Water Shortage Vulnerability Technical Methods

Technical methods used to compile data for and calculate the Social Vulnerability Index by Block Group for California. The American Community Survey (ACS) 2017-2021 estimates were used because these are currently considered the best available to date.

This document presents the 2023 update methods to the Water Shortage Vulnerability scoring for rural communities, including the indicators, datasets, methods used, and a statistical summary of results. This is an update to the scoring and tool that the California Department of Water Resources (DWR) developed in collaboration with the County Drought Advisory Group (CDAG) and submitted to the Legislature in April 2021 (DWR 2021). This document presents the first update to the construction of the indicators and scoring for the state small water systems, rural communities, domestic wells and other self-supplied residents, per California Water Code Section 10609.80(a)(2)(B-C). Data used in the 2023 update and tool are updated as of the preparation of this analysis in October 2022.

This document presents the Small Water Systems 2023 update to the Water Shortage Vulnerability scoring, including the indicators, datasets, and methods used, and a statistical summary of results. Data is available in multiple formats here: https://data.cnra.ca.gov/dataset/i07-water-shortage-vulnerability-small-water-systems. An interactive dashboard displaying the data is here: https://tableau.cnra.ca.gov/t/DWR_IntegratedDataAnalysisBranch/views/Book2/Dashboard1?%3Aembed=y&%3Aiid=1&%3AisGuestRedirectFromVizportal=y. This is an update to the scoring and tool that the California Department of Water Resources (DWR) submitted to the legislature in April 2021, developed in collaboration with the County Drought Advisory Group (CDAG).

This is a 2024 version of the technical methods for the vulnerability analysis for small water systems and separately for domestic wells and state smalls, as required by Senate Bill 552. Published December 15, 2024.