On Thursday evening, February 13, 2025 at approximately 5:02 PM, a torrential downpour struck the fully burned-out Eaton Canyon area. Rain rates of up to 2.04″ per hour were observed by weather station data at the Eaton Reservoir as a rigorous narrow cold-frontal rainband (NCFR) pushed through the Los Angeles Basin. Approximately 22 minutes later at 5:24 PM, a ~12-foot tall, 100-foot wide surge of water and debris emerged from the mountain gorge and entered Eaton Canyon’s wash. The debris flow spread out to roughly 250 feet in width and 5′ in depth after arriving in the wash. The flood took less than 5 minutes to travel between the Chuck Ballard Memorial Bridge and the New York Drive Bridge. With thousands of tree logs in transport, the extreme flow laid waste to several large stands of young Western Sycamores, White Alders, and Arroyo Willow trees. In just that time, the route of the creek switched channels in many locations, burying the previous channel used since 2005 in sediment and leaving once creek-side trees up to 50 feet removed from the new channel.

Observes looking over the fence at Midwick observed the flood pass by at 5:26 PM. 

Despite only 3.5″ of rain falling as a storm total, the torrential nature of the rainfall and burned hillsides were all that was needed to trigger the debris flow. However, the duration of the flood was limited due to the lower rain totals, preventing sediment erosion on the side of the wash experienced during other major floods in past decades. 

Based on a preliminary view of the park from the various (closed) trailheads looking in, the flood easily ranks in the top-5 largest floods of the past century, approaching the magnitude of the 1969 and 1980 floods. A more formal analysis in the coming months will need to be conducted to determine the full extent of the damage.  

Three hours following the flash flood, the creek level had dropped significantly. By the next morning, creek flow returned to a typical rate of flow often seen in winter and spring.

This past Monday, January 20th, 2025, the Los Angeles County Department of Public Works began clear cutting the Willow forests within the Eaton Reservoir below New York Drive. This project is being done in preparation of debris flows and significant sedimentation expected over the coming years now that Eaton Canyon has burned top-to-bottom. 

Following the devastating 1914 Southern California floods, the county created its Flood Control District to better protect the region. Several large canyons throughout the San Gabriel Valley, including Eaton Canyon and the Arroyo Seco, were significantly altered in the mid-1930s in an effort the lessen the impact of large floods. In addition, spreading grounds were dug to hold drinking water for the drier summer months. 

The Eaton Reservoir was originally meant to contain 948 acre feet of water when it was built in 1936. However, decades of flash flooding has deposited sand and gravel on the reservoir floor and left the reservoir only capable of holding 653 acre feet. This is a 31.1% loss in capacity. Efforts to clean out the reservoir and expand how much water the dam can contain before the next major flood hits are being prepared. 

In the early morning hours of Sunday, May 6, 2024, Eaton Canyon received another round of seemingly non-descript precipitation. A total of 0.31″ soaked the already green, lush canyon. The area had received 75.00″ – 100.00″ of precipitation over the past 18 months, and adding another third of an inch to those totals was nothing to write home about. Little did everyone know, however, that this would mark the end of an era.

Two hundred and forty six days later on January 6, 2025, Eaton Canyon was in a different place. In that time, a meager 0.08″ had fallen on the lower part of the park, setting a record at the official Pasadena weather station for driest May 7th – January 6th period in 118 years of weather record keeping. Each storm system throughout November and December failed to live up to expectations. The canyon had flipped from an immensely wet state directly into a bone dry one. This transition left the park with a tremendous amount of fuel that had also quickly dried out. The ingredients were set for a cataclysmic wildfire. All that was needed was wind.

During the second half of the 3 o’clock hour the following morning, a mountain wave windstorm rapidly spawned over Eaton Canyon. Winds quickly rose from calm conditions at 3:30 AM to winds of 55 MPH thundering down the canyon at 4:30 AM as recorded by the SoCal Edison Weather Station in the Equestrian Area. By dawn, park staff made the decision to close the park for the day due to the powerful winds. Strong winds continued to roar in the canyon to 65 MPH through 11 AM. Despite a 1.5 hour lull around noon, the winds returned in the afternoon. 

At 6:00 PM, a full 14 hours after the windstorm begun, winds continued to churn out of Eaton Canyon with occasional gusts to 65 MPH. At Henninger Helipad, winds of 85 MPH were recorded.

At 6:13 PM, on the evening of January 7, 2025, residents in the Canyon Close neighborhood looked outside and noticed an orange glow in the hills above. Allegedly, a branch blown off the mountain by high winds landed in the set of high tension wires that are draped across Eaton Canyon’s foothills. If this well-accepted scenario is confirmed by fire investigators, then this branch would have caused sparks to fly off the powerlines and land in the brush below the towers. As of the evening of January 13th, 2025, this explanation is officially unconfirmed. 

At 6:14 PM, the first 9-1-1 calls of a possible brush fire came in. Under extraordinarily high winds, dry fuels, and low humidity, the fate of Eaton Canyon was sealed right then and there. Firefighters were not going to be able to stop this one, and they knew it. The blaze took some time to get established, especially since many of the powerful winds were overshooting the steep mountain slopes and instead crashing into the surface on the canyon floor 500 – 2,000 feet ahead. However, emergency crews did not have enough time to respond. The erratic winds sent embers if every which direction, and the fire quickly exploded in size. 

As of the writing of this post, the #EatonFire has destroyed 7,000+ structures in Altadena, including 5,000+ homes. Sixteen community members have lost their lives. Over 14,117 acres have been “moonscaped” according to the County Fire Department. Upper Eaton Canyon, which has no record of seeing a wildfire in 80+ years, was destroyed. Entire neighborhoods in nearby Altadena were burned to the ground, and the California Governor has called this and the #PalisadesFire one of the worst natural disasters in U.S. history. 

MyEatonCanyon.com will do everything in it’s power to continue to bring the latest updates on the park. However, we can confirm that it will be years, not months, before the general public is allowed back in. 

Eaton Canyon has been hurt, and it needs peace and tranquility to recover. There will be a mad rush to get back in there to rebuild, restore, and rejuvenate. For now, though, the canyon needs a break. Please stay on the lookout for the latest from the Los Angeles County Department of Parks and Recreation as well as the Eaton Canyon Nature Center Associates on how you can help.