This dataset represents polygon boundaries of all public water agencies in California including public water systems, agricultural water districts, urban water districts, Federal and State water contractors, wholesalers, retailers, and other public or private utilities that deliver water to the end user.

California Water District Boundaries
from Open Data Stackexchange:
http://opendata.stackexchange.com/questions/5157/california-water-district-boundaries
Provided in multiple GIS formats
Private Water District boundaries are areas where private contracts provide water to the district in California. This database is designed as a regions polygon database and is updated when sufficient number of changes have occured to warrant an update. Updates are determined by the needs of the local office. Separate databases are used for maintenance purposes. Boundaries are continually being updated as changes are identified by the Water Districts. The boundaries are not current for all Water http://catalog.data.gov/dataset/private-water-districts
State Water Districts
State Water Project District boundaries are areas where state contracts provide water to the district in California. This database is designed as a regions polygon database and is updated when sufficient number of changes have occured to warrant an update. Updates are determined by the needs of the local office. Separate databases are used for maintenance purposes. Boundaries are continually being updated as changes are identified by the Water Districts. The boundaries are not current for all Wa ...
that is not a typo, its the direct text http://catalog.data.gov/dataset/state-water-districts

https://web.archive.org/web/*/http://projects.atlas.ca.gov/frs/download.php/26/usbr_wat_dist_priv.zip
https://web.archive.org/web/%2a/http://projects.atlas.ca.gov/frs/download.php/245/usbr_wat_dist_state_2003_03_25.zip
gist: https://gist.github.com/pdbartsch/07277a0645fb2df9f729

Private Water District boundaries are areas where private contracts provide water to the district in California. This database is designed as a regions polygon database and is updated when sufficient number of changes have occured to warrant an update. Updates are determined by the needs of the local office. Separate databases are used for maintenance purposes. Boundaries are continually being updated as changes are identified by the Water Districts. The boundaries are not current for all Water

Geospatial data about Placer County, California Water Districts. Export to CAD, GIS, PDF, CSV and access via API.

Polygonal representation of the California Water Service District area.

This dataset is intended for researchers, students, and policy makers for reference and mapping purposes, and may be used for basic applications such as viewing, querying, and map output production, or to provide a basemap to support graphical overlays and analysis with other spatial data.

San Joaquin County, CA - Water Districts

© San Joaquin County GIS

Community Service Districts

Polygons representing water districts in Placer County California.

This polygon shapefile depicts the boundaries of water districts in the County of San Mateo, California. A water district is a special district given the task of supplying water and sewer needs to a community. This layer is part of a collection of GIS data for San Mateo County, California.

Data are a graphic representation of water district boundaries in Marin County, California.

Community Service Districts

This feature class contains features representing the Metropolitan Water District of Southern California District portion within Ventura County. Boundary matches the boundary of Calleguas Municipal Water District as of 3/15/2023.Provides wholesale water from the State Water Project to cities and other districts for the entire area south of the Santa Clara River.

Description for i03_DAU_county_cnty2018 is as follows:

Detailed Analysis Unit-(DAU) Convergence via County Boundary cnty18_1 for Cal-Fire, (See metadata for CAL-FIRE cnty18_1), State of California.

The existing DAU boundaries were aligned with cnty18_1 feature class.

Originally a collaboration by Department of Water Resources, Region Office personnel, Michael L. Serna, NRO, Jason Harbaugh - NCRO, Cynthia Moffett - SCRO and Robert Fastenau - SRO with the final merge of all data into a cohesive feature class to create i03_DAU_COUNTY_cnty24k09 alignment which has been updated to create i03_DAU_COUNTY_cnty18_1.

This version was derived from a preexisting “dau_v2_105, 27, i03_DAU_COUNTY_cnty24k09” Detailed Analysis Unit feature class's and aligned with Cal-Fire's 2018 boundary.

Manmade structures such as piers and breakers, small islands and coastal rocks have been removed from this version. Inlets waters are listed on the coast only.

These features are reachable by County\DAU. This allows the county boundaries, the DAU boundaries and the State of California Boundary to match Cal-Fire cnty18_1.

DAU Background

The first investigation of California's water resources began in 1873 when President Ulysses S. Grant commissioned an investigation by Colonel B. S. Alexander of the U.S. Army Corps of Engineers. The state followed with its own study in 1878 when the State Engineer's office was created and filled by William Hammond Hall. The concept of a statewide water development project was first raised in 1919 by Lt. Robert B. Marshall of the U.S. Geological Survey.

In 1931, State Engineer Edward Hyatt introduced a report identifying the facilities required and the economic means to accomplish a north-to-south water transfer. Called the "State Water Plan", the report took nine years to prepare. To implement the plan, the Legislature passed the Central Valley Act of 1933, which authorized the project. Due to lack of funds, the federal government took over the CVP as a public works project to provide jobs and its construction began in 1935.

In 1945, the California Legislature authorized an investigation of statewide water resources and in 1947, the California Legislature requested that an investigation be conducted of the water resources as well as present and future water needs for all hydrologic regions in the State. Accordingly, DWR and its predecessor agencies began to collect the urban and agricultural land use and water use data that serve as the basis for the computations of current and projected water uses.

The work, conducted by the Division of Water Resources (DWR’s predecessor) under the Department of Public Works, led to the publication of three important bulletins: Bulletin 1 (1951), "Water Resources of California," a collection of data on precipitation, unimpaired stream flows, flood flows and frequency, and water quality statewide; Bulletin 2 (1955), "Water Utilization and Requirements of California," estimates of water uses and forecasts of "ultimate" water needs; and Bulletin 3 (1957), "The California Water Plan," plans for full practical development of California’s water resources, both by local projects and a major State project to meet the State's ultimate needs. (See brief addendum below* “The Development of Boundaries for Hydrologic Studies for the Sacramento Valley Region”)

DWR subdivided California into study areas for planning purposes. The largest study areas are the ten hydrologic regions (HR), corresponding to the State’s major drainage basins. The next levels of delineation are the Planning Areas (PA), which in turn are composed of multiple detailed analysis units (DAU). The DAUs are often split by county boundaries, so are the smallest study areas used by DWR.

The DAU/counties are used for estimating water demand by agricultural crops and other surfaces for water resources planning. Under current guidelines, each DAU/County has multiple crop and land-use categories. Many planning studies begin at the DAU or PA level, and the results are aggregated into hydrologic regions for presentation.

The Geographic Information Systems (GIS) Unit falls under the purview of the County of Santa Cruz Information Services Department. The GIS Unit serves all County departments and external customers and provides data on land, features and people of Santa Cruz County. Santa Cruz County encompasses 4 cities and approximately 265,000 people. This coverage can be used for basic applications such as viewing, querying and map output production, or to provide a basemap to support graphical overlays and analyses of geospatial data.

This polygon shapefile contains the boundaries for water districts in Monterey County, California. Water districts are responsible for water distribution systems that provide services the county. This layer is part of a collection of GIS data for Monterey County in California.

Alameda County Water District with district boundary. Boundaries represent voting districts (i.e., district designation for each address) and therefore may align with parcel boundaries in cases where parcels (and sometimes residences) are divided by the true city/district boundary.

State Water Project District boundaries are areas where state contracts provide water to the district in California. This database is designed as a regions polygon database and is updated when sufficient number of changes have occurred to warrant an update. Updates are determined by the needs of the local office. Separate databases are used for maintenance purposes. Boundaries are continually being updated as changes are identified by the Water Districts. The boundaries are not current for all Water Districts found in the database at the same time due to the update methods employed. There may be conflicts in the boundaries between districts due to the time of update and review process associated with each Water District. Other problems may be associated with Water District name changes that have not been updated and possibly new Water Districts not being included due to lack of information. This database represents the most current and accurate understanding of the boundary location and current name of the Water Districts.

A source water assessment identifies the vulnerability of the drinking water supply to contamination from typical human activities. The assessments are intended to facilitate and provide the basic information necessary for a local community to develop a program to protect the drinking water supply.

A source water assessment identifies the vulnerability of the drinking water supply to contamination from typical human activities. The assessments are intended to facilitate and provide the basic information necessary for a local community to develop a program to protect the drinking water supply.