Fire Prevention in the Wildland Urban Interface (WUI)
How do I know if I live in a High-Risk Fire Area? If you live within Central County Fire Department jurisdiction, the high-risk areas are primarily within the Town of Hillsborough. For a map of those areas, click here. For privacy reasons, we do not post specific addresses. If you want to know if you live in this area, please call our offices and ask for our Fire Prevention Division, 650-558-7600. To view the Town-Council adopted WUI ordinance, click here.
Applying fire-safe concepts to your landscape is one of the most critical ways to help your home survive a wildfire. As conditions turn dry and windy, vegetation such as dry grasses, trees, and other vegetation surrounding your home can be a dangerous fuel source. Maintaining an area, which we call defensible space (an area of reduced fuel) between your home and potential fuel sources such as vegetation minimizes the risk of home ignition.
When your home and landscape are appropriately maintained to fire-safe standards, the threat to your home during a wildfire is reduced. Your home may be the most valuable investment you ever make. If you live in a high-risk fire hazard area, protect against the chance of losing that investment by implementing our fire-safe recommendations.
Many properties and homes in the Town of Hillsborough are within the Wildland Urban Interface (WUI) area. WUI is the transition between wildland (unoccupied land) and human development. Communities like Hillsborough are at a greater risk for wildfire and must take preventative action to eliminate hazards and reduce risks. The following pages contain best-practice actions all residents can take to reduce the risk of wildfire to their homes and our community. It will also help homeowners understand and implement the requirements for homes and properties within the designated WUI area. The Central County Fire Department is committed to working with residents to ensure Hillsborough is properly prepared and protected against wildfires.
What is Defensible Space?
Defensible space is essential to improve your home’s chance of surviving a wildfire. It’s the buffer you create between a building on your property and the grass, trees, shrubs, or any wildland area that surround it.
Defensible space is intended to slow or stop the spread of wildfire and protect your home from catching fire – either from direct flame contact or radiant heat. Understanding how fire spreads is the central concept behind defensible space. Often understood as a “fuel ladder” fire will spread vertically and horizontally where there is fuel available. The spacing between grass, shrubs, and trees is crucial to reducing the spread of wildfires. The spacing needed is determined by the type and size of brush and trees, as well as the slope of the land.
For example, a property on a steep slope with larger vegetation requires greater spacing between trees and shrubs than a level property that has small, sparse vegetation.
Creating an area of defensible space does not mean you need a ring of bare dirt around your home. Through proper planning, you can have both a beautiful landscape and a fire-safe home.
Defensible Space General Requirements
- Cut grass to no higher than 3”
- Limb up trees to 6 feet off the ground
- Cut bushes, shrubs, and trees so they are separated and don’t create a “fire fuel ladder”
- Maintain vertical clearance over roadways to 15 feet and 3 feet back on each side
- Maintain roofs and gutters free of dead leaves and pine needles
We hope our website helps you provide for a fire-safe home. Please view our WUI Resources page or you can always call us at 650.558.7600 and ask for our Fire Prevention Division to assist you.