Item 26 - Adoption of the City of Santa Ana Emergency Operations Plan

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City of Santa Ana Emergency Operations Plan Part 1 Basic Plan Dams and Reservoirs - There are 44 dams in or near Orange County, whose ownership ranges from the federal government to homeowners' associations. These dams hold billions of gallons of water in reservoirs or lakes, which are designed to protect Southern California from floodwaters and to store domestic water. Seismic activity can compromise these structures resulting in catastrophic flooding to downstream communities. For example, the Prado Dam was constructed in Riverside County just across the Orange County line to protect central Orange County from flooding. Much of the City of Santa Ana lies within Prado Dam's inundation zone in the event of its failure or collapse. The City of Santa Ana owns 10 water reservoirs throughout the City (see Section 2.4.6). Damage to Critical Facilities - Critical facilities include police stations, fire stations, hospitals, shelters, government agencies and other facilities that provide essential services to the community. These facilities and their services need to be functional after an earthquake event. Businesses - Seismic activity can cause great loss to businesses, for both large corporations and small local businesses. When a company is forced to stop production for even a day, the economic loss can be tremendous, especially when its market is at a national or global level. Many small businesses do not reopen after a disaster or fail shortly thereafter. Businesses that close, temporarily or permanently, result in lost jobs and wages, lost tax revenue, and the inability of residents to acquire products and services necessary to maintain daily subsistence or to recover from their own losses. Debris - Damage to buildings, roadways and other structures will create a massive amount of debris, including brick and masonry, glass, wood, steel or concrete building elements, soil and roadway elements, home and business contents, and other materials. This will overwhelm the City's ability to remove the debris and overwhelm the ability of landfills and recycling and salvage operations to receive and dispose of debris. Future Earthquake Probabilities It is not possible to predict where and when an earthquake will occur, however it is possible to forecast the probability that a quake of a certain size will occur within a period of time. The Working Group on California Earthquake Probabilities is a multi -agency, multi -disciplinary team of earth scientists convened by the United States Geological Survey, the California Geological Survey and the Southern California Earthquake Center. In 2007, this group published the Uniform California Earthquake Rupture Forecast Version 2 (UCERF2), an update to an earlier earthquake forecast published in 1995. This study presents a forecast of the probability of future earthquakes occurring in California. The study primarily focuses on the probability of a magnitude 6.7 or larger earthquake occurring within 30 years. Magnitude 6.7, the magnitude of the 1994 Northridge earthquake, was selected as a benchmark to represent a damaging and deadly earthquake. The 30-year period was selected primarily to assist earthquake insurance providers in establishing insurance coverage, but also relates to the usual term of home mortgages and approximates one human generation. The UCERF2 forecast estimated the probability of a M6.7 or larger earthquake occurring somewhere in California within 30 years to be 99.7%. The probability of a M6.7 or larger earthquake occurring somewhere in the Los Angeles region, which encompasses Orange County, within 30 years is 67%. For Southern California (roughly from San Luis Obispo County southward), these probabilities were provided for the next 30 years: • M 6.7 or larger: 97% • M 7.0 or larger: 82% • M 7.5 or larger: 37% • M 8.0 or larger: 3% The southern California segment of the San Andreas Fault was rated as the most dangerous fault in California, having the highest likelihood for the next major earthquake, with a 59% probability of being the location of a M 6.7 or larger quake within 30 years. 40