Wildfire FAQ & Resources

In the aftermath of the Woolsey Fire and other extreme fire events in southern California, there has been significant community interest about fire safety and how the management of vegetation on our local open spaces can contribute to community safety. As land managers, we take our stewardship responsibilities seriously and strive to carefully balance our land management priorities to promote a healthy and safe environment. COSCA’s land management as related to fire is based primarily on scientific approaches along with meeting the requirements set forth in the Ventura County Fire Code.


To help our community understand our land management decisions we have developed some answers to the most frequent questions we receive.


Q: What is the fire risk in the Conejo Valley? Is fire risk a new phenomenon?


A: Fires have always been a feature of the Conejo Valley’s landscape. With a natural return period of 30-100 years and the absence of homes, fire could be called a natural feature rather than a “threat”. Fire becomes a threat, both to homes and the environment, when structures are built in a fire-prone landscape and when human-caused ignitions become more frequent. Additionally, the threat of large destructive fires is closely associated with extreme wind events (Santa Ana Winds), which are also a regular annual feature of our region. Research has shown that destructive fires in our region are driven principally by our region’s weather variables (wind) and human-caused ignition sources more so than fuel conditions. Since all of the Conejo Valley lies in a high-risk fire area, there have always been and will always be fire threats here. Community safety will rely on a combination of preventing human-caused ignitions (from people or infrastructure) and protection of structures through a combination of defensible space creation, home hardening, community planning, and strategic deployment of fire-fighting resources.




Q: What is COSCA doing to protect neighboring homes from wildfires?


A: COSCA has a comprehensive defensible space program under which we actively manage vegetation where our properties abut communities. Each year COSCA, the City of Thousand Oaks (CTO) and the Conejo Recreation and Park District (CRPD) receives notice from the Ventura County Fire Department (VCFD) for all parcels where the defensible space buffer (100 feet from structures and 10 ft from roads) crosses into COSCA / City / CRPD property. The three agencies partner on this work through a single program. We subsequently complete the fuel modification to the Ventura County Fire Department’s satisfaction, at which time they confirm that the required fuel treatments are complete. The purpose of the defensible space program is to reduce fuel density within 100 feet of a home or structure. This buffer zone gives space to fire fighters and other first responders to protect homes and keeps the radiant heat and direct flames of fires far enough away to prevent structure ignition.



Q: Why is the defensible space buffer 100 feet in width? Wouldn’t more vegetation removal be better?


A: One hundred feet is the distance prescribed by the Ventura County Fire Department and is supported by abundant scientific literature showing that, in chaparral and sage scrub habitats, additional vegetation removal does not yield additional protection for homes. COSCA also has a responsibility to protect the environment within our open spaces, and our vegetation is what defines habitat and nature within our open spaces. Retaining this vegetation protects habitats and prevents excess soil erosion.


We note that in wind-driven fires, 100 feet of defensible space may not be enough to protect a home. In the recent Woolsey Fire, blowing embers / firebrands easily jumped 8 lanes of the 101 freeway, as well as igniting homes far from our open space areas. In these cases, winds were a greater contributor to fire spread than fuel volume. See below for information about blowing embers.


Research Links:

The Role of Defensible Space for Residential Structure Protection During Wildfires

How Much Defensible Space is Needed to Reduce Home Losses in Chaparral?



Q: What about blowing embers?


A: In wind-driven fires, embers are often the primary source of home ignitions. Therefore, the actions taken by homeowners in the immediate vicinity of the home are the most important in protecting the home. In these extreme fire events, embers blow well out in front of the main fire line and can ignite homes more than a mile away. No practical amount of vegetation removal from open space can prevent embers from blowing into homes. Therefore, it is very important for homeowners to take the steps necessary to make their homes fire safe. The Ventura County Fire Department has prepared a guide for homeowners to help prevent embers from starting fires in their homes. You can download a copy here.  Additional information from the Ventura County Fire Department can be found here. Protecting larger neighborhoods requires all homeowners to work together as a single home ignition can rapidly spread to adjacent homes.


Fire Spread on Ember-Ignited Decks – wildlandfiresg.org

Wildfires Can Attack Your House From the Inside — Here's How to Prevent It – KQED, 10/30/2017.

Wind-driven glowing embers pose a greater threat to homes than fire itself – LA Times, 8/3/2008.



Q: Why doesn’t COSCA use goats to manage vegetation on open space?


A: The choice of methods used to manage vegetation depends largely on the specific goal for vegetation management, and different methods yield different results. COSCA’s primary goals in our open space is to steward the natural landscapes that create wildlife habitats, provide stability on steeper slopes, and to do our part in creating defensible space. In the defensible space buffers, our goal is to reduce the density of vegetation to prevent radiant heat and flames from impacting homes.


Goats can be very efficient at removing vegetation, but they do not differentiate between the native plants we want to protect and the weedy plants we’d want to remove. Our human crews can be more selective. Our defensible space areas are also mostly small areas and the logistics of moving animals in and out would be logistically difficult and more costly than human operators, especially in years when we have so much re-growth that multiple treatments of some areas are required. The ideal minimum size for a grazing unit is about an acre.


We are not using goats over larger acreages because they would cause damage to recovering native plant communities and negatively impact the recovery after being burned. When significant vegetation is removed from a hillside it leads to greater erosion.  Even the weedy plants that sprout first after the fire help stabilize soil while native plant communities recover. In many places we are seeing re-growth of native plants among these weeds, but it will take 5-7 years to see a significant recovery following the Woolsey Fire.


While COSCA does not use goats for annual fuel modification related to fire safety, goats and other livestock can be viable tools in land management when the goals of the project are aligned with the capabilities of the animals. For instance, goats are often used to remove weeds on remote and steep hillsides where it is logistically difficult to deploy people. This can be helpful when weed management is integrated into a restoration effort. The difference between using them for restoration and fuel management is that restoration would use the animals for short durations and include re-planting or casting seeds for native vegetation. The intensity of grazing would then be modified as native plants return. When COSCA has the resources to implement larger area restoration projects, we will certainly consider livestock as a tool for these projects.



Q: Isn’t it good for chaparral and coastal sage scrub plant communities to periodically burn?


A:  No. While these habitat types are resilient to fire, they do not need fire to persist and more frequent disturbance will cause them to convert to weedy herbaceous landscapes dominated by vegetation that is more flammable. Learn more about chaparral and wildfire from the Chaparral Institute here.


The conversion of one habitat type to another is called type-conversion. A brief description of this process can be found here. COSCA manages land to prevent type-conversion because there are so many species of wildlife that depend on chaparral and coastal sage scrub habitats for their survival.


Here is a short video explaining why COSCA and other conservation agencies value our chaparral ecosystems.



Q: Would prescribed burns better protect homes?


A: No. Much for the same reason we are not using livestock such as goats, repeated disturbance would cause significant environmental damage while providing no additional value in protecting homes. There has been much talk about using prescribed burns at the state-wide level, but this land management practice is almost always used in pine forest lands. The Conejo Valley does not have pine forests, so this management technique is not applicable here. It is important to note that different habitat types and plant communities require different management practices and using the wrong practices causes substantial damage to local plant communities and the wildlife that depend on them.


More Articles and Links About Land Management and Wildfires:


New USGS research on 21st century California wildfires examines drivers of fire behavior and structure losses


Fuel Management and Wildfires - LA Times, 9/11/2019.


Will Cal Fire’s plan to rip out vegetation in San Diego lead to an explosion in flammable invasive grasses? - The San Diego Union-Tribune, 9/30/19.


Wildland Fire Safety Starts in the Home – University of California Cooperative Extension


S.A.F.E. Landscapes – University of California Cooperative Extension





COSCA is a joint powers agency between the City of Thousand Oaks and Conejo Recreation and Park District

2100 Thousand Oaks Blvd., Thousand Oaks, CA 91362   |   805.449.2345

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