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CHAPTER 15. WILDFIRE <br />15-2 <br />year, compared to 10,143 fires caused by lightning annually. Fires during the early and late shoulders of <br />the fire season usually are associated with human-caused fires; fires during the peak period of July, August <br />and early September often are related to thunderstorms and lightning strikes. <br />15.2. HAZARD PROFILE <br />15.2.1 Physical Conditions <br />Fuels <br />Fuels that contribute to wildfires in Kittitas County range from sagebrush/grass to various types of conifers <br />in the upper county. Fire exclusion and lack of thinning have resulted in dense stands of vegetation that act <br />as ladder fuels. In the lower elevations, sagebrush, grass and weed areas provide fuel for wildfire spread <br />and increased intensity. Drought, combined with these vegetation types, provides additional dead vegetation <br />to fuel future wildfires. Other fuels are slash from logging and clearing for development. Homes in the <br />wildland urban interface (WUI) are also fuel. <br />Weather <br />High temperatures in Kittitas County during wildfire season dry out fuel sources, allowing fuels to ignite <br />and burn faster. Low humidity and lack of precipitation also increase the chance of wildfire ignition. The <br />dry windy weather of Kittitas County can cause wildfires to grow quickly and can carry firebrands a mile <br />or more from the original fire. Drought conditions must be taken into consideration, because drying <br />vegetation can ignite and burn more easily. <br />Insect Damage <br />Mortality caused by the western pine beetle may be increasing over historical levels. Where there are more <br />small Ponderosa pine present, moisture competition is high, which results in small stands that are of poor <br />vigor. This can cause an increase of beetle infestation. Once the infestation begins in the small trees, they <br />often attack large healthy Ponderosa pine still present in the stand. Wes tern pine beetle is now the most <br />common tree-killing beetle in second growth Ponderosa pine stands on the Wenatchee National Forest. Pole <br />and small saw timber-sized trees, especially those in dense stands, are also affected. These trees are <br />important for future replacement of the older Ponderosa pine removed by past harvesting. <br />Douglas fir beetle attacks have also become more frequent. Trees defoliated by the western spruce budworm <br />are especially susceptible to attack by this insect. Some of the most serious damage occurs in riparian areas, <br />putting these sensitive ecosystems at increased risk to future fires because an attack by certain insects can <br />leave large patches of dead trees which dry out and will more easily ignite (Mason Community Countywide <br />Fire Protection Plan, 2005). <br />15.2.2 Wildland Urban Interface <br />Wildland urban interface areas are areas that lack adequate fire flow and areas outside a fire district. In <br />heavily timbered mountainous regions or sparsely populated areas, each jurisdiction designates additi onal <br />WUI areas. As more development extends deeper into these regions, the risk of wildfire interacting with <br />these residences increases. A WUI analysis conducted by the National Fire Protection Association for <br />Kittitas County suggested that 33 percent of the region is classified as “high risk” for wildfire. Parcel <br />delineation activity from 2001-2006 showed that approximately 60 percent of new parcels fall within the <br />high-risk WUI areas (McColl, 2007).