This is a point feature class of all groundwater elevation monitoring stations (wells) maintained in the California Department of Water Resources’ (hereafter the Department) Enterprise Water Management database. Individual station information comes from a wide variety of sources, including and local and federal agencies, that conduct groundwater elevation monitoring within the state of California.

This dataset depicts change in groundwater level at selected monitoring locations (wells) between two specified years, by season. Change values represent change in groundwater level (elevation) by year and season (fall or spring). Other information on the monitoring location is also included. Positive values indicate groundwater has risen (groundwater surface elevation has increased) from the early year to the late year, while negative values indicate groundwater level surface has fallen (decreased in elevation ) from the early year to the late year. Water level monitoring locations and measurements used are selected based on measurement date and well construction information, where available, and approximate groundwater levels in the unconfined to uppermost semi-confined aquifers.

This dataset depicts change in groundwater level at selected monitoring locations (wells) between two specified years, by season. Change values represent change in groundwater level (elevation) by year and season (fall or spring). Other information on the monitoring location is also included. Positive values indicate groundwater has risen (groundwater surface elevation has increased) from the early year to the late year, while negative values indicate groundwater level surface has fallen (decreased in elevation ) from the early year to the late year. Water level monitoring locations and measurements used are selected based on measurement date and well construction information, where available, and approximate groundwater levels in the unconfined to uppermost semi-confined aquifers. For more information on this service, please contact gis@water.ca.gov

This dataset depicts contours of estimated change in groundwater piezometric surfaces in the unconfined or uppermost semi-confined aquifers, between two specified years, by season. Contours represent change in groundwater level (elevation) by year and season (fall or spring). The contour interval is 10 ft. The contours represent lines of equal change in groundwater level surface. Positive values indicate groundwater has risen (groundwater surface elevation has increased) from the early year to the late year, while negative values indicate groundwater level surface has fallen (decreased in elevation ) from the early year to the late year. For 'Elevation' type contours, contours represent lines of equal elevation of the estimated groundwater level surface above mean sea level. Higher contour values indicate higher elevations of the estimated groundwater level. Water level measurements used for contouring are selected based on measurement date and well construction information, where available, and approximate groundwater levels in the unconfined to uppermost semi-confined aquifers.

This dataset depicts contours of estimated change in groundwater piezometric surfaces in the unconfined or uppermost semi-confined aquifers, between two specified years, by season. Contours represent change in groundwater level (depth) by year and season (fall or spring). The contour interval is 10 ft.

This dataset depicts contours of estimated change in groundwater piezometric surfaces in the unconfined or uppermost semi-confined aquifers, between two specified years, by season. Contours represent change in groundwater level (elevation) by year and season (fall or spring). The contour interval is 10 ft.

,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

This dataset depicts groundwater level (expressed as depth below ground surface) at selected monitoring locations (wells), by season and year. Other information on the monitoring location is also included. Water level monitoring locations and measurements used are selected based on measurement date and well construction information, where available, and approximate groundwater levels in the unconfined to uppermost semi-confined aquifers.

,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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