EVENT BRIEFING: October 2019 California Wildfires, Wind Events and Power Outages

October 30, 2019

Selim Günay and Khalid M. Mosalam

Key Lessons

❏ At the end of October, three significant fires took place in California, namely the Kincade Fire in Northern California and the Tick and Getty fires in Southern California, fueled by high speed winds with heated air blowing from inland to the ocean. California Governor Gavin Newsom declared statewide emergency due to fires and extreme weather conditions (CA Gov, 2019). PG&E shut down power for an estimated 2.35 million people across 38 counties at the same time increasing the severity of the situation.

❏ The planned PG&E power outages are similar to what could happen after an earthquake. Documenting the consequences of these power outages in terms of economic losses and other metrics can provide very useful regional data related to natural hazard extreme event resiliency.

❏ The power outages also highlight and demonstrate the interdependencies of infrastructure networks and provide a learning opportunity for the maintenance and coordination of infrastructure networks operated over cities and counties.

❏ Similar fires are likely to occur after earthquakes and other natural hazards, which present even a worse condition for structures because of the additional demands due to these extreme events.

The failures and damage during the Kincade, Tick and Getty Fires once again highlight the vulnerability of structures against fire and the need to improve fire performance, especially when subjected to multi-hazards. Considering the consequences of fires damaging and destroying many residential and commercial structures, it is required to develop not only fire-resistant techniques for buildings with valuable contents, but also economical solutions for residential and commercial buildings.

Overview

At the end of October, three significant fires took place in California, namely the Kincade Fire in Northern California and the Tick and Getty fires in Southern California, fueled by high speed winds with heated air blowing from inland to the ocean. California Governor Gavin Newsom declared statewide emergency due to fires and extreme weather conditions (CA Gov, 2019). PG&E shut down power for an estimated 2.35 million people across 38 counties at the same time increasing the severity of the situation.

Objectives of this briefing are 1) to provide details of the October 2019 California wildfires, wind events and power outages, 2) to describe damage to buildings and other infrastructure and disruption to the community in terms of downtime and economic losses, 3) to list key lessons learned in relation to earthquake and other hazards. Information provided here is based on various websites, news channels and CalFire, therefore does not include detailed field investigations.

Kincade Fire

The Kincade Fire started on 10/23/2019 at 9:27 PM in Sonoma County. The starting location is reported as the intersection of John Kincade Road and Burned Mountain Road, northeast of Geyserville with coordinates of 38.792°N, 122.78°W (Figure 1, Cal Fire, 2019a). At the time of the writing of this report, it is still ongoing with 74,000 acres burned (Figure 1, Los Angeles Times, 2019a) and has not been contained. How the fire initiated is still unknown and is under investigation. The fire destroyed 124 structures and damaged 23, including residential structures and wineries and other commercial construction (Figure 2).

Figure 1. Origin of the Kincade Fire (left, Cal Fire, 2019a) and burned areas (right, Los Angeles Times, 2019a)

Figure 2. Structures consumed during the Kincade Fire: A ranch house along State Highway 128 (left, Los Angeles Times, 2019b), Soda Rock Winery (right, ABC7 News, 2019)

About 180,000 people have been ordered to evacuate over a large area (New York Times, 2019). The spread area of the fire increased due to high winds with speeds up to 90 mph, known as Diablo winds, recorded Sunday (10/27/2019) morning. The normal weather pattern near the coast of California is for moist sea breezes to come off the Pacific Ocean and travel inland. But in the fall, high pressure that builds over the Great Basin in Nevada and Utah causes wind to shift in the opposite direction, creating the Diablo winds in Northern California and Santa Ana winds in Southern California (Los Angeles Times, 2019c). These winds are not only fast but also hot since they heat up as they descend on the west side of the Sierra, crossing the Central Valley and climbing over the Coast Range (Figure 3).

Figure 3. Diablo winds traveling from the high pressure inland towards the coastal lower pressure area during Fall (Los Angeles Times, 2019c)

These high winds and the potential risk of the power lines igniting fire are the main reason that PG&E shut down power for an estimated 2.35 million people across 38 counties starting from Saturday, 10/26/2019 (CBS SF Bay Area, 2019), including the areas affected by the Kincade Fire. These power outages are similar to what could occur after an earthquake. Therefore, documenting the consequences of these power outages in terms of economic losses and other metrics can provide very useful regional data related to natural hazard extreme event resiliency. Furthermore, these outages highlight and demonstrate the interdependencies of infrastructure networks (e.g. East Bay Municipal Utility District connected emergency generators and backup pumps to keep the water flowing during the PG&E power outage, EBMUD, 2019) and provide a learning opportunity for the maintenance and coordination of infrastructure networks operated over cities and counties.

Tick Fire

The Tick Fire started on 10/24/2019 at 2:51 PM in Los Angeles. The starting location is reported as the intersection of Tick Canyon Rd and Summit Knoll Rd, Canyon Country with coordinates of 34.473°N, 118.368°W (Figure 4, Cal Fire, 2019b). At the time of the writing of this report, it is still ongoing with around 4,000 acres (86%) contained. How the fire initiated is still unknown and is under investigation. The fire destroyed 22 structures and damaged 27, including residential and commercial construction (Figure 5). Similar fires are likely to take place after earthquakes, which represents even a worse condition for structures because of the additional demands due to earthquake.

These failures and damage during the Kincade and Tick Fires once again highlight the vulnerability of structures against fire and the need to improve fire performance, especially when subjected to multi-hazards. Similar to the Kincade Fire, the Tick Fire was fueled by winds blowing from inland to the ocean, named Santa Ana winds.

Figure 4. Origin of the Tick Fire and affected areas (Los Angeles Times, 2019a)

Figure 5. Structures consumed during the Tick Fire: A structure burning on Baker Canyon at Husk Ave (left, Los Angeles Daily News, 2019), A house burning on the Sequoia Road in Canyon Country (right, The Signal, 2019)

Getty Fire

The Getty Fire was reported just after 1:30 a.m. on 10/28/2019 by a witness who called California Highway Patrol and reported seeing flames on a hillside close to the 405 Freeway near the Getty Center museum (CBS Los Angeles, 2019). It is still ongoing over an area of 600 acres with mandatory evacuation orders in place (Figure 6, Los Angeles Fire Department, 2019). There are over 10,000 structures (both residential and commercial) in the mandatory evacuation zone with eight residences destroyed and six residences damaged. The Getty Museum, a hub of one of the largest art organizations in the world, is in the vicinity of the fire (Figure 6), which was designed and constructed to be earthquake and fire-resistant to protect its valuable artwork. Several features of the fire-resistant system are: 1) 1.3 million square feet of thick travertine stone, a highly fire-resistant material for the outside walls of the museum buildings, along with crushed stone on the roofs, 2) reinforced concrete walls and automatic folding fire doors able to trap fires inside certain locations, 3) air-conditioning system that can push smoke out instead of letting it in, 4) a 1 million gallon underground water-tank (USA Today, 2019). Considering the consequences of fires damaging and destroying many residential and commercial structures, it is required to develop not only fire-resistant techniques for buildings with valuable contents, but also economical solutions for residential and commercial buildings.