Description: "Vulnerability" was assessed using 15 indicators at the census block group level. Thirteen indicators were assigned a score of either 0 (does not meet the vulnerability threshold) or 1 (meets the vulnerability threshold). Where multiple datasets contributed to a single indicator, a block group was considered vulnerable if it met the threshold in any of the contributing datasets. Two indicators, mobile home residents and migrant housing residents, were assigned a weight of 2. This additional weighting was applied because these populations may be underrepresented in census-based datasets, are more likely to experience multiple overlapping vulnerabilities, and, in the case of mobile homes, may face greater flood-related structural risk.For each census block group intersecting the SPFC Planning Area, the weighted indicator scores were summed to calculate a final Vulnerability Score ranging from 0 to 17. The resulting scores were ranked across all 1,108 census block groups within the SPFC Planning Area and converted to percentile ranks to reflect each block group's relative vulnerability compared to all others. Vulnerability categories (Low, Medium, High, and Highest) were then assigned based on percentile thresholds, with the methodology intended to identify and prioritize the most vulnerable communities for flood risk planning and resource allocation.Sources, approach and analysis are documented for each indicator in the respective field descriptions. Wherever data were available at block group scale, data were filtered and scored at that scale. For several metrics, data were available only at Census Tract scale. In those cases, the census tract score was distributed across all block groups within that tract.Approach for Migrant Housing:"Census tracts were classified as 'vulnerable' for indicator 'migrant housing resident' if that tract contained a government-run or overseen migrant housing facility. Tract rating was distributed across block groups within that tract. All FOIA data were excluded entirely from this analysis."Process: County by county search of California and utilizing only those locations listed as "farmworker" housing. MFH Rentals (USDA RD) – State of California Owned or Overseen.Process: Searched for and validated each location listed on Office of Migrant Services (CA Dept of Housing and Community Development) map.Data Source websites accessed 2025 and 2026:Migrant Housing Program | Modoc County, CANEWELL MIGRANT CENTER — USDA Rural Development Low Income Housing in Newell.California Staff Directory • Migrant Farm Housing (Colusa County, Williams)https://www.regionalha.org/properties/yuba-city-migrant-housing-center(Sutter County, Yuba City)https://www.ych.ca.gov/about-us/(Yolo & Solano Counties) – includes: Davis Migrant Center, Dixon Migrant Center, and Madison Migrant Center.https://hacsj.org/housing/farm-labor-housing/(San Joaquin County) – includes: Harney Lane Migrant Center, Joseph J. Artesi II Migrant Center, and Joseph J. Artesi III Migrant Center.https://stanregionalha.org/migrant-farmworker-housing/(Stanislaus County) – includes: Empire Migrant Center, Westley Migrant Center, and Patterson Migrant Center.https://www.merced-pha.com/migrant.html(Merced County) – includes: Atwater Migrant Center, Merced Migrant Center, Los Banos Migrant Center, and Planada Migrant Center.https://maderaha.org/housing-programs/pomona-ranch-housing-center/(City of Madera) – includes: Pomona Ranch Housing Center.https://fresnohousing.org/properties/parlier-migrant-center/(Fresno County) – includes: Parlier Migrant Center.https://hhsa.sanbenitocountyca.gov/community-service-workforce-development/migrant-center/(San Benito County) – includes: Hollister Migrant Housing Center.https://stanregionalha.org/migrant-farmworker-housing/(Santa Clara County) – includes: Arturo Ochoa Migrant Center (AOMC).https://stanregionalha.org/migrant-farmworker-housing/(Santa Cruz County) – includes: Buena Vista Migrant Center.https://www.hamonterey.org/migrant-and-permanent-farm-worker-housing/(Monterey County) – includes: King City Migrant Center.
Description: "Vulnerability" was assessed using 15 indicators at the census block group level. Thirteen indicators were assigned a score of either 0 (does not meet the vulnerability threshold) or 1 (meets the vulnerability threshold). Where multiple datasets contributed to a single indicator, a block group was considered vulnerable if it met the threshold in any of the contributing datasets. Two indicators, mobile home residents and migrant housing residents, were assigned a weight of 2. This additional weighting was applied because these populations may be underrepresented in census-based datasets, are more likely to experience multiple overlapping vulnerabilities, and, in the case of mobile homes, may face greater flood-related structural risk.For each census block group intersecting the SPFC Planning Area, the weighted indicator scores were summed to calculate a final Vulnerability Score ranging from 0 to 17. The resulting scores were ranked across all 1,108 census block groups within the SPFC Planning Area and converted to percentile ranks to reflect each block group's relative vulnerability compared to all others. Vulnerability categories (Low, Medium, High, and Highest) were then assigned based on percentile thresholds, with the methodology intended to identify and prioritize the most vulnerable communities for flood risk planning and resource allocation.Sources, approach and analysis are documented for each indicator in the respective field descriptions. Wherever data were available at block group scale, data were filtered and scored at that scale. For several metrics, data were available only at Census Tract scale. In those cases, the census tract score was distributed across all block groups within that tract.Approach for Migrant Housing:"Census tracts were classified as 'vulnerable' for indicator 'migrant housing resident' if that tract contained a government-run or overseen migrant housing facility. Tract rating was distributed across block groups within that tract. All FOIA data were excluded entirely from this analysis."Process: County by county search of California and utilizing only those locations listed as "farmworker" housing. MFH Rentals (USDA RD) – State of California Owned or Overseen.Process: Searched for and validated each location listed on Office of Migrant Services (CA Dept of Housing and Community Development) map.Data Source websites accessed 2025 and 2026:Migrant Housing Program | Modoc County, CANEWELL MIGRANT CENTER — USDA Rural Development Low Income Housing in Newell.California Staff Directory • Migrant Farm Housing (Colusa County, Williams)https://www.regionalha.org/properties/yuba-city-migrant-housing-center(Sutter County, Yuba City)https://www.ych.ca.gov/about-us/(Yolo & Solano Counties) – includes: Davis Migrant Center, Dixon Migrant Center, and Madison Migrant Center.https://hacsj.org/housing/farm-labor-housing/(San Joaquin County) – includes: Harney Lane Migrant Center, Joseph J. Artesi II Migrant Center, and Joseph J. Artesi III Migrant Center.https://stanregionalha.org/migrant-farmworker-housing/(Stanislaus County) – includes: Empire Migrant Center, Westley Migrant Center, and Patterson Migrant Center.https://www.merced-pha.com/migrant.html(Merced County) – includes: Atwater Migrant Center, Merced Migrant Center, Los Banos Migrant Center, and Planada Migrant Center.https://maderaha.org/housing-programs/pomona-ranch-housing-center/(City of Madera) – includes: Pomona Ranch Housing Center.https://fresnohousing.org/properties/parlier-migrant-center/(Fresno County) – includes: Parlier Migrant Center.https://hhsa.sanbenitocountyca.gov/community-service-workforce-development/migrant-center/(San Benito County) – includes: Hollister Migrant Housing Center.https://stanregionalha.org/migrant-farmworker-housing/(Santa Clara County) – includes: Arturo Ochoa Migrant Center (AOMC).https://stanregionalha.org/migrant-farmworker-housing/(Santa Cruz County) – includes: Buena Vista Migrant Center.https://www.hamonterey.org/migrant-and-permanent-farm-worker-housing/(Monterey County) – includes: King City Migrant Center.