Guiding preventative wildland fire mitigation policy and decisions with an economic modeling system Keith Stockmann a, ⁎, James Burchfield b , Dave Calkin c , Tyron Venn d a USDA, Forest Service, Northern Region, 200 E. Broadway, Missoula, MT 59807, USA b College of Forestry and Conservation, University of Montana, Missoula MT, 59812, USA c USDA, Rocky Mountain Research Station, Forestry Sciences Laboratory, 800 East Beckwith Ave, Missoula, MT 59801, USA d Natural Resource Economics, College of Forestry and Conservation, University of Montana, Missoula MT, 59812, USA abstract article info Article history: Received 22 October 2008 Received in revised form 4 June 2009 Accepted 3 September 2009 Keywords: Wildland fire economics Preventative mitigation Firewise SIAM SIMPPLLE Cost-effectiveness analysis The protection of private residences from wildland fire produces high levels of cost and safety risk to firefighters, especially with the expanding ex-urban settlement pattern in the wildland urban interface (WUI). Economic information on probable structure losses can help guide efficient wildfire management, policy, and investments. However, no single existing modeling tool is capable of accurately predicting existing wildland fire ignition risk to WUI residences, nor are there broadly accepted models to calculate needed investments to reduce risk to WUI structures. To fill this void, a representative set of rural residences in western Montana was selected to estimate a baseline, 30-year wildland fire ignition hazard and the cost effectiveness of optional investments to reduce risk from wildfire damage to these residences. The study applied a modeling system combining outputs from a structure ignition assessment model (SIAM) with wildland fire probabilities from an ecological disturbance model (SIMPPLLE). Results indicate that the probability of structure damage to a home when a fire visits a residence is 1.0 under conditions of extreme wildland fire weather. This contrasts with the low probabilities (0–0.05) that wildland fire will reach vegetation surrounding the residence. Cost-effectiveness analysis of two suites of preventative mitigation strategies demonstrated that home mitigation zone investments (modifying houses or fuels within 30.5 m (100 ft) of a residence) are generally more cost effective in reducing risk to WUI structures than investments in silvicultural operations in surrounding forests (within 2.4 km (1.5 mi) of homes). The effectiveness of the mitigation options in modifying average home loss due to wildfire ranges from negative 19.6% to positive 63% (some silvicultural treatments did increase the probability of wildfire in simulations). While both home ignition zone mitigations and silvicultural treatments can markedly reduce wildland fire hazard estimates, the former appear to provide a more pronounced reduction in hazard as correlated with expenditures. Published by Elsevier B.V. 1. Introduction Residential developments in western US unincorporated areas adjacent to public lands have expanded substantially in recent years (Stein et al., 2005, 2007; NFAEB, 2005; US Census, 2001), raising a series of questions for land managers and planners. What actions should be taken to reduce wildfire risk to homes in the Wildland Urban Interface (WUI)? How can residents and fire suppression organizations reduce the costs of fighting fire? How does structure protection fit into a broader picture of public land management, including demands to sustain fire-adapted ecosystems? This research examines one of the most salient questions regarding human developments in areas with high levels of wildfire occurrence: How can individual homeowners and the public most effectively allocate available financial resources to protect residential WUI structures from wildland fire? By linking models of structure ignition and wild- fire probability in the most common forest type surrounding western WUI developments, this research examines the cost effectiveness of various preventative mitigation measures to protect structures from wildland fire. Implementation of the two most common approaches to reduce wildfire risk – Firewise activities, and thinning and prescribed burning silvicultural treatments – was modeled for a study area in the Bitterroot Valley of western Montana. Firewise mitigation efforts are actions taken to modify the residence itself as well as fuel conversions within the home ignition zone (HIZ). The HIZ was defined by Cohen (2001) as the area that principally determines the home ignition potential. The HIZ includes the home, its exterior materials and design, and the area around the home typically within 30.5 to 61 m (100 to 200 ft) (Cohen, 2001). In this study, the HIZ is defined as the area extending 30.5 m (100 ft) from each side of each structure. Firewise mitigations may be restricted by cost, ownership boundaries Forest Policy and Economics 12 (2010) 147–154 ⁎ Corresponding author. Tel.: +1 406 329 3549; fax: +1 406 329 3411. E-mail address: kstockmann@fs.fed.us (K. Stockmann). 1389-9341/$ – see front matter. Published by Elsevier B.V. doi:10.1016/j.forpol.2009.09.009 Contents lists available at ScienceDirect Forest Policy and Economics journal homepage: www.elsevier.com/locate/forpol