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as small as the Eugene/Springfield Metro Area, estimating the specific levels of damages and outages would require site-specific analyses. The potential impacts of major earthquakes on the Eugene/Springfield Metro Area are summarized below in Table 10.7. Table '10.7 Potential Impacts of Earthquakes on the Eugene/Springfield Metro Area Inventory Probable Impacts Portion of Eugene/Springfield Metro Area affected Entire City and surrounding region Many buddings w~ll have no damage or I~ght to moderate damage, Buildings w~th heavy damage concentrated ~n vulnerable buddings (wood frame buildings with cripple walls, unreinforced masonry, etc.). Total building damage estimated to be about $1,000,000,000. Streets within Metro Area Minor damage possible in areas of soft soils. Some bridges have moderate to extensive damage. Minor damage possible in areas of soft soils. Some bridges will Roads to/from Metro Area have moderate to extensive damage Electric power Short outage of electric power is hkely, with duration ranging from a few hours to 1 day. Generally moderate damage to water, wastewater and natural gas Other Utilities systems, ~nclud~ng p~pe breaks. Probable damage to water and wastewater treatment plants. Up to 30 deaths and about 1,600 injuries. Casualties wdl be Casualties h~gher for daytime earthquake than mghtt~me earthquake, because mostly wood frame residential buildings have lower I~fe safety risk, The above summary of potential impacts is for major earthquakes on the Cascadia Subduction Zone, as shown above in Tables 10.5 and 10.6. Smaller earthquakes would have generally substantially smaller impacts than shown above. In addition, there is a Iow probability that a major earthquake could result in substantial damage or failure of the major dams upstream of the Eugene/Springfield Metro Area. If dam failure were to occur, however, the impact on the Eugene/Springfield Metro Area could be very large with very high damage levels in inundation areas and potentially high casualties (depending on the extent of dam damage, the amount of warning time of dam failure, and the effectiveness of evacuations). ~10,5 Earthquake Risk Assessment: Technical Guidance For planning purposes, it is sometimes useful to consider three levels of earthquake risk assessment. A Level One Risk Assessment means that nationally available data are used. For example, FEMA's HAZUS loss estimation software uses national data and HAZUS risk assessments for a community are Level One. The risk assessments presented in the previous section were Level One Assessments made using methods and data very similar to 10-13