LA County crews pulled nearly 148,000 cubic yards of sediment from Eaton Wash Dam in one week, racing to restore the Pasadena reservoir before El Niño storms arrive.
The county removed the sediment between Sept. 22 and Sept. 28, first reported by the Pasadena Star News. Excavators scooped dirt and debris into trucks that hauled the material to empty mining pits in Irwindale. The goal is to bring Eaton Wash Dam back to its full capacity of about 956 acre-feet.
Sterling Klippel, assistant deputy director for the Los Angeles County Department of Public Works, said the target is Oct. 15, the official start of the rainy season.
"When you have burn scars, that significantly increases the amount of rocks, boulders, sand and mud that washes down …" Klippel said.
The dam sits across the street from canyons the Eaton fire raced through in January 2025. Both Eaton Wash Dam and Devil's Gate Dam in Pasadena draw water and sediment from the 700,000-acre Angeles National Forest watershed. The county also aims to finish cleanouts at Devil's Gate and San Gabriel Dam by the same date.
A wetter winter ahead
NOAA's Climate Prediction Center placed a greater than 90% chance of a very strong El Niño this fall and winter in its Sept. 17 update. The agency estimated a 75% chance the event could exceed every El Niño since 1950. Seasonal outlooks show above-normal precipitation probabilities of 50% to 60% for coastal California from December through March.
LA County Public Works Director Mark Pestrella told the Board of Supervisors on Tuesday, Sept. 1 that the county is placing "significant attention on Altadena," citing concern about rain moving rocks and sediment from fire-blackened hills. He said 600 Public Works employees would be on 24/7 standby through April, the Pasadena Star News reported.
A separate $9.99 million contract with Sully-Miller Contracting Co. targets 190,000 cubic yards of sediment from Eaton Wash Dam, with completion expected in November, according to a Sept. 14 Board of Supervisors agenda report.
Pasadena watches Hastings Ranch
The City of Pasadena has placed eight to 10 homes in Upper Hastings Ranch on a watch list for possible mud and debris flows. Emergency Services Manager Nallely Procopio told the Municipal Services Committee on Wednesday, Sept. 23 that officials identified properties where a debris flow could threaten safety or block access, Pasadena Now reported.
Pasadena Public Works Director Greg De Vink said Upper Hastings Ranch is the only area where the city has seen recurring, significant mudflows. He recommended sandbags, which the city provides free.
Procopio said Pasadena can now issue emergency alerts directly, without relying solely on the county. Wireless evacuation warnings can reach phones in an affected area without registration, but residents must sign up separately for the city's additional local alert service.
Rebuilding in the path
The Eaton fire destroyed or damaged about 9,500 structures, including 6,746 residential units. As of Wednesday, Sept. 30, about 213 homes had been completed, 2,310 were under construction and 4,012 building plans had been approved.
Victoria Knapp, a former Altadena Town Council member who lost her home in the fire, said her rebuilt house is 85% finished with a metal roof in place. She hopes to move in around early November. During construction last year, builders had to pump water off the property after rains.
Knapp said she worries torrential rain could damage new concrete foundations or collapse dirt footings at other rebuild sites. Most builders are expected to continue work despite the forecast, perhaps covering wood framing with plastic sheeting.
What residents should know
Virginia Kimball, who headed a disaster preparedness center after the 1993 Kinneloa fire near the same foothills, warned that debris flows can strike suddenly in areas burned within the past three to five years. They can kill.
LA County residents in recent burn areas can call (800) 933-0930 for free engineering advice or visit ready.lacounty.gov/rain for rain-prep guidance, according to LAist. Pasadena residents can call 311 during prolonged storms to reach the appropriate city department.
