Chief Dave Winnacker, previously of Moraga-Orinda
Dave Winnacker is a nationally recognized expert on wildfire mitigation. He is a Hoover Institution Veteran Fellow at Stanford University, working on the intersection of wildfire and property insurance. He has served as the Western Fire Chiefs Association California Director, and as the California Fire Chiefs Association WUI Task Force lead. The Fire Break podcast calls him “a trailblazing figure in wildfire mitigation.” He has been used as an expert resource by the San Francisco Chronicle, PBS, the East Bay Times and many other mainstream media. The documentary “Weathered”, about the 2025 SoCal fires, relies on him to interpret the wildfire science issues that surfaced in the Pacific Palisades and Altadena Fires. After 21 years of career as a firefighter, he retired as the Fire Chief of the Moraga-Orinda Fire District last year.
Chief Winnacker just joined BFD as Assistant Fire Chief, and as the resident expert in wildfire mitigation. The following transcript recounts a 1.5 hour interview with him on May 20, 2025.
What made you decide on a career as a firefighter?
I stumbled into it. I grew up in Berkeley then went to UC Santa Barbara. After that I went into the Marine Corps. I had just come back from serving in Iraq, and was looking for something else. I ran into several firefighters who talked to me about what they did, and absolutely loved their work. They sold me! It has been, for me, a tremendously rewarding career.
What was the most seminal moment in your firefighting career?
In 2017, I led the strike team for the North Bay Fire (aka Coffee Park/ Santa Rosa/ Tubbs). Until then, I had primarily led fire fights in construction [igniting in constructed areas] where you win every time. It was the first time I truly saw fire unleashed, and what it can do to an unprepared community. During “regular” fires, despite the urgency, the firefighting process is very deliberate, and makes sure to avoid mistakes. But this fire moved so fast in space and speed: it gave us no time to put a solid command structure or be deliberate about our process. It simply outfought us.
Shortly afterwards, I became the fire chief in Moraga-Orinda. I had just seen effect of wildfire on an unprepared community. The district has relatively few issues, which allowed us to focus almost exclusively on planning for wildfire fighting in the wildland-urban interface. And we did.
What do you feel is the primary lesson you drew from your time at Moraga-Orinda?
I was able to spend a long time thinking about wildfire in the built environment and insurability. Exposure to wildfire risk is inevitable and preordained. The community has agency. Whether it succumbs to wildfire or not is dependent upon itself: we have a choice.
What caused you to accept to to come back in Berkeley?
I have a strong connection to the community—but, more importantly, I very much believe that we can change the risk that Berkeley is exposed to. Berkeley has a singular advantage over most communities exposed to high wildfire risk. Our risk, here, is limited to a single interface [The Grizzly Peak Mitigation Area, which faces Tilden Park] in a single weather scenario [Extreme Fire Weather, i.e. Diablo winds + high temperature + low humidity]. We can focus resources in singularly smaller section of the community. It is much easier than if you have to fight everything everywhere. Here, we can win.
What do you think is the likelihood of a wildfire coming into the Berkeley Ridge ?
A major wildfire coming in Berkeley is inevitable if you run time horizon far enough at human scale. We live in a fire-dependent landscape that is intended to burn. Climate change has increased temperatures and accumulation of fuel, and compressed the rain season. Our risks worsen with time.
What about our likelihood of loss of life?
It is not quantifiable, but high. The fire moves from east to west, and our narrow streets run from north to south. There will be losses.
Can we survive a wildfire on the Ridge in Extreme Fire Weather ?
Yes. If we are prepared, puny little men with tools can stop it.
How does Berkeley compare to Pacific Palisades in terms of wildfire? Can it happen here?
It is a different fuel type and terrain, but the built environment with exposed vegetation is similar. We have a greater surface area exposed to wildfire, and more ignition points here than Palisades. It is correct that, right now, temperatures and vegetation are a bit worse in southern CA: chapparal in Palisades, and, here, a mix of oak savanna (although this is not quite true any more there is so much more additional vegetation), Bay Laurel mix, and eucalyptus. In reality, though, the key factors are ERC (Energy Release Component), flame length and spread rate:. they can be the same there and here in wildfire conditions.
What is similar is that homes in Southern California that were prepared to receive wildfire, through defensible space and reasonable home hardening, did not burn. On the edge of the fire, where it was still an ember fire, a significant number of homes did not burn. As you get into the interior areas of the community, after the fire had turned into a structure-to-structure fire, an urban conflagration, you go from reasonably high survival rate on the edge to very low survival rate where they were subjected to structure fire.
Both here and in southern California, homes exposed to wildfire and prepared are unlikely to burn.
Outside of defensible space and of home hardening, what can we do to stop wildfire from destroying our neighborhoods?
Eucalyptus are not helpful, but getting rid of them does not solve the problem. There are no ukes in Pacific Palisades or Altadena, yet it burned to the ground. Lahaina and Marshall were grass fire, but they burned cities to the ground. In fact, in 1923 in Berkeley, also initially a grass fire, there was a eucalyptus plantation near the university that did not burn: the fire burned right around it. Once structures start to burn, it does not matter what vegetation there is. As for power lines, the first power line was installed in 1891, and there were plenty of fires before that. Even if every power line ends up buried, there will be plenty of fires after that.
Is it likely that a wildfire in the ridge would stop on Shattuck like the last time [1923]? Could it go all the way to the coast?
Everything is possible. But our fire will be wind driven, and wind events normally have a limited duration, likely 6-8 hours for Diablo winds. When the wind stops, we can extinguish a fire. The worst possible event depends upon the ignition point being proximal to the entry point [into the build area in Berkeley], and the ignition time being near the beginning of the wind event. Fire takes time to spread. If, on the other hand, the ignition point is 2 km east of Berkeley, and ignition occurs half an hour before the end of the wind event, the fire won’t get far. As a comparison, in 1923, there was a 2 hour 20 minute burn inside the city, which burned a square mile of town. In the 1991 Tunnel [Oakland] fire, the wind shifted after 6 hours.
Is the Berkeley Ridge defensible today? Would BFD position assets there and endeavor to defend it?
BFD will do what it can, but we have a low probability of success.
Can we make the Berkeley Ridge defensible and survive a wildfire?
The reality is that we are living in a fire-dependent landscape. We can not suppress wildfire ignitions—we can only stop wildfires borne of these ignitions. So, the only thing we can do is to make the houses at point of entry less likely to burn [home hardening] and make them take longer to ignite [defensible space]. We must harden the target—our home—and distance it from the source. Distance is a shielding tool to create separation between structure and burning fuel. It is very solvable.
What would it take to allow the Berkeley Ridge to survive a wildfire?
If you want to prevent concussion you wear helmet. If homes are prepared to receive fire they are unlikely to ignite. Wat we need to do, in priority order:
- screen vents, clean roofs and gutters, implement zone zero [no combustibles within 5 ft of the house].
- Then zone 1: break continuity of canopy and clear out brush.
- Then, create an extended fuel break in Wildcat Canyon.
But no fuel break will stop a fire. There is no future in which wildfire preparedness does not include actions in [home hardening] and around the home [defensible space: zone 0, 1, 2]. We have no choice. To fortify the ridge, we need to create defensible space and home hardening at scale, combined with work from surrounding environment [EBRPD et al.].
If you had a magic wand, what would you do to fortify the Berkeley Ridge against wildfire?
Within 400m of a wildfire we are exposed to massive amounts of embers. Homes at the interface [Wildcat Canyon and the Grizzly Peak Mitigation Area] will be exposed to massive amounts of embers. We have to slow down structure ignitions to allow a full buildup of firefighting personnel. Anything else will be very expensive and large ineffective. In an ideal world, every house would be rebuilt according to the full suite of chapter 7A [how they should be built according the the building code in the WUI today—there are only 40 houses in the Hills that date from the present time]. But redoing all ,windows, siding, decks, stairs, that is really expensive. What is practical and would work:
- Class A roof (if possible, also class A assembly)
- there are 100 wood shake roofs in the hills in total; they are a real problem and should get removed [because on average each one causes up to 10 more ignitions]
- Gutters cleaned or covered. When you walk around the Ridge, you see plenty of houses with a class A roof and bunch of needles on them—that is not a class A roof any more. To keep a class A roof you must maintain it clear of debris and tree litter
- Implement zone 0: no combustibles within 5 ft of a structure
- screened vents
When these 3 things are present, we get the vast majority of the benefits, and we will likely survive a wildfire. If we are not wiling to do those things, we should put our efforts and time into a rebuilding fund, because we certainly will not.
Eucalyptus cleanup is a good idea, but not an effective replacement to the above measures. it makes them more effective but it just an adjunct.
What can the Firewise leaders and organizers do to help make the Ridge as resilient to wildfire as it can be?
In the Moraga-Orinda fire district we were up to 42 Firewise neighborhoods. The vast majority of Firewise neighborhoods and leaders had not carried out mitigations. Having the Firewise leaders do the mitigations and get their homes in compliance is far more powerful than any number of public meetings I can give. Fear of the unknown is the major inhibitor of change. A Firewise leader who leads by doing can make their example resonate and cause many to stop fearing wildfire risk and start mitigating it.
A friend of mine likes to say: “Environmental and economic calamities have arrived without our permission.” The world is changing around us, quickly worsening wildfire risk. But we have agency to reduce our risk. It is our choice as to whether or not we choose to make this change. If we are concerned about wildfire and believe there is a risk that increase with climate change, we need to act.
You are a Hoover Fellow at Stanford specializing in insurance and risk issues. Will implementing EMBER help the home insurance crisis?
If we have reduced the risk we are more likely to surmount it.
Can we defend the Berkeley Ridge without EMBER?
I dont think so.
What are the 5 most important things you want to share with Berkeley Ridge residents about wildfire resiliency?
- Reality is limiting us: we cannot significantly reduce the probability of wildfire occurring (“ignition reduction”). There will always be a significant number of them—our efforts in making them disappear cannot be successful.
- Trying fuel mitigation in the surrounding landscape [EBRPD] is full of regulatory constraints that makes it, in practice, impossible in the foreseeable regulatory future. The mass of ignitable vegetation is so large that it would be very difficult anyway.
- The firefighters will be fighting wildfire only if, when they arrive, the residents have evacuated. If they haven’t, all resources will be rerouted to supporting evacuation—they won’t be fighting fires. The fighting response time is compounded by access issues and competition with evacuation.
- If we cannot buy time by slowing ignition of structure fires [through defensible space and home hardening], we will be unsuccessful. With more time to build up firefighting resources, this problem becomes solvable—we can win against wildfire.
- Experience counts. If you want to be successful at fighting wildfires, listen to what experienced firefighters know is key to being successful at fighting wildfires.
References
- Weathered: The REAL Story of the LA Fires | Full Documentary [56 minutes] | PBS Terra Chief Winnacker @ 20:58 & 48:01
- Firebreak Podcast: an interview with Dave Winnacker: When Fire Strikes: How Communities Can Survive and Thrive, with Chief Dave Winnacker - YouTube