As Wildfires Continue to Burn, New Maps Shows Expansion of Wildland-Urban Interface

WASHINGTON, Sept. 10, 2015 – A new U.S. Forest Service report shows the continued expansion of housing development near forests, an area referred to as the Wildland-Urban Interface (WUI), with direct implications for the cost of wildfire fighting. Increasing densities of people and infrastructure in the WUI makes wildfire management more complex and requires more firefighting assets to ensure an appropriate, safe and effective response, which in turn drives up the cost of fighting wildfires. Expansion of the WUI has direct implications for wildfire management as more of the Forest Service's resources are spent each year to provide the firefighters, aircraft and other assets necessary to protect lives, property and natural resources in the wildland urban interface regions. In addition, overall fire seasons have grown longer, and the frequency, size and severity of wildland fires has increased.

In recent decades, research has shown a steady increase in the area that is part of the WUI, as documented and visually depicted in a new publication titled, "The 2010 Wildland-Urban Interface of the Conterminous United States." The percent of homes in the WUI increased by over five percent between 2000 and 2010 (latest data available). As of 2010, the WUI of the lower 48 states includes about 44 million houses, equivalent to one in every three houses in the country, with the highest concentrations of houses in the WUI in California, Texas and Florida. The publication includes new, high-resolution maps showing housing density, land ownership, land cover and wildland vegetation cover for each state.

"The expanding wildland urban interface is a critical issue for wildland firefighting and for the conservation of our forests," said Robert Bonnie. "More people, homes, and infrastructure are at risk than ever before. As the WUI grows, our fire fighters must commit greater resources to protect homes and property which dramatically increases the cost of fire suppression."

The cost of wildfire suppression reached a record $243 in a one week period during the height of suppression activity in late August. In 2015, 52% of the Forest Service budget was set aside for fire suppression, up from 16% in 1995. By September 2015, the Forest Service had already exceeded the funding set aside for fire suppression and was forced to borrow funds meant for other Forest Service activities. The bipartisan Wildfire Disaster Funding Act, already introduced in the House and Senate, is an important step forward in addressing the funding problems. The proposed legislation, which mirrors a similar proposal in President Obama's Fiscal Year 2016 Budget, would provide a fiscally responsible mechanism to treat wildfires more like other natural disasters, end "fire transfers" and partially replenish the ability to restore resilient forests and protect against future fire outbreaks.

While WUI expansion has increased the likelihood that wildfire will threaten structures and people and increase the number of people affected by wildfire, not all WUI acres are at high risk of wildfire or the only management concern. Increased risk of invasive species and disruption of wildlife and ecosystem processes often accompany human habitation, making the WUI maps an important guide in conservation work.

To download a copy of this publication, visit the Northern Research Station's website.

The mission of the Forest Service, part of the U.S. Department of Agriculture, is to sustain the health, diversity, and productivity of the Nation's forests and grasslands to meet the needs of present and future generations. The agency manages 193 million acres of public land, provides assistance to state and private landowners, and maintains the largest forestry research organization in the world. Public lands the Forest Service manages contribute more than $13 billion to the economy each year through visitor spending alone. Those same lands provide 20 percent of the Nation's clean water supply, a value estimated at $7.2 billion per year. The agency has either a direct or indirect role in stewardship of about 80 percent of the 850 million forested acres within the U.S., of which 100 million acres are urban forests where most Americans live.

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