This dataset represents a water shortage social vulnerability analysis
performed by DWR using Census 2020 block groups as the unit of analysis.
This feature class includes water shortage social vulnerability
indicators and scores from an analysis done by CA Department of Water
Resources, joined to the 2020 Census Block Groups. Most of the
indicators were pulled from the ACS (American Communities Survey). These
indicators were joined to the block groups to represent a spatial
analysis of the social vulnerability of communities to water shortages.
The goal of this data is to provide a spatial representation of social
and economic factors that can affect water shortage vulnerability in the
state of California. Model indicators included in the attribute table
are percent of the population 65 and older, percent of households with
no vehicles, percent of population 25 and older without a high school
diploma. Please note that all of these model indicators are estimated
values pulled from the ACS (American Communities Survey). All model
indicators are added together using sum-rank methods outlined in the
Drought and Water Shortage Risk Scoring: California's Domestic Wells and
State Smalls Systems document and CDC standards for sum-rank methods.
This data is for the 2022 analysis using 2015-2019 ACS estimates and
2020 Census block groups. From the draft Drought and Water Shortage
Vulnerability Scoring document: “Water Code Division 6 Part 2.55 Section
8 Chapter 10 (Assembly Bill 1668) effectively requires California
Department of Water Resources (DWR), in consultation with other agencies
and an advisory group, to identify small water suppliers and “rural
communities” that are at risk of drought and water shortage. Following
legislation passed in 2021 and signed by Governor Gavin Newsom, the
Water Code Division 6, Section 10609.50 through 10609.80 (Senate Bill
552 of 2021) effectively requires the California Department of Water
Resources to update the scoring and tool periodically in partnership
with the State Water Board and other state agencies. This document
describes the indicators, datasets, and methods used to construct this
deliverable. "
A spatial analysis was performed on the 2020 Census Block Groups,
modified PLSS sections, and small water system service areas using a
variety of input datasets related to drought vulnerability and water
shortage risk. These indicator values were subsequently rescaled and
summed for a final physical vulnerability score for the sections and
small water system service areas. The 2020 Census Block Groups were
joined with ACS data to represent the social vulnerability of
communities, which is relevant to drought risk tolerance and resources.
These three feature datasets contain the units of analysis (modified
PLSS sections, block groups, small water systems service areas) with the
model indicators for vulnerability in the attribute table. Model
indicators are calculated for each unit of analysis according to the
Vulnerability Scoring documents provided by Julia Ekstrom (Division of
Regional Assistance). All three feature classes are DWR analysis zones
that are based off existing GIS datasets. The spatial data for the
sections feature class is extracted from the Well Completion Reports
PLSS sections to be aligned with the work and analysis that SGMA is
doing. These are not true PLSS sections, but a version of the projected
section lines in areas where there are gaps in PLSS. The spatial data
for the Census block group feature class is downloaded from the Census.
ACS (American Communities Survey) data is joined by block group, and
statistics calculated by DWR have been added to the attribute table. The
spatial data for the small water systems feature class was extracted
from the State Water Resources Control Board (SWRCB) SABL dataset, using
a definition query to filter for active water systems with 3000
connections or less. None of these datasets are intended to be the
authoritative datasets for representing PLSS sections, Census block
groups, or water service areas. The spatial data of these feature
classes is used as units of analysis for the spatial analysis performed
by DWR. These datasets are intended to be authoritative datasets of the
scoring tools required from DWR according to Senate Bill 552. Please
refer to the Drought and Water Shortage Vulnerability Scoring:
California's Domestic Wells and State Smalls Systems documentation for
more information on indicators and scoring. These estimated indicator
scores may sometimes be calculated in several different ways, or may
have been calculated from data that has since be updated. The associated
data are considered DWR enterprise GIS data, which meet all appropriate
requirements of the DWR Spatial Data Standards, specifically the DWR
Spatial Data Standard version 3.4, dated September 14, 2022. DWR makes
no warranties or guarantees — either expressed or implied— as to the
completeness, accuracy, or correctness of the data. DWR neither accepts
nor assumes liability arising from or for any incorrect, incomplete, or
misleading subject data. Comments, problems, improvements, updates, or
suggestions should be forwarded to [email protected].
