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CHAPTER 14. VOLCANO <br />14-5 <br />14.5.1 Population <br />The whole population of Kittitas County is exposed to the effects of a tephra. The populations most <br />vulnerable to the effects of a tephra are the elderly, the very young, and those already experiencing ear, <br />nose and throat problems. Homeless people, who may lack adequate shelter, are also vulnerable to the <br />effects of a tephra fall, although Kittitas County has few, if any, homeless people who would not be able to <br />find adequate shelter or assistance during an event. <br />14.5.2 Property <br />All of the property and infrastructure exposed to nature in the county is exposed to the effects of a tephra <br />fall. Vulnerable property includes equipment and machinery left out in the open, such as combines, whose <br />parts can become clogged by the fine dust. Since Kittitas County receives snow every year, and roofs are <br />built to withstand snow loads, most roofs are not vulnerable and would be able to withstand the potential <br />load of ash. Infrastructure, such as drainage systems, is potentially vulnerable to the effects of a tephra fall, <br />since the fine ash can clog pipes and culverts. This may be more of a problem if an eruption occurs during <br />winter or early spring when precipitation is highest and floods are most likely. <br />To estimate the loss potential for this hazard, a qualitative approach was used, based on recommendations <br />from FEMA guidelines on state and local mitigation planning. Loss estimation tools such as Hazus currently <br />do not have the ability to analyze impacts from volcano hazards. For this study, it was decided to use <br />0.1 percent as the loss ratio for the volcano hazard. Assessed valuations provided by the Kittitas County <br />assessor were the basis for these estimations. The results are summarized in Table 14-2. <br />Table 14-2. Ash Fall (Tephra) Loss Estimation <br />Jurisdiction Assessed Value Estimated Loss Potential at <br />0.1% Damage <br />Cle Elum $88,005,625 $88,006 <br />Ellensburg $894,213,490 $894,213 <br />Kittitas $66,114,260 $66,114 <br />Roslyn $67,559,830 $67,560 <br />South Cle Elum $8,747,100 $8,747 <br />Unincorporated $3,410,937,810 $3,410,938 <br />Total $4,535,578,115 $4,535,578 <br /> <br />14.5.3 Critical Facilities <br />All transportation routes are exposed to tephra accumulation, which could create hazardous driving <br />conditions on roads and highways and hinder evacuations and response. Machinery and equipment using <br />these transportation routes would also be vulnerable. Visibility in the short aftermath of an eruption would <br />be problematic. <br />14.5.4 Environment <br />The environment is highly exposed to the effects of a volcanic eruption. Even if the related ash fall from a <br />volcanic eruption were to fall elsewhere, it could still be spread throughout the county by the surrounding <br />rivers and streams. A volcanic blast would expose the local environment to many effects such as lower air <br />quality, and many other elements that could harm local vegetation and water quality. The sulfuric acid <br />contained in volcanic ash could be very damaging to area vegetation, waters, wildlife and air quality.