Power Lines and the WUI

Photo from: LA Times

As fires continue to rage throughout California, investigations into the twelve fires that occurred earlier this year, and burned 245,000 acres, have been concluded. Investigators with Cal Fire have determined that these fires were caused by Pacific Gas & Electric Company power lines. High winds in the area caused trees and branches to fall onto the lines, and in at least one case a power pole failed and collapsed. PG&E currently has a vegetation control program in place with a budget of $400 million per year.

NFPA 1, Fire Code provides clear guidance on how to prevent fires from electrical lines. Chapter 17, Wildland Urban Interface outlines the following  requirements for vegetation clearance around electrical transmission and distribution lines, conductors, and their appurtenances.

• 10 feet clearance is required around all poles or towers
• At the time of trimming, the following minimum clearances should be provided based on the line voltage:

• As the growth returns, it is permitted to grow to within the clearances shown in the table below. Once this minimum distance is reached vegetation must be trimmed back to the required minimum clearance.

                             

• The AHJ has authority to adjust clearance requirements based on local needs or conditions, and vegetation type

Preventing Fires in the Wildland/Urban Interface (WUI)

So far, this year the United States has experienced 52,699 wildfires. These fires have burned nearly 9 million acres, destroyed 8,700 structures, and claimed 23 lives, and will cost insurers $3 billion.

NFPA 1452 defines the wildland/urban interface (WUI) as “the presence of a structure in locations in which the AHJ determines that topographical features, vegetation fuel types, local weather conditions, and prevailing winds result in the potential for ignition of the structures within the area from flames and firebrands of a wildland fire”. According to the Verisk 2017 Wildfire Risk Analysis nearly 4.5 million homes meet this definition, and are considered to be at high or extreme risk of wildfire.

What can fire prevention organizations do to mitigate the wildland fire risk and how can we prepare our communities for these wildfire disasters?

A house threatened by wildfire, by USDA

The critical area that homeowners have the most control over is known as the “structure ignition zone”. This is a radial area around the home of up to 200 ft.  NFPA 1452, Chapter 9, recommends the following actions should be completed to prevent ignition from nearby flames or floating firebrands.

1. Maintain a buffer zone of at least 30 feet around the home. Plant only  high-moisture, drought resistant, and low-flammability vegetation next to, and within the first 6 feet of, the home’s foundation.
2. Use only noncombustible roof materials.
3. Ensure that the roof and gutters are always clean or debris, pine needles, and dead leaves.
4. Install 1⁄4 in. mesh metal screens over foundation and eave vents
5. Enclose the sides of stilt foundations and decks
6. Providing metal screens or spark arresters on chimneys
7. Maintain access to emergency water supply sources such as, swimming pools, wells, ponds, and lakes.
8. Follow all local open burning regulations.

Residents living within the wildland/urban interface should be prepared for evacuations in the event that mitigation's fail, or extreme circumstances prevail.  Residents can be prepared for wildfire by making the following arrangements.

1. Have an evacuation plan, and be knowledgeable of exit routes and shelter locations.
2. Inventory the home and possessions with videos or photographs.
3. Secure important documents off-premises (safe-deposit box, etc.).
4. Identify those important items to be brought in the evacuation.
5. Keep a bag of personal care hygiene items, for use at evacuation shelters.

For more information and tools on the wildland/urban interface, homeowner safety, and firefighting operations, a valuable resource is the NFPA Firewise USA website at, FireWise.org.

Prescribed burning in 100 seconds

Don't understand what a controlled burn is all about?  Looking for a good resource for educating your community on wildfire?  Check out this video.  This animation explains forest management, fuels management, and prescribed burning...in less than 100 seconds.

No Time To Burn - Inside California Wildfire ICS

Take a rare look inside the strategy sessions between the California Emergency Management Agency, California National Guard and CAL FIRE during the beginning of the 2012 wildfire season.

No Time to Burn from CalEMA on Vimeo.

Florida Firewise Resources

With the active wild fire season (especially here, in Florida) upon us, many people are concerned about protecting there lives and property.  The National Fire Protection Association created the Firewise Communities Program to address these very concerns. 


The NFPA gives the following general safety guidelines:

• 

  If you're moving to a new home in a rural area or buying land to build a new home, do a thorough outdoor fire safety check before you proceed. Locate the home on the lot with adequate setback from downhill slopes. Wildland fire travels uphill rapidly – make sure that your home won't be in its path.
• Make sure that the area has adequate public fire protection available. Will emergency vehicles have easy access to the house? Is your address clearly visible from the road? Will firefighters have access to a water supply to put out a fire?
• Make your roof fire safe. Untreated wood shake roofs are the leading cause of wildland fire losses. A roof made of fire-resistant or non-combustible materials can make your home safer. Also, use non-combustible (metal) screening in eave vents and for windows.
• Sweep gutters, roofs, and eaves regularly and remove dead branches from around or near chimneys. Burning firebrands or embers can collect in the same space that leaves and pine needles do. Remove leaves and needles from cellar window walls and from corners and crevices around the outside of your home.
• Create a survivable space, safety zone or "fire break" around your home. Flammable (highly resinous) plants, woodpiles, and debris should be kept as far away from the exterior walls of the home as possible. Fences, decks, or outbuildings connected to the house must be considered part of the house; construct them out of non-combustible materials and keep them clear of pine needles, dead leaves, etc

  
  

  

  Here is a list of resources for Florida wildfire protection:

  
  

  
  • Schedule a Firewise workshop, get a community Wildfire Risk Assessment, or get local wildfire information: Florida Division of Forestry Wildfire Mitigation Specialists:  http://www.fl-dof.com/wildfire/firewise_contacts.html 

  
  •  General Firewise Communities Information: http://www.fldof.com/wildfire/firewise_index.html 

  
  •  Wildfire Risk Reduction in Florida- Home, Neighborhood, and Community Best Practices:  http://www.fl-dof.com/wildfire/wf_pdfs/Wildfire_Risk_Reduction_in_FL.pdf 

  
  •  Fire in Florida’s Ecosystems fire education curriculum and resources for grades 3-12: www.fireinflorida.org

  
  •  Florida Wildfire Prevention online education for grades 3-12: http://floridawildfireprevention.com/