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.

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One foot contours developed from Delta LIDAR. LIDAR was developed under a contract between California DWR and URS Corporation (DRMS contract), with Fugro EarthData as lead LIDAR survey contractor. Flights were conducted in 2007 with 9% reflown in 2008. Final products delivered to DWR in 2009. Survey points of accuracy theoretically capable of supporting 1 foot contours. Using processed bare earth point data, Fugro EarthData generated/supplied these contours in raw and smoothed format, and the feature class here are smoothed contours. These data are public domain. Additional information can be obtained from California DWR.

This data is prepared by Land IQ, LLC and provided to the California Department of Water Resources (DWR) and other resource agencies involved in work and planning efforts across the state for current land use information. This dataset is meant to provide information for resource planning and assessments across multiple agencies and serves as a consistent base layer for a broad array of potential users and multiple end uses. This dataset presents the 2014 agricultural land use, managed wetlands, and urban boundaries for all 58 counties in California. This data is prepared by Land IQ, LLC and provided to the California Department of Water Resources (DWR) and other resource agencies involved in work and planning efforts across the state for current land use information. Delineated from 2014 NAIP Imagery. The data are derived from a combination of remote sensing and agronomic analysis and ground verification.

,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

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,The IRWM web based DAC mapping tool uses this GIS layer. Created by joining ACS 2019-2023 5 year estimates to the 2020 Census Counties feature class. The TIGER/Line Files are shapefiles and related database files (.dbf) that are an extract of selected geographic and cartographic information from the U.S. Census Bureau's Master Address File / Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) Database (MTDB). The MTDB represents a seamless national file with no overlaps or gaps between parts, however, each TIGER/Line File is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. The primary legal divisions of most States are termed counties. In Louisiana, these divisions are known as parishes. In Alaska, which has no counties, the equivalent entities are the organized boroughs, city and boroughs, and municipalities, and for the unorganized area, census areas. The latter are delineated cooperatively for statistical purposes by the State of Alaska and the Census Bureau. In four States (Maryland, Missouri, Nevada, and Virginia), there are one or more incorporated places that are independent of any county organization and thus constitute primary divisions of their States. These incorporated places are known as independent cities and are treated as equivalent entities for purposes of data presentation. The District of Columbia and Guam have no primary divisions, and each area is considered an equivalent entity for purposes of data presentation. The Census Bureau treats the following entities as equivalents of counties for purposes of data presentation: Municipios in Puerto Rico, Districts and Islands in American Samoa, Municipalities in the Commonwealth of the Northern Mariana Islands, and Islands in the U.S. Virgin Islands. The entire area of the United States, Puerto Rico, and the Island Areas is covered by counties or equivalent entities. The 2020 Census boundaries for counties and equivalent entities are as of April 1, 2020, primarily as reported through the Census Bureau's Boundary and Annexation Survey (BAS).,

This is the official dataset of CADWR for determining agricultural land use and irrigated acres. The purpose is provide information for resource planning and assessments across multiple agencies. Delta Landuse dataset for the extent of Delta Boundary. Delineated on Pleiades Image from July 13-14, 2015. The dataset is a comprehensive landuse for the period of July 13-14 2015 and also contains information on agricultural classes for spring 2015. Major assumption of this dataset is that the native vegetation is grouped into 5 level 2 categories and are grouped into 3 DWR native categories.

,This point dataset represents the location of gaging stations in the Sacramento-San Joaquin Delta and Suisun Marsh that have historic and statistical hydrologic data, specifically various river stage data. Stages are given in NAVD88, units feet. Specific stages are given for peak stages, 100-year stages produced under 2 separate US Army Corps of Engineers hydrology reports from 1976 and 1992, the year of previous peak stages cited by the 1976 and 1992 reports, and approximate typical tidal values as approximately estimated based on long term data records. This 2023 version of this datset replaces the prior 2020 version, and should be used as a complete replacement. The underlying analyses did not change, but the USACE peak observed stage field names from the prior version were corrected and supplemental USACE 50- and 100-year stages were added accordingly. In addition, the vertical datum conversion used at specific gages was added. The vertical datum conversion is based on DWR survey and North Central Regional Office information that is maintained for each gage station. The stage data was compiled by Karen Tolentino, engineer with Delta Levees, and by Joel Dudas, Senior Engineer in DWR's Division of Engineering, based on a wide variety of sources, including the HYDSTRA database, various historic bulletins, raw data, station histories, and other information provided by DWR's North Central Region Office, USGS, and other misc sources. They also adjusted all data to approximate NAVD88-related stages. Observed data periods of record varied widely by station, but go back as far as 1905. All peak values were derived from start of records until up to May, 2017.,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 3.5, dated April 12, 2023. 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 GIS@water.ca.gov.,