Brush Fires

Conditions for Lower Keys Wildfires

Residents and firefighters must remain vigilant in dry conditions. Residents should report any fire immediately to 911. Residents in wooded areas should also take protective measures around their homes to create a defensible space, ideally 100 feet overall. The initial 30 to 50 feet of space surrounding a structure should be clean of fuel stockpiles such as wood, trash, and old vehicles.

Fires Beneficial for Pine Rockland Habitats

The pine rock land habitat needs fire to exist and the plants and animals that rely on the habitat have evolved with fire as a part of life. The resulting wildfire will likely benefit habitats in the long run and has certainly reduced fire fuel that has built up and been deposited by Irma.

Protecting Life and Property

The first and most important priority of the fire response is the protection of life and property and will remain so for the duration of the operations.

Fire lines are established on existing roads and trails where it was safe, reasonable, and strategic for firefighters to hold fire within a confined area and not let it out. 

Additional Information

Fire officials would like to remind residents to have a plan and be prepared during any fire threat.

Understanding a Brush Fire

Factors that influence the start and progression of a brush fire are Fuel, Weather & Topography.

FUEL: Debris, leaves, grass, trees, and any other combustible materials available in the fire area. On Big Pine Key, fuels vary in size and type. Hurricane debris and a build-up of local flora and fauna have created a prime fuel source for a fire.

WEATHER: A combination of wind, precipitation, relative humidity, and temperature all play roles in fire conditions. The current weather conditions of relatively low humidity, high temperatures, and shifting winds enhance conditions in which a wildfire can occur, as the existing fuels on Big Pine Key have continued to dry out.

TOPOGRAPHY: The terrain of Big Pine Key consists of wooded lots and homes with a large number of fuels. These environments allow the fire to move forward. Roads and yards that have defensible space create fire breaks that can stop or slow the progression of the fire. Defensible space is the cut and maintained areas of your property that are free of debris, combustible materials, and excessive brush growth.

Combining these factors, firefighters can create a fire behavior picture enabling them to understand the current and future direction of a brush fire allowing them to plan ahead for how best to use all resources on a fire operation.

Types of Brush Fires

  • Ground Fire: smoldering materials which typically move very slow
  • Surface Fire: fire that moves along the surface carried by leaves, grass, and deadwood.
  • Crown Fire: Fire in the tops of trees that ignites from below or moves from tree to tree.

Parts of a Brush Fire

  • Head: The fastest moving portion of the fire and typically the greatest flame length and rate of speed. Firefighters generally attack this portion of the fire.
  • Heel or Tail: the slowest moving portion of the fire, usually near the origin point
  • Flanks: side of the fire
  • Fingers: small areas that reach out from the main fire body

How Fire Spreads

Fire spreads by reaching out to available fuel. The head will move the fastest and flanks can grow outward while the heel moves slower. Fire can also spread by spotting. Embers, carried by wind or picked up in the smoke plume, can skip considerable distances over pockets of unburned fuel and fire breaks. This is how wildfires can become very large in a small amount of time.

Defensible Space: Clean, Lean, and Green

Defensible Space or fire-scaping is the natural and landscaped area around a structure that has been maintained and designed to reduce fire danger.

  • Clean: Ideally, a good defensible space is 100 feet overall. The initial 30 to 50 feet of space surrounding a structure should be clean of fuel stockpiles (wood, trash, old vehicles).
  • Lean: Thinning trees and shrubs works two-fold to hamper wildfire spread. It reduces the amount of burnable fuel around the structure and also increases the health of flora and fauna by opening space to provide more sunlight and oxygen. This reduces disease which can kill off plants and create more combustibles.
  • Green: A green and well-maintained lawn creates moisture, which lessens the chance of burning and spreading fire.