FORT COLLINS, Colo. – The number of people living in areas at risk to the effects of wildland fire increased by nearly 50 percent from 2012 to 2017, based on new Colorado Wildfire Risk Assessment data released this week by the Colorado State Forest Service.

As of 2017, approximately 2.9 million people live in Colorado’s wildland-urban interface (WUI) – the area where human improvements are built close to, or within, natural terrain and flammable vegetation – compared to 2 million people just five years earlier. The new figure represents approximately half of the state’s total population.

The source data are included in updates to the Colorado Wildfire Risk Assessment Portal, or CO-WRAP, which is an online mapping tool that helps Colorado community leaders, professional planners and interested citizens determine wildfire risk and where forest management actions can achieve the greatest impact to reduce risk.

The CSFS just completed a thorough update to the Colorado Wildfire Risk Assessment – and the data utilized for CO-WRAP – based on new housing, population, vegetative fuels, weather and other ancillary data. This is the first major update to the overarching site data since 2013.

“With the continued increase in Colorado’s wildland-urban interface population, it’s critical for landowners and communities to take actions to reduce their risk and address forest health concerns,” said Mike Lester, state forester and CSFS director. “The Colorado State Forest Service provides necessary resources to assist forest landowners and WUI communities to make their forests healthier and safer.”

Statewide wildfire risk assessment information

CO-WRAP first launched in 2013 and provides access to statewide wildfire risk assessment information. Through the web-based mapping tool, fire mitigation professionals, prevention planners, natural resource professionals and others can generate maps and download data and reports that describe defined project areas, such as communities or watersheds. The information in the portal is based on geographic information system (GIS) data layers that allow users to view such themes as potential fire intensity, historic fire occurrence and values at risk from wildfire.

New for 2018 is a statewide “burn probability” layer produced using an advanced GIS tool for modeling wildfire behavior and spread, based on millions of wildfire simulations.

Amanda West, CSFS science information manager, said that the increased population in the wildland-urban interface is due not only to more people moving into these areas, but also to better, more refined data and ongoing changes in land use and vegetation patterns.

She pointed out that the largest increases in population growth within the interface are in areas where agricultural lands are being converted to grasslands and subdivisions. Although these areas are considered in a low-risk category by the assessment, they are still at a higher risk for wildfire than more urban areas.

West said that with the update CO-WRAP still offers the same overall look and functions as before, and still features two levels of access – one for community leaders, planning professionals and forestry professionals, and one for interested citizens.

Hazard mitigation planning

The professional viewer provides access to data and tools for use in creating fire protection or forest stewardship plans, supporting Community Wildfire Protection Plans or identifying priority fuels treatment areas. It also allows users to generate detailed risk summary reports for customized land areas – such as neighborhoods, fire protection districts or counties.

“CO-WRAP offers a consistent dataset across Colorado to use for hazard mitigation planning,” said Kristin Garrison, CSFS fire, fuels and watersheds manager. “Whether you are focusing on the community level or watershed level, it provides baseline data for planning efforts.”

She said that new for 2018 is a statewide “burn probability” layer produced using an advanced GIS tool for modeling wildfire behavior and spread, based on millions of wildfire simulations. She also notes that the revised web portal focuses not only on the probability and potential intensity of wildfire, but also the values at risk from the negative effects of wildfire – such as homes, drinking water supplies and forest assets.

Addressing risk at the community or watershed level

West cautioned that CO-WRAP should not be used to determine parcel-level risk to individual homes, as it is instead scaled to address risk at the community or watershed level, and also should not be used to predict current fire danger.

“This is not a source for real-time fire risks or restrictions,” she said.

To access the updated CO-WRAP, go to www.coloradowildfirerisk.com. For more information about protecting homes and communities from wildfire, visit csfs.colostate.edu/wildfire-mitigation.