Chapter 4.3 Vulnerability Assessment
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4.3 Vulnerability Assessment Requirement §201.6(c)(2)(ii): [The risk assessment shall include a] description of the jurisdiction’s vulnerability to the hazards described in paragraph (c)(2)(i) of this section. This description shall include an overall summary of each hazard and its impact on the community. Requirement §201.6(c)(2)(ii)(A): The plan should describe vulnerability in terms of the types and numbers of existing and future buildings, infrastructure, and critical facilities located in the identified hazard areas. Requirement §201.6(c)(2)(ii)(B): [The plan should describe vulnerability in terms of an] estimate of the potential dollar losses to vulnerable structures identified in paragraph (c)(2)(i)(A) of this section and a description of the methodology used to prepare the estimate. Requirement §201.6(c)(2)(ii)(C): [The plan should describe vulnerability in terms of] providing a general description of land uses and development trends within the community so that mitigation options can be considered in future land use decisions. With Sacramento County’s hazards identified and profiled, the HMPC conducted a vulnerability assessment to describe the impact that each hazard would have on the Sacramento County Planning Area. The vulnerability assessment quantifies, to the extent feasible using best available data, assets at risk to natural hazards and estimates potential losses. This section focuses on the risks to the County as a whole. Data from the individual participating jurisdictions was also evaluated and is integrated here and in the jurisdictional annexes, and noted where the risk differs for a particular jurisdiction within the Planning Area. This vulnerability assessment followed the methodology described in the FEMA publication Understanding Your Risks—Identifying Hazards and Estimating Losses. The vulnerability assessment first describes the total vulnerability and values at risk and then discusses vulnerability by hazard. Data Sources Data used to support this assessment included the following: ArkStorm at Tahoe - Stakeholder Perspectives on Vulnerabilities and Preparedness for an Extreme Storm Event in the Greater Lake Tahoe, Reno and Carson City Region. 2014. birdnature.com Pacific Flyway California Adaptation Planning Guide Cal-Adapt CAL FIRE GIS datasets California Department of Finance, E-1 Report California Department of Finance, E-4 Report California Department of Finance, P-1 Report California Department of Fish and Game's Natural Diversity Database California Department of Food and Agriculture Sacramento County 4-192 Local Hazard Mitigation Plan Update December 2016 California Native Plant Society California Office of Historic Preservation County GIS data (hazards, base layers, and assessor’s data) Delta Risk Management Strategy. June 2011. Existing plans and studies Federal Aviation Administration National Wildlife Database FEMA’s HAZUS-MH 2.2 GIS-based inventory data FEMA Digital Flood Insurance Rate Map. June 16, 2015. FEMA Sacramento County Flood Insurance Study. June 16, 2015. Liu, J.C., Mickley, L.J., Sulprizio, M.P. et al. Climatic Change. 138: 655. doi:10.1007/s10584-016- 1762-6. 2016. Kenward, Alyson PhD, Adams-Smith, Dennis, and Raja, Urooj. Wildfires and Air Pollution – The Hidden Health Hazards of Climate Change. Climate Central. 2013. National Drought Mitigation Center – Drought Impact Reporter National Park Service – Historic American Buildings Survey and Historic American Engineering Record Personal interviews with planning team members and staff from the County and participating jurisdictions Preliminary Draft – Climate Change Vulnerability Assessment for the Sacramento County Climate Adaptation Plan Sacramento County 2035 General Plan Sacramento County Department of Water Resources Sacramento County General Plan Environmental Impact Report Sacramento County General Plan Open Space Element Background Sacramento County of Governments Population Projections for 2008, 2020, and 2035 Sacramento General Plan Background Report Sacramento Municipal Utility District Dam inundation maps South Sacramento Habitat Conservation Plan State Department of Water Resource’s Delta Atlas Statewide GIS datasets compiled by the California Office of Emergency Services to support mitigation planning University of California – Integrated Pest Management Program US Census Bureau 2010 Household Population Estimates US Department of Agriculture Farm Service Agency US Fish and Wildlife Service US Fish and Wildlife Service’s National Wetlands Inventory maps Written descriptions of inventory and risks provided by participating jurisdictions 4.3.1. Sacramento County Vulnerability and Assets at Risk As a starting point for analyzing the Planning Area’s vulnerability to identified hazards, the HMPC used a variety of data to define a baseline against which all disaster impacts could be compared. If a catastrophic disaster was to occur in the Planning Area, this section describes significant assets at risk in the Planning Area. Data used in this baseline assessment included: Total assets at risk; Sacramento County 4-193 Local Hazard Mitigation Plan Update December 2016 Critical facility inventory; Cultural, historical, and natural resources; and Growth and development trends. Total Assets at Risk The total assets at risk for Sacramento County is intended to capture the values associated with assessed assets located within the Sacramento County Planning Area. The 2016 GIS parcel layer, obtained from Sacramento County GIS and the 2015 Sacramento County Assessor’s Data – Certified Roll obtained from the County Assessor was used for this analysis. This data provided by Sacramento County represents best available data. Understanding the total assessed value of Sacramento County is a starting point to understanding the overall value of the Planning Area. When the total assessed values are combined with potential values associated with other community assets such as natural resources, cultural and historic resources, and public and private critical infrastructure, the big picture emerges as to what is potentially at risk and vulnerable to the damaging effects of natural hazards within the County Planning Area. Data Limitations & Notations Although based on best available data, the resulting information should only be used as an initial guide to overall values in the County. The County GIS parcel data contained 445,518 records and the County Assessor data contained 474,727 records. Both tables were joined together within the GIS environment, and a total of 444,089 records were linked. In some cases, it is possible that the Assessor data may contain duplicate records under one parcel identification number (APN). For the purpose of this study, 1 Assessor record corresponds to 1 GIS parcel. In total, there were 2,429 Assessor records that are not included in the Total Assets at Risk Tables detailed below and are also excluded from further hazard analyses as these records were not matched to the GIS records. In the event of a disaster, infrastructure and improvements are at the greatest risk of damage. Depending on the type of hazard and resulting damages, the land itself may not suffer a significant loss. For that reason, the values of infrastructure and improvements are of greatest concern. As such, it is critical to note a specific limitation to the assessed values data within the County, due to Proposition 13. Instead of adjusting property values annually, no adjustments are made until a property transfer occurs. As a result, overall property value information is most likely low and may not reflect current market or true potential loss values for properties within the County. Methodology Sacramento County’s 2015 Assessor Data provided by the County Assessor’s office, were used as the basis for the inventory of assessed values for both improved and unimproved parcels within the Planning Area. The source GIS parcel data used for this analysis provides the land and improved values assessed for each parcel, along with information about property use and ownership. The jurisdiction in which the parcel resides is also indicated in the source parcel data. Sacramento County 4-194 Local Hazard Mitigation Plan Update December 2016 Sacramento County Use Codes provide detailed descriptive information about how each property is generally used, such as irrigated farm, apartment, restaurant, or industrial warehouse. The many use codes were logically grouped into the following simplified categories for the hazards analysis: Agricultural, Care/Health, Church/Welfare, Industrial, Miscellaneous, Office, Public/Utilities, Recreational, Residential, Retail/Commercial, Vacant, and No Data. Once Use Codes were grouped into categories, the number of total and improved parcels were inventoried by jurisdiction. Values associated with land, and improved structure values were identified and summed in order to determine total values at risk in the Sacramento County Planning Area, and specific to each jurisdiction. Together, the Land Value and Improved Structure Value make up the total value associated with each identified parcel or asset. Improved parcel counts were based on the assumption that a parcel was improved if a structure value was present. The Sacramento County Planning Area has a total land value of $38.87 billion, improved structure value of $90.9 billion, and a total value of $ $129.7 billion. Unincorporated Sacramento County has 157,818 improved parcels with a total value (both land and improvements)