Hazard Identification and Summary
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Annex F: CITY OF SACRAMENTO F.1 Introduction This Annex details the hazard mitigation planning elements specific to the City of Sacramento, a participating jurisdiction to the Sacramento County LHMP Update. This annex is not intended to be a standalone document, but appends to and supplements the information contained in the base plan document. As such, all sections of the base plan, including the planning process and other procedural requirements apply to and were met by the City. This annex provides additional information specific to the City of Sacramento, with a focus on providing additional details on the risk assessment and mitigation strategy for this community. F.2 Planning Process As described above, the City of Sacramento followed the planning process detailed in Section 3.0 of the base plan. In addition to providing representation on the Sacramento County Hazard Mitigation Planning Committee (HMPC), the City formulated their own internal planning team to support the broader planning process requirements. Internal planning participants included staff from the following City departments: Community Development Department Utilities Department Sacramento Fire Sacramento Police Department Media and Communication Additional details on plan participation and City representatives are included in Appendix A. F.3 Community Profile The community profile for the City of Sacramento is detailed in the following sections. Figure F.1 displays a map and the location of the City of Sacramento within Sacramento County. Sacramento County (City of Sacramento) Annex F.1 Local Hazard Mitigation Plan Update September 2011 Figure F.1. The City of Sacramento Base Map Sacramento County (City of Sacramento) Annex F.2 Local Hazard Mitigation Plan Update September 2011 F.3.1 Geography and Climate The City of Sacramento is located in the heart of California‟s Central Valley at the confluence of the Sacramento and American Rivers. The Great Valley is a flat alluvial plain approximately 50 miles wide and 400 miles long in the central portion of California. Its northern part is the Sacramento Valley drained by the Sacramento River, and its southern part is the San Joaquin Valley drained by the San Joaquin River. It is surrounded by the Sierra Nevada to the east, the Tehachapi Mountains to the south, Coastal Range to the west, and Cascade Range to the north. The topography of the area is relatively flat. There is a gradual slope rising from elevations as low as sea level in the southwestern portion of the Policy Area up to approximately 75 feet above sea level in the northeastern portion. Sacramento is the cultural and economic center of its six-county metropolitan area (El Dorado, Placer, Sacramento, Sutter, Yolo, and Yuba counties) and the largest city in the Central Valley. The regional location of Sacramento, as shown on the map above, is roughly halfway between San Francisco to the west and Lake Tahoe to the east. Sacramento covers a total area of approximately 99 square miles and is the seventh most populous city in California with a 2010 estimated population of 466,087. Sacramento has a Mediterranean climate that is characterized by mild winters and dry, hot summers. Rain typically falls between November and March, with the rainy season tapering off almost completely by the end of April. Average daily high temperatures range from the 50s in December and January to the 90s in July (with many days of over 100). Sacramento is accessible from Interstate 80 and U.S. Highway 50 (running east/west) and Interstate 5 and U.S. Highway 99 (running north/south). Amtrak serves Sacramento‟s passenger rail needs, while Sacramento International Airport (SMF) provides domestic and international flights through most major airlines. Within the city and surrounding region, Sacramento Regional Transit provides bus and light rail service. F.3.2 History Prior to European settlement, Nisenan (Southern Maidu) and Plains Miwok Indians lived in the area. In the early 1800s, the Spanish explorer Gabriel Moraga “discovered” and named the Sacramento Valley and the Sacramento River after the Spanish term for “sacrament.” Sacramento was founded during the California Gold Rush and grew quickly due to the protection of Sutter‟s Fort, which was established by John Sutter in 1839. The citizens of Sacramento adopted a city charter in 1849 and became the first incorporated city in California on February 27, 1850. During the California Gold Rush and through the 1800s, Sacramento became a major distribution point, a commercial and agricultural center, a terminus for wagon trains, stagecoaches, riverboats, the telegraph, the Pony Express, and the First Transcontinental Railroad, and in 1854 the state capital of California. Sacramento County (City of Sacramento) Annex F.3 Local Hazard Mitigation Plan Update September 2011 The city‟s current charter was adopted by voters in 1920, establishing a city council-and- manager form of government, still used today. The City expanded continuously over the years in the first half of the 1900s and in 1964 merged with the city of North Sacramento, just north of the American River. Large annexations of the Pocket area on the south and Natomas area on the north eventually led to significant population growth throughout the 1970s, 1980s, and 1990s. Sacramento experienced a massive growth in population in the 1990s and early 2000s. Primary sources of population growth are migration from the San Francisco Bay Area due to lower housing costs, as well as immigration from Asia, Central America, Mexico, Ukraine, and the rest of the former Soviet Union. From 1990 to 2000, the city‟s population grew by over 14 percent. F.3.3 Population In 2010, the total population for the City of Sacramento was at 466,087 by the US Census Bureau. F.4 Hazard Identification and Summary This section details how the risk varies across the Sacramento County planning area. Sacramento‟s planning team identified the hazards that affect the City and summarized their frequency of occurrence, spatial extent, potential magnitude, and significance specific Sacramento (see Table F.1). In the context of the plan‟s planning area, there are no hazards that are unique to Sacramento. Information on past occurrences and the likelihood of future occurrences is detailed in Section 4, Risk Assessment, of the base plan. Additional information for high and medium significant hazards for the City is included in the Vulnerability Assessment section of this Annex. Sacramento County (City of Sacramento) Annex F.4 Local Hazard Mitigation Plan Update September 2011 Table F.1. City of Sacramento Hazard Summary Frequency of Potential Hazard Occurrence Spatial Extent Magnitude Significance Agricultural Hazards: Occasional Limited Limited Low Insects/Pests Bird Strike Occasional Limited Negligible Low Dam Failure Occasional Extensive Catastrophic High Drought Occasional Extensive Critical Medium Earthquake Occasional Limited Critical Low Earthquake: Liquefaction Occasional Limited Critical Low Flood: 100/200/500-year Likely Critical Critical High Flood: Localized/Stormwater Highly Likely Significant Critical High Landslide Unlikely Limited Negligible Low Levee Failure Likely Significant Catastrophic Medium River/Stream/Creek Bank Likely Limited Limited Medium Erosion Severe Weather: Extreme Heat Likely Significant Critical Medium Severe Weather: Fog Likely Limited Limited Medium Severe Weather: Freeze Occasional Limited Limited Low Severe Weather: Heavy Rain Likely Significant Critical High and Storms Severe Weather: Tornadoes Unlikely Limited Limited Low Subsidence Likely Limited Limited Low Volcano Unlikely Limited Catastrophic Low Wildfire Occasional Significant Limited Medium Guidelines for Hazard Rankings: Frequency of Occurrence: Potential Magnitude: Highly Likely-Near 100 percent probability in next year Catastrophic-More than 50 percent of area Likely-Between 10 and 100 percent probability in next year or at least affected one chance in ten years Critical-25 to 50 percent Occasional-Between 1 and 10 percent probability in next year or at Limited-10 to 25 percent least one chance in next 100 years Negligible-Less than 10 percent Unlikely-Less than 1 percent probability in next 100 years Significance (subjective): Spatial Extent: Low, Medium, High Limited-Less than 10 percent of planning area Significant-10-50 percent of planning area Extensive-50-100 percent of planning area Source: AMEC Data Collection Guide Sacramento County (City of Sacramento) Annex F.5 Local Hazard Mitigation Plan Update September 2011 F.5 Vulnerability Assessment The intent of this section is to assess Sacramento‟s vulnerability separate from that of the planning area as a whole, which has already been assessed in Section 4.3 Vulnerability Assessment of the base plan. This vulnerability assessment provides an inventory of the population, property, and other assets located within the City and further analyzes those assets at risk to identified hazards ranked of medium or high significance (as listed in Table F.1) to the community. For more information about how hazards affect the County as a whole, see Chapter 4 Risk Assessment in the main plan. F.5.1 Total Assets at Risk This section identifies Sacramento‟s total assets at risk, including values at risk, critical facilities and infrastructure, natural resources, historic and cultural resources, and economic assets. Growth and development trends are also presented for the community. This data is not hazard specific, but is representative of total assets at risk within a