Hazardous Fuels

The fuels assessment explains the potential for large damaging fires from a vegetation management standpoint. Appropriate fuel management strategies and tactical actions (including vegetation management, resource management, assistance to landowners, prevention, and more) are being developed and implemented.

The potential of a home being destroyed is related to its surrounding fuels. The fuel assessment allows the department to compare asset location to fuel hazard.

The fuel assessment was performed by merging maps from the California Department of Forestry and Fire Protection, the California Department of Fish and Game, Humboldt State University, the United States Forest Service, and the Marin Municipal Water District. Currently, the Point Reyes National Seashore is contracting for a very detailed vegetation-mapping project. Once completed, this data will be included in a future fire management plan.

Once a countywide map was created, vegetation was converted into fuel models that express how the vegetation would burn. The Fire Behavior Prediction System (FBPS) models were utilized as well as four custom models*:

Fuel Type FBPS Model
Annual grass Model 1
Grass under an oak understory Model 2
Mature chaparral Model 4
Coastal shrub Model 5
Oak-Bay-Madrone Hardwood Forest Model 8
Moderate conifer Model 9
Heavy conifer or eucalyptus Model 10
Urban areas Model 28*
Agriculture Model 97*
Water Model 98*
Barren Model 99*

*Custom models developed by the Fire Resource Assessment Program-California Department of Forestry and Fire Protection (Dave Sapsis)

Fuel models are used to mathematically express how fast and how hot a fire will burn. By using FARSITE, an advanced fire-modeling simulator, fire potential and mitigation strategies are validated prior to implementation.

The fuel models are compared to the slope deriving a fuel ranking. The slope classes are on flat ground and at the midpoints of the five National Fire Danger Rating slope classes.

The most hazardous fuel location is the Marin Municipal Water District watershed, which interfaces with the communities of Mill Valley, Larkspur, San Anselmo, Ross, Fairfax, and Woodacre. A majority of the federal land is ranked high or very high.

Appendix B includes the Fuel Methodology and Ranking Procedures

The following maps indicate the process and ranking for fuel in each Quad 81^st.

Detailed Fuel Map This is a large file and may take some time to download.

Slope Map

Fuel Ranking Map

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