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CHAPTER 10. EARTHQUAKE <br />10-19 <br />etc. Whether directly impacted or indirectly impact, the entire population will have to deal with the <br />consequences of earthquakes to some degree. Business interruption could keep people from working, road <br />closures could isolate populations, and loss of functions of utilities could impact populations that suffered <br />no direct damage from an event itself. <br />10.5.2 Property <br />The Kittitas County Assessor estimates that there are 15,364 buildings in Kittitas County, with a total <br />assessed value of $4.54 billion. Since all structures in the planning area are susceptible to earthquake <br />impacts to varying degrees, this total represents the countywide property exposure to seismic events. <br />10.5.3 Critical Facilities <br />All critical facilities in Kittitas County are exposed to the earthquake hazard. Chapter 4.5 of this plan lists <br />the number of each type of facility by jurisdiction. Hazardous materials releases can occur during an <br />earthquake from fixed facilities or transportation-related incidents. Transportation corridors can be <br />disrupted during an earthquake, leading to the release of materials to the surrounding environment. <br />Facilities holding hazardous materials are of particular concern because of possible isolation of <br />neighborhoods surrounding them. During an earthquake, structures storing these materials could rupture <br />and leak into the surrounding area or an adjacent waterway, having a disastrous effect on the environment. <br />10.5.4 Environment <br />Secondary hazards associated with earthquakes will likely have some of the most damaging effects on the <br />environment. Earthquake-induced landslides can significantly impact surrounding habitat. It is also possible <br />for streams to be rerouted after an earthquake. This can change the water quality, possibly damaging habitat <br />and feeding areas. There is a possibility of streams fed by groundwater drying up because of changes in <br />underlying geology. <br />10.6. VULNERABILITY <br />Earthquake vulnerability data was generated using a Level 2 Hazus analysis. Once the location and size of <br />a hypothetical earthquake are identified, Hazus estimates the intensity of the ground shaking, the number <br />of buildings damaged, the number of casualties, the damage to transportation systems and utilities, the <br />number of people displaced from their homes, and the estimated cost of repair and clean up. <br />10.6.1 Population <br />A geographic analysis of demographics, using the Hazus model and data from the U.S. Census Bureau, <br />identified populations vulnerable to earthquake hazards. The information was pulled from Census Blocks <br />that intersected the floodplain as follows: <br />• Economically Disadvantaged Populations— Approximately 1,700 households in the <br />planning area census blocks that intersect NEHRP D and E soils are listed as being <br />economically disadvantaged, defined as having household incomes of $10,000 or less. This is <br />about 12 percent of all households in these census blocks, and about 10 percent of the overall <br />number of households. These households lack the financial resources to improve their homes <br />to prevent or mitigate earthquake damage. Poorer residents are also less likely to have insurance <br />to compensate for losses in earthquakes. <br />• Population Below Poverty Level— Approximately 4,800 households in the planning area <br />census blocks that intersect NEHRP D and E soils are listed as being below the poverty level <br />($30,00 a year or less). This is about 35 percent of all households in these census blocks, and