Defensible Space

Create a Defensible Space Around Your Home!

What is defensible space? A defensible space is an area, either man-made or natural, where the vegetation is modified and maintained to slow the rate and intensity of an advancing wildfire.  Creating a defensible space also includes taking steps to protect your home from the ember storm that comes with a wildfire.

How do structures ignite?

Structures ignite when:

  • Nearby radiant heat is so intense it ignites the structure.
  • Fire burns right up to and touches the structure.
  • Firebrands collect in an exposed area and begin burning on or near the structure.

What is the purpose of defensible space?

  • To keep high intensity (crown) fire at least 100 feet away from a house by changing the fuel density so it can’t support that kind of fire. 
  • To keep low intensity (ground) fire at least 30 feet from house, keeping both radiant heat and direct flame contact from attacking the house.
  • To clean up and protect areas where firebrands and fuels can collect.

Here's how:

Thin tree and brush cover within 30 feet of the house.

  • Separate trees so their canopies are at least 10 feet apart.
  • Stands of 2 or 3 trees should be separated from the nearest tree or structure by at least 30 feet.
  • If the house is on a slope, increase the defensible space on the downhill side.  Calculate defensible space as follows:  3 feet for every 1 degree of slope.
  •  If the house is located at the crest of a steep hill, thinning should be done for at least 100 feet below the crest.

Limb up all trees within the defensible space.

  • Prune branches to a height of 10 feet above the ground.
  • Remove shrubs, small trees, and other potential "ladder" fuels (fuels which could allow a fire to climb into the crown of a tree) from beneath trees.

Mow dry grasses.

  • Keep all grass and weeds within the defensible space at a height of 2 inches or less, especially during periods of high fire danger.

Remove slash and ground litter.

  • Remove all dead limbs, leaves, the debris created by thinning and limbing, and other ground litter within the defensible space.

Trim branches near the house.

  • Remove branches which extend over the eaves of the house
  • Remove branches within 15 feet of a chimney.

Clean roof, gutters, and decks.

  • Clean your gutters regularly.
  • Remove all pine needles and leaves from where they gather on the roof, in the corners of decks, and anywhere they accumulate near or against the house. These can provide excellent tinder for the ember storm created by wildfires.

Thin surrounding forest.

  • Continue to thin trees within at least 100 feet of the house, separating them so that, at a minimum, crowns do not touch each other, and preferably so that there is a distance of 10 feet between crowns. The further out you can extend this thinning, the better.

Other things you can do to protect your house.

  • Stack firewood at least 30 feet away from your house.
  • Locate propane tank either on the downhill side or the same level as the house and at least 30 feet away from your house.
  • Install multi-pane or tempered glass windows, especially for picture windows and sliding doors.  These will withstand more heat before breaking than single pane windows. 
  • Use wire screens on all windows to stop embers from getting inside if the windows break during a wildfire.  The mesh holes must be no larger than 1/8" to stop embers.  Do not use fiberglass screens, which will melt.
  • Cover exterior attic, soffit and underfloor vents with wire mesh to prevent sparks from entering the house.  The mesh holes should be no larger than 1/8".
  • Enclose or screen off porch, foundation, roof, and attic openings to keep debris from accumulating underneath, and keep areas under decks free of vegetation.  Regularly clean these areas and anywhere needles accumulate.
  • Protect windows and sliding doors with nonflammable shutters, and use fire resistant drapes or blinds on the interior, especially on the side of the house which is most likely to be exposed to fire (typically the downhill side).
  • Install a chimney screen or spark arrestor, and inspect and clean your chimney on a
regular basis.
  • Equip your home with smoke detectors and at least one 10 pound ABC-class fire 
  • Post your address/house number so that it is clearly visible from the road, from both directions, and not obscured by brush and trees.  (See the Address Signs page for information on how to obtain an address sign from the Crystal Lakes VFD.)

For additional information on wildfire hazards and what you can do to reduce them, contact the Larimer County Wildfire Safety Coordinator at (970) 498-7718, or use the form on the Crystal Lakes Fire Protection District website to request to have members of the fire department perform a wildfire assessment on your lot.




Warning Sirens

For the safety of the community, Crystal Lakes Associations has evacuations sirens posted throughout the Association. The evacuation siren in case of failure of the dam is located near the Wapiti Mailsheds to cover the floodplain area and sounds like this whoop sound:

MP3 audio file [163.5 KB]

Property owners in the floodplain should evacuate immediately if they hear this siren; all other property owners should remain on their lots, to keep the roads clear for those evacuating the floodplain.


Sirens in ALL parts of the association will sound the fire evacuation siren if a wildfire threatens the community -- it sounds like this alert sound:

MP3 audio file [168.6 KB]

ALL property owners should evacuate IMMEDIATELY if they hear this siren. Emergency personnel will be on hand to help direct evacuating property owners out of the area.

Where to Find Us:

Crystal Lakes Fire Protection District (CLFPD)

237 Blackfoot Road

Red Feather Lakes, CO 80545

970-881-3521 (Phone)

970-881-2085 (Fax)


Crystal Lakes Volunteer Fire Department (CLVPD)

237 Blackfoot Road

Red Feather Lakes, CO 80545

970-881-3521 (Phone)

970-881-2085 (Fax)


Click here for a map.

How to Contact Us

For more information, feel free to contact us by telephone, email, or by using our contact form. We look forward to hearing from you!


CL FIRES is dedicated to education, planning, and support in the areas of fire prevention and safety, wildland fire mitigation, and personal safety in the greater Crystal Lakes Community of Larimer County, Colorado.


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