This is the official GIS layer representing the boundary of Santa Clara County as an outline.

This resource is a member of a series. The TIGER/Line shapefiles and related database files (.dbf) 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) System (MTS). The MTS represents a seamless national file with no overlaps or gaps between parts, however, each TIGER/Line shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. The All Roads shapefile includes all features within the MTS Super Class "Road/Path Features" distinguished where the MAF/TIGER Feature Classification Code (MTFCC) for the feature in the MTS that begins with "S". This includes all primary, secondary, local neighborhood, and rural roads, city streets, vehicular trails (4wd), ramps, service drives, alleys, parking lot roads, private roads for service vehicles (logging, oil fields, ranches, etc.), bike paths or trails, bridle/horse paths, walkways/pedestrian trails, and stairways.

This polyline shapefile depicts the administrative boundary for the County of Santa Clara, California. This layer is part of a collection of GIS data for Santa Clara County, California.

The TIGER/Line shapefiles and related database files (.dbf) 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) System (MTS). The MTS represents a seamless national file with no overlaps or gaps between parts, however, each TIGER/Line shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. The Address Range Features shapefile contains the geospatial edge geometry and attributes of all unsuppressed address ranges for a county or county equivalent area. The term "address range" refers to the collection of all possible structure numbers from the first structure number to the last structure number and all numbers of a specified parity in between along an edge side relative to the direction in which the edge is coded. Single-address address ranges have been suppressed to maintain the confidentiality of the addresses they describe. Multiple coincident address range feature edge records are represented in the shapefile if more than one left or right address ranges are associated to the edge. This shapefile contains a record for each address range to street name combination. Address ranges associated to more than one street name are also represented by multiple coincident address range feature edge records. Note that this shapefile includes all unsuppressed address ranges compared to the All Lines shapefile (edges.shp) which only includes the most inclusive address range associated with each side of a street edge. The TIGER/Line shapefiles contain potential address ranges, not individual addresses. The address ranges in the TIGER/Line shapefiles are potential ranges that include the full range of possible structure numbers even though the actual structures may not exist.

The TIGER/Line shapefiles and related database files (.dbf) 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 shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. Face refers to the areal (polygon) topological primitives that make up MTDB. A face is bounded by one or more edges; its boundary includes only the edges that separate it from other faces, not any interior edges contained within the area of the face. The Topological Faces Shapefile contains the attributes of each topological primitive face. Each face has a unique topological face identifier (TFID) value. Each face in the shapefile includes the key geographic area codes for all geographic areas for which the Census Bureau tabulates data for both the 2020 Census and the annual estimates and surveys. The geometries of each of these geographic areas can then be built by dissolving the face geometries on the appropriate key geographic area codes in the Topological Faces Shapefile.

Census blockgroup geometry within Santa Clara County from the 2010 Census Tiger shapefiles. Feature class derived from Tiger line shapefile of 2010 census blockgroups for Santa Clara County and geographic identifier table, G001. Some attribute names may be when exporting as shapefile due to 10 character limitation of shapefile attribute names. THE GIS DATA IS PROVIDED "AS IS". THE COUNTY MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION, ANY IMPLIED WARRANTIES OR MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE, REGARDING THE ACCURACY, COMPLETENESS, VALUE, QUALITY, VALIDITY, MERCHANTABILITY, SUITABILITY, AND CONDITION, OF THE GIS DATA. USER'S OF COUNTY'S GIS DATA ARE HEREBY NOTIFIED THAT CURRENT PUBLIC PRIMARY INFORMATION SOURCES SHOULD BE CONSULTED FOR VERIFICATION OF THE DATA AND INFORMATION CONTAINED HEREIN. SINCE THE GIS DATA IS DYNAMIC, IT WILL BY ITS NATURE BE INCONSISTENT WITH THE OFFICIAL COUNTY DATA. ANY USE OF COUNTY'S GIS DATA WITHOUT CONSULTING OFFICIAL PUBLIC RECORDS FOR VERIFICATION IS DONE EXCLUSIVELY AT THE RISK OF THE PARTY MAKING SUCH USE.

Splitgraph serves as an HTTP API that lets you run SQL queries directly on this data to power Web applications. For example:

See the Splitgraph documentation for more information.

The TIGER/Line shapefiles and related database files (.dbf) 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) System (MTS). The MTS represents a seamless national file with no overlaps or gaps between parts, however, each TIGER/Line shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. Edges refer to the linear topological primitives that make up the MTS. The All Lines shapefile contains linear features such as roads, railroads, and hydrography. Additional attribute data associated with the linear features found in the All Lines shapefile are available in relationship (.dbf) files that users must download separately. The All Lines shapefile contains the geometry and attributes of each topological primitive edge. Each edge has a unique TIGER/Line identifier (TLID) value.

The TIGER/Line shapefiles and related database files (.dbf) 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) System (MTS). The MTS represents a seamless national file with no overlaps or gaps between parts, however, each TIGER/Line shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. Linear water features include single-line drainage water features and artificial path features that run through double-line drainage features such as rivers and streams and serve as a linear representation of these features. The artificial path features may correspond to those in the U.S. Geological Survey National Hydrographic Dataset (NHD). However, in many cases the features do not match NHD equivalent features and will not carry the NHD metadata codes. These features have a MAF/TIGER Feature Classification Code (MTFCC) beginning with an "H" to indicate the super class of hydrographic features.

The TIGER/Line shapefiles and related database files (.dbf) 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 filewith no overlaps or gaps between parts, however, each TIGER/Line shapefile is designed to stand alone as an independentdata set, or they can be combined to cover the entire nation. Linear Water Features includes single-line drainage water features and artificial path features that run through double-line drainage features such as rivers and streams, and serve as a linear representation of these features. The artificial path features may correspond to those in the USGS National Hydrographic Dataset (NHD). However, in many cases the features do not match NHD equivalent feature and will not carry the NHD metadata codes. These features have a MAF/TIGER Feature Classification Code (MTFCC) beginning with an "H" to indicate the super class of Hydrographic Features.

The TIGER/Line shapefiles and related database files (.dbf) 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 shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. Face refers to the areal (polygon) topological primitives that make up MTDB. A face is bounded by one or more edges; its boundary includes only the edges that separate it from other faces, not any interior edges contained within the area of the face. The Topological Faces Shapefile contains the attributes of each topological primitive face. Each face has a unique topological face identifier (TFID) value. Each face in the shapefile includes the key geographic area codes for all geographic areas for which the Census Bureau tabulates data for both the 2020 Census and the annual estimates and surveys. The geometries of each of these geographic areas can then be built by dissolving the face geometries on the appropriate key geographic area codes in the Topological Faces Shapefile.

The TIGER/Line shapefiles and related database files (.dbf) 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) System (MTS). The MTS represents a seamless national file with no overlaps or gaps between parts, however, each TIGER/Line shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. Face refers to the areal (polygon) topological primitives that make up the MTS. A face is bounded by one or more edges; its boundary includes only the edges that separate it from other faces, not any interior edges contained within the area of the face. The Topological Faces shapefile contains the attributes of each topological primitive face. Each face has a unique topological face identifier (TFID) value. Each face in the shapefile includes the key geographic area codes for all geographic areas for which the Census Bureau tabulates data for both the 2020 Census and the annual estimates and surveys. The geometries of each of these geographic areas can then be built by dissolving the face geometries on the appropriate key geographic area codes in the Topological Faces shapefile.

The TIGER/Line shapefiles and related database files (.dbf) 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) System (MTS). The MTS represents a seamless national file with no overlaps or gaps between parts, however, each TIGER/Line shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. The Census Bureau includes landmarks in the MTS for locating special features and to help enumerators during field operations. Some of the more common landmark types include airports, cemeteries, parks, schools, and churches and other religious institutions. The Census Bureau adds landmark features to MTS on an as-needed basis and does not ensure that all instances of a particular feature are included. The presence or absence of a landmark such as a hospital or prison does not mean that the living quarters associated with that landmark were geocoded to that census tabulation block or excluded from the census enumeration. The Area Landmark shapefile does not include military installations or water bodies because they appear in their own separate shapefiles, mil.shp and areawater.shp respectively.

The TIGER/Line shapefiles and related database files (.dbf) 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 filewith no overlaps or gaps between parts, however, each TIGER/Line shapefile is designed to stand alone as an independentdata set, or they can be combined to cover the entire nation. Linear Water Features includes single-line drainage water features and artificial path features that run through double-line drainage features such as rivers and streams, and serve as a linear representation of these features. The artificial path features may correspond to those in the USGS National Hydrographic Dataset (NHD). However, in many cases the features do not match NHD equivalent feature and will not carry the NHD metadata codes. These features have a MAF/TIGER Feature Classification Code (MTFCC) beginning with an "H" to indicate the super class of Hydrographic Features.

The TIGER/Line shapefiles and related database files (.dbf) 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 shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. The All Roads Shapefile includes all features within the MTDB Super Class "Road/Path Features" distinguished where the MAF/TIGER Feature Classification Code (MTFCC) for the feature in MTDB that begins with "S". This includes all primary, secondary, local neighborhood, and rural roads, city streets, vehicular trails (4wd), ramps, service drives, alleys, parking lot roads, private roads for service vehicles (logging, oil fields, ranches, etc.), bike paths or trails, bridle/horse paths, walkways/pedestrian trails, stairways, and winter trails.

The TIGER/Line shapefiles and related database files (.dbf) 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 shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. The Topological Faces / Area Hydrography Relationship File (FACESAH.dbf) contains a record for each face / area hydrography feature relationship. Face refers to the areal (polygon) topological primitives that make up MTDB. A face is bounded by one or more edges; its boundary includes only the edges that separate it from other faces, not any interior edges contained within the area of the face. The face to which a record in the Topological Faces / Area Hydrography Relationship File (FACESAH.dbf) applies can be determined by linking to the Topological Faces Shapefile (FACES.shp) using the permanent topological face identifier (TFID) attribute. The area hydrography feature to which a record in the Topological Faces / Area Hydrography Relationship File (FACESAH.dbf) applies can be determined by linking to the Area Hydrography Shapefile (AREAWATER.shp) using the area hydrography identifier (HYDROID) attribute. A face may be part of multiple area water features. An area water feature may consist of multiple faces.

The TIGER/Line shapefiles and related database files (.dbf) 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 filewith no overlaps or gaps between parts, however, each TIGER/Line shapefile is designed to stand alone as an independentdata set, or they can be combined to cover the entire nation. The Address Range / Feature Name Relationship File (ADDRFN.dbf) contains a record for each address range / linear feature name relationship. The purpose of this relationship file is to identify all street names associated with each address range. An edge can have several feature names; an address range located on an edge can be associated with one or any combination of the available feature names (an address range can be linked to multiple feature names). The address range is identified by the address range identifier (ARID) attribute that can be used to link to the Address Ranges Relationship File (ADDR.dbf). The linear feature name is identified by the linear feature identifier (LINEARID) attribute that can be used to link to the Feature Names Relationship File (FEATNAMES.dbf).

Descriptions of Metropolitan Transportation Commission's 34 Super DistrictsSuper District #1 - Greater Downtown San Francisco: This area, the northeastern quadrant of the city, is bounded by Van Ness Avenue on the west, 11th Street on the southwest, and Townsend Street on the south. This Super District includes the following neighborhoods and districts: Financial District, Union Square, Tenderloin, Civic Center, South of Market, South Park, Rincon Hill, Chinatown, Jackson Square, Telegraph Hill, North Beach, Nob Hill, Russian Hill, Polk Gulch and Fisherman's Wharf. Treasure Island and Yerba Buena Island are also part of Super District #1.Super District #2 - Richmond District: This area, the northwestern quadrant of the city, is bounded by Van Ness Avenue on the east, Market Street on the southeast, and 17th Street, Stanyan Street, and Lincoln Way on the south. Super District #2 includes the following neighborhoods and districts: the Presidio, the Western Addition District, the Marina, Cow Hollow, Pacific Heights, Cathedral Hill, Japantown, Hayes Valley, Duboce Triangle, the Haight-Ashbury, the Richmond District, Inner Richmond, Outer Richmond, Laurel Heights, Sea Cliff, and the Golden Gate Park.Super District #3 - Mission District: This area, the southeastern quadrant of the city, is bounded by Townsend Street, 11th Street, Market Street, 17th Street, Stanyan Street, and Lincoln Way on the northern boundary; 7th Avenue, Laguna Honda, Woodside Avenue, O'Shaughnessy Boulevard and other smaller streets (Juanita, Casita, El Verano, Ashton, Orizaba) on the western boundary; and by the San Mateo County line on the southern boundary. Super District #3 includes the following neighborhoods and districts: China Basin, Potrero Hill, Inner Mission, Outer Mission, Twin Peaks, Parnassus Heights, Dolores Heights, Castro, Eureka Valley, Noe Valley, Bernal Heights, Glen Park, Ingleside, Ocean View, the Excelsior, Crocker-Amazon, Visitacion Valley, Portola, Bayview, and Hunters Point.Super District #4 - Sunset District: This area, the southwestern quadrant of the city, is bounded by Lincoln Way (Golden Gate Park) on the north; 7th Avenue, Laguna Honda, Woodside Avenue, O'Shaughnessy Boulevard and other smaller streets (Juanita, Casita, El Verano, Ashton, Orizaba) on the eastern boundary; and by the San Mateo County line on the southern boundary. Super District #4 includes the following neighborhoods and districts: Inner Sunset, the Sunset District, Sunset Heights, Parkside, Lake Merced District, Park-Merced, Ingleside Heights, West Portal and St. Francis Wood.Super District #5 - Daly City/San Bruno: This northern San Mateo County Super District includes the communities of Daly City, Colma, Brisbane, South San Francisco, Pacifica, San Bruno, Millbrae, and the north part of Burlingame. The boundary between Super District #5 and Super District #6 is Broadway, Carmelita Avenue, El Camino Real, Easton Drive, the Hillsborough / Burlingame city limits, Interstate 280, Skyline Boulevard, the Pacifica city limits, and the Montara Mountain ridgeline extending to Devil's Slide on the coast.Super District #6 - San Mateo/Burlingame: The central San Mateo County Super District includes the communities of Hillsborough, San Mateo, Foster City, Belmont, the southern part of Burlingame, and the coastside communities of Montara, Moss Beach, El Granada, and Half Moon Bay. The southern boundary of Super District #6 is the Foster City city limits, the Belmont/San Carlos city limits, Interstate 280, Kings Mountain, Lobitos Creek extending to Martins Beach on the coast.Super District #7 - Redwood City/Menlo Park: The southern San Mateo County Super District includes the communities of San Carlos, Redwood Shores, Redwood City, Atherton, Menlo Park, East Palo Alto, Woodside, Portola Valley, and the coastside communities of San Gregorio and Pescadero.Super District #8 - Palo Alto/Los Altos: This Santa Clara County Super District includes the communities of Palo Alto, Los Altos, Los Altos Hills, and the western part of Mountain View. Boundaries include the San Mateo County line, US-101 on the north, and Cal-85 (Stevens Creek Freeway) and Stevens Creek on the east.Super District #9 - Sunnyvale/Mountain View: This is the "Silicon Valley" Super District and includes the communities of Mountain View (eastern part and shoreline), Sunnyvale, Santa Clara (northern part), Alviso, and San Jose (northern part). Also included in this Super District is the "Golden Triangle" district. Super District #9 is bounded by US-101, Cal-85, Stevens Creek on the western boundary; Homestead Road on the southern boundary; Pierce Street, Civic Center Drive and the SP tracks in Santa Clara City; and Interstate 880 as the eastern boundary.Super District #10 - Cupertino/Saratoga: This Super District is located in south central Santa Clara County and includes the communities of Cupertino, Saratoga, Santa Clara City (southern part), Campbell (western part), San Jose (western part), Monte Sereno, Los Gatos and Redwood Estates. This area is bounded by Stevens Creek and the Santa Cruz Mountains on the west, Homestead Road on the north, Interstate 880/California Route 17 on the east; Union Avenue, Camden Avenue and Hicks Road (San Jose) also on the eastern boundary; and the Santa Clara/Santa Cruz county line on the south.Super District #11 - Central San Jose: This central Santa Clara County Super District is comprised of San Jose (central area), Santa Clara City (downtown area), and Campbell (east of Cal-17). The general boundaries of Super District #11 are Interstate 880/California Route 17 on the west; US-101 on the east; and the Capitol Expressway, Hillsdale Avenue, Camden Avenue, and Union Avenue on the south boundary.Super District #12 - Milpitas/East San Jose: This eastern Santa Clara County Super District includes the City of Milpitas, and the East San Jose communities of Berryessa, Alum Rock, and Evergreen. Boundaries include Interstate 880 and US-101 freeways on the west; San Jose City limits (Evergreen) on the south; and the mountains on the east.Super District #13 - South San Jose: This south-central Santa Clara County Super District includes the southern part of San Jose including the Almaden and Santa Teresa neighborhoods. Super District #13 is surrounded by Super District #10 on the west; Super District #11 on the north; Super District #12 on the northeast; and Super District #14 on the south at Metcalf Road (Coyote).Super District #14 - Gilroy/Morgan Hill: This area of Santa Clara County is also known as "South County" and includes the communities of Gilroy, Morgan Hill, San Martin and the Coyote Valley. Also included in this Super District are Loma Prieta (western boundary of the Super District) and Mount Hamilton in the northeastern, rural portion of Santa Clara County. This area is bounded by Santa Cruz and San Benito Counties on the south, and Merced and Stanislaus Counties on the eastern border.Super District #15 - Livermore/Pleasanton: This is the eastern Alameda County Super District including the Livermore and Amador Valley communities of Livermore, Pleasanton, Dublin, San Ramon Village, and Sunol. This Super District includes all of eastern Alameda County east of Pleasanton Ridge and Dublin Canyon.Super District #16 - Fremont/Union City: The southern Alameda County Super District includes the communities of Fremont, Newark and Union City. The boundaries for this Super District are the Hayward/Union City city limits on the north side; the hills to the immediate east; the Santa Clara/Alameda County line on the south; and the San Francisco Bay on the west.Super District #17 - Hayward/San Leandro: This southern Alameda County Super District includes the communities of Hayward, San Lorenzo, San Leandro, Castro Valley, Cherryland, and Ashland. The northern border is the San Leandro/Oakland city limits.Super District #18 - Oakland/Alameda: This northern Alameda County Super District includes the island city of Alameda, Oakland, and Piedmont. The Oakland neighborhoods of North Oakland and Rockridge are in the adjacent Super District #19. The border between Super Districts #18 and #19 are the Oakland/Emeryville city limits; 52nd and 51st Streets; Broadway; and Old Tunnel Road.Super District #19 - Berkeley/Albany: This northern Alameda County Super District includes all of Emeryville, Berkeley, and Albany, and the Oakland neighborhoods in North Oakland and Rockridge. The Super District is surrounded by the Alameda/Contra Costa County lines; the San Francisco Bay; and the Oakland Super District.Super District #20 - Richmond/El Cerrito: This is the western Contra Costa Super District. It includes the communities of Richmond, El Cerrito, Kensington, Richmond Heights, San Pablo, El Sobrante, Pinole, Hercules, Rodeo, Crockett, and Port Costa. The eastern boundary to Super District #20 is defined as the Carquinez Scenic Drive (east of Port Costa); McEwen Road; California Route 4; Alhambra Valley Road; Briones Road through the Regional Park; Bear Creek Road; and Wildcat Canyon Road to the Alameda/Contra Costa County line.Super District #21 - Concord/Martinez: This is one of three central Contra Costa County Super Districts. Super District #21 includes the communities of Concord, Martinez, Pleasant Hill, Clayton, and Pacheco. This area is bounded by Suisun Bay on the north; Willow Pass and Marsh Creek on the east; Mt Diablo on the southeast; and Cowell Road, Treat Boulevard, Oak Grove Road, Minert Road, Bancroft Road, Oak Park Boulevard, Putnam Boulevard, Geary Road, and Pleasant Hill Road on the south; and Briones Park, Alhambra Valley Road and Cal-4 on the west.Super District #22 - Walnut Creek: This central Contra Costa County Super District includes the communities of Walnut Creek, Lafayette, Moraga and Orinda. The latter three communities are more popularly known as Lamorinda. The border with Super District #23 generally follows the southern city limits of Walnut Creek.Super

The TIGER/Line shapefiles and related database files (.dbf) 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 shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. The All Roads Shapefile includes all features within the MTDB Super Class "Road/Path Features" distinguished where the MAF/TIGER Feature Classification Code (MTFCC) for the feature in MTDB that begins with "S". This includes all primary, secondary, local neighborhood, and rural roads, city streets, vehicular trails (4wd), ramps, service drives, alleys, parking lot roads, private roads for service vehicles (logging, oil fields, ranches, etc.), bike paths or trails, bridle/horse paths, walkways/pedestrian trails, and stairways.

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.

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 BackgroundThe 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.Since 1950 DWR has conducted over 250 land use surveys of all or parts of California's 58 counties. Early land use surveys were recorded on paper maps of USGS 7.5' quadrangles. In 1986, DWR began to develop georeferenced digital maps of land use survey data, which are available for download. Long term goals for this program is to survey land use more frequently and efficiently using satellite imagery, high elevation digital imagery, local sources of data, and remote sensing in conjunction with field surveys.There are currently 58 counties and 278 DAUs in California.Due to some DAUs being split by county lines, the total number of DAU’s identifiable via DAU by County is 782.**ADDENDUM**The Development of Boundaries for Hydrologic Studies for the Sacramento Valley Region[Detailed Analysis Units made up of a grouping of the Depletion Study Drainage Areas (DSA) boundaries occurred on the Eastern Foothills and Mountains within the Sacramento Region. Other DSA’s were divided into two or more DAU’s; for example, DSA 58 (Redding Basin) was divided into 3 DAU’s; 143,141, and 145. Mountain areas on both the east and west side of the Sacramento River below Shasta Dam went from ridge top to ridge top, or topographic highs. If available, boundaries were set adjacent to stream gages located at the low point of rivers and major creek drainages.Later, as the DAU’s were developed, some of the smaller watershed DSA boundaries in the foothill and mountain areas were grouped. The Pit River DSA was split so water use in the larger valleys (Alturas area, Big Valley, Fall River Valley, Hat Creek) could be analyzed. A change in the boundary of the Sacramento Region mountain area occurred at this time when Goose Lake near the Oregon State Line was included as part of the Sacramento Region.The Sacramento Valley Floor hydrologic boundary was at the edge of the alluvial soils and slightly modified to follow the water bearing sediments to a depth of 200 feet or more. Stream gages were located on incoming streams and used as an exception to the alluvial soil boundary. Another exception to the alluvial boundary was the inclusion of the foothills between Red Bluff and the Redding Basin. Modifications of the valley floor exterior boundary were made to facilitate analysis; some areas at the northern end of the valley followed section lines or other established boundaries.Valley floor boundaries, as originally shown in Bulletin 2, Water Utilization and Requirements of California, 1955 were based on physical topographic features such as ridges even if they only rise a few feet between basins and/or drainage areas. A few boundaries were based on drainage canals. The Joint DWR-USBR Depletion Study Drainage Areas (DSA) used drainage areas where topographic highs drained into one drainage basin. Some areas were difficult to study, particularly in areas transected by major rivers. Depletion Study Drainage Areas containing large rivers were separated into two DAU’s; one on each side of the river. This made it easier to analyze water source, water supply, and water use and drainage outflow from the DAU.Many of the DAUs that consist of natural drainage basins have stream gages located at outfall gates, which provided an accurate estimate of water leaving the unit. Detailed Analysis Units based on political boundaries or other criteria are much more difficult to analyze than those units that follow natural drainage basins.]**END ADDENDUM**.............................................................................................................................................cnty18_1 metadata Summary:(*See metadata for CAL-FIRE cnty18_1). CAL-FIRE cnty18_1 boundary feature class is used for cartographic purposes, for generating statistical data, and for clipping data. Ideally, state and federal agencies should be using the same framework data for common themes such as county boundaries. This layer provides an initial offering as "best available" at 1:24,000 scale.cnty18_1 metadata Description:(*See metadata for CAL-FIRE cnty18_1).cnty18_1 metadata Credits:CAL-FIRE cnty18_1 metadata comment:This specific dataset represents the full detailed county dataset with all coding (islands, inlets, constructed features, etc.). The user has the freedom to use this coding to create definition queries, symbolize, or dissolve to create a more generalized dataset as needed.In November 2015, the dataset was adjusted to include a change in the Yuba-Placer county boundary from 2010 that was not yet included in the 14_1 version of the dataset (ord. No. 5546-B). This change constitutes the difference between the 15_1 and 14_1 versions of this dataset.In March 2018, the dataset was adjusted to include a legal boundary change between Santa Clara and Santa Cruz Counties (December 11, 1998) as stated in Resolution No. 98-11 (Santa Clara) and Resolution No. 432-98 (Santa Cruz). This change constitutes the difference between the 18_1 and 15_1 versions of this dataset.(*See metadata for CAL-FIRE cnty18_1). - U.S. Bureau of Reclamation, California Department of Conservation, California Department of Fish and Game, California Department of Forestry and Fire protection