village, then winds up to elevation along Palisades Drive Hundreds of feet in the Highland community. There, the water is pumped to three tanks on the mountain, each with a capacity of 1 million gallons.

These tanks are located high in the community and maintain water pressure to the homes and fire hydrants below. When someone takes a shower, fills a pool, or turns on a fire hydrant, gravity pulls water down from the tank.

During a typical day, more water is pumped from the pipes to refill the tank, counteracting each shower or glass of water.

Inside the DWP's modernist headquarters on Tuesday, Collins and his colleagues watched as water levels were getting so low that pumps were unable to refill tanks faster than water could be siphoned to fire hydrants and homes below.

Just before 5 p.m., the first person to fail with the system was Marquez Knolls, a tank hidden in a cul-de-sac north of Palisades Village.

“When the tanks were emptied, we realized the need was so great,” Collins said.

The DWP sent a team to the nearby area in the hope of installing a device that would regulate pressure at and below the site. But as crews began working, fire engulfed the home next door.

"The fire department immediately told the firefighters they had to leave for their own safety," Collins said. "They were surrounded by fire."

Collins defended the DWP's decision. He said employees were on "high alert" and ready to report to shipyards across the city in the event of an emergency.

"You don't know what the emergency is going to be, and you don't want to make assumptions and put your people in the wrong position," he said.

By 2:30 p.m., water levels in the next-highest water tank trailer at Mediterranean Mini Mansion in Palisades Heights began plummeting, Collins said. By 8:30 p.m., the tank was dry. As night falls, pressure drops in dozens of fire hydrants.

The fence system quickly became like a hose that had been pierced a thousand times and its flow rate was severely reduced. Dozens of firefighters were pumping water from hydrants as more homes burned. As buildings collapse and pipes melt or buckle, water can gush out, further reducing pressure.

“Especially when you lose a lot of housing, the system starts to drain,” said water consultant Tom Kennedy, former general manager of San Diego County’s Rainbow Municipal Water District. “As a result, maintaining system pressure and volume in the tank is very difficult.”

At one point, the DWP called in a water tanker to refill the fire truck directly. Nine tankers arrived on Tuesday, followed by six more the next day, each carrying 52,000 gallons. The state sent more tankers.

Around 6:30 p.m. Tuesday, water levels in the region's highest tank, a squat steel tank in Temescal Canyon, began to drop. At 3 a.m. Wednesday, the water tank was empty.

"The fire department uses dozens of hydrants," Collins said. "Even though we were pumping water into the tank, the tank level was still falling."

Meanwhile, Collins and his team diverted as much water as possible, quadrupling the normal flow rate to nearly 45,000 gallons per minute, enough to fill an Olympic-sized swimming pool every 15 minutes.

Kennedy, a former San Diego County water official, agreed with the DWP's decision not to shut off water to nearby communities.

"If they shut off the water to other areas, I think there's a good chance that some other areas could have localized fires that could turn into large fires," Kennedy said. During one blaze, firefighters put out flying embers in surrounding neighborhoods, he said. Limit the spread.

By 9 p.m., with wind gusts as high as 90 mph, helicopters were grounded and unable to pump water from reservoirs in Bel Air, Encino and Hollywood that are the backbone of the city's strategy to combat wildfires.

The DWP currently estimates that 20 percent of Palisades' nearly 1,100 fire hydrants have lost pressure, a number Collins said is based on the number of homes at higher elevations served by three water tanks. The remainder, he claimed, was subject to pressure from the water mains.

Elsewhere in Southern California, vast amounts of water are stored in reservoirs and underground, which Los Angeles can use when needed. But transferring water from those locations requires coordination between the city and the Southern California Metropolitan Water District, the region’s water wholesaler.

As the Palisades Fire intensified and DWP asked MWD for help, water was quickly flowing through a backup connection near the intersection of Sunset Boulevard and the 405 Freeway that had not been used since 2019.

“There are a lot of things we want to try,” said Deven Upadhyay, MWD interim general manager. Over the next 48 hours, the agency activated a water pumping plant next to the Hollywood Burbank Airport and asked state officials to halt maintenance on the Castaic Lake reservoir to increase the flow of water to the West Side, Upadhyay said.

The fire has spread to 23,713 acres and nine people have been confirmed dead. Aerial mapping shows about 5,000 structures were damaged or destroyed in the Palisades Fire, and officials have so far confirmed 2,869 structures were destroyed and 508 structures were damaged.

Collins and other DWP officials emphasized that their current focus is on restoring the Palisades water system.

Hundreds of DWP workers fanned out across the burn area over the weekend, visiting destroyed homes and businesses.

By Tuesday morning, water supplies had been shut off at more than 4,700 locations, allowing DWP crews to refill water tanks and restore pressure. By Wednesday evening, the Marquez Knolls and trailer tanks were completely filled.

MWD official Uphadayay said it will take time to analyze what caused the drop in water pressure and how to prevent it from happening again. He echoed comments from other water managers that the design of urban water systems poses "significant challenges" to large-scale firefighting mobilization.

Collins said he's willing to overhaul the system to deal with "climate extremes," but DWP's customers — Los Angeles residents and businesses — would have to be willing to pay for it.