About eight to 10 homes in Upper Hastings Ranch are on Pasadena’s watch list for possible mud and debris flows this winter as the city prepares for storms associated with El Niño.
Emergency Services Manager Nallely Procopio told the Municipal Services Committee Tuesday that officials have identified properties where a debris flow could threaten residents’ safety or block access. City personnel visited vulnerable households during storms last year and plan to notify them again when forecasts warrant it.
“A lot of it right now is potential,” Procopio said. She said significant storms generally come into focus seven to 10 days ahead, giving the city time to prepare and contact residents.
The risk is heightened in foothill areas affected by the Eaton Fire, Procopio said.
The weather pattern occurs when surface waters in the central and eastern tropical Pacific Ocean become warmer than usual.
That extra heat changes winds and atmospheric circulation, influencing weather around the world. In Southern California, El Niño increases the likelihood of a wetter winter and strong storms.
The National Oceanic and Atmospheric Administration’s Climate Prediction Center said last month in its diagnostic discussion there is a 69% chance the October-December season will exceed every El Niño on record dating to 1950.
The city has joined weekly National Weather Service calls focused on El Niño and is coordinating with Los Angeles County and neighboring communities.
Public Works Director Greg De Vink said Upper Hastings Ranch is the only area where the city has seen recurring, significant mudflows. Mud has come through residents’ backyards and driveways and into the road, making barriers impractical for some homes.
“The K-rail, I don’t think would really do much to stop it,” De Vink said. He recommended sandbags, which the city provides free.
“The sandbags are effective,” he said. “It’s kind of laborious to put them out there, but they’re just as effective.”
De Vink said crews will also inspect catch basins, clear storm drains in areas prone to backups and keep barriers in place along New York Drive, where the city has had concerns about landslides since the fire.
Pasadena Water and Power officials said they are increasing inspections of electrical equipment and burned hillsides near water facilities. The utility is preparing crews and supplies for outages and taking steps to protect its Arroyo Seco spreading grounds while keeping the basins available to capture stormwater.
Officials cautioned that El Niño does not guarantee heavy rainfall. A water department official told the committee that past strong El Niño periods in Southern California have produced conditions ranging from extremely wet to extremely dry.
Councilmember Tyron Hampton asked where residents should call during a prolonged storm. Pasadena Water and Power General Manager David Reyes said 311 would connect callers with the appropriate city department.
“I do think that the public should understand and know that the 311 number will get you all the information that you need in the event of emergency,” Reyes said.
Procopio said Pasadena can now issue emergency alerts directly, rather than relying solely on the county. Wireless evacuation warnings and orders can reach phones in an affected area without registration. Residents must sign up separately for the city’s additional local alert service.
City officials urged residents to learn their evacuation zones and prepare supplies for at least 72 hours.
Get our daily Pasadena newspaper in your email box. Free.
Get all the latest Pasadena news, more than 10 fresh stories daily, 7 days a week at 7 a.m.
