WebLogis, Loudoun County's Online Mapping System. Provides access to the County’s Enterprise Geographic Information System data layers.

More MetadataData updated daily.A parcel is a tract or plot of land surveyed and defined by legal ownership. Data were compiled from plats and deeds recorded at the Clerk of the Court and from historic tax maps. Source material was digitized or the coordinates were entered into the database via ARC/INFO Coordinate Geometry (COGO). Digital data from engineering companies has also been incorporated for newer subdivisions. A MCPI number is used to identify each parcel, which is a unique ID number further explained below. Purpose: Parcels are used to support a variety of services including assessment, permitting, subdivision review, planning, zoning, and economic development. Parcel data were initially developed to replace existing tax maps. As a result, there are parcel polygons digitized from tax maps that do not represent land parcels but are taxable entities such as leaseholds or easements. Supplemental Information: Data are stored in the corporate ArcSDE Geodatabase as a feature class. The coordinate system is Virginia State Plane (North), Zone 4501, datum NAD83 HARN. Maintenance and Update Frequency: Parcels are updated on an hourly basis from recorded deeds and plats. Depending on volume and date of receipt of recordation information, data may be updated 2-3 weeks following recordation. Completeness Report: Features may have been eliminated or generalized due to scale and intended use. To assist Loudoun County, Virginia in the maintenance of the data, please provide any information concerning discovered errors, omissions, or other discrepancies found in the data. MCPI: 9 digit unique parcel ID that is a combination of: MAP, CELL, and PARCEL. MAP: 3 digit map number (001-701) corresponding with map tile index. CELL: 2 digit map grid location of parcel center; the grid is comprised of 1000 by 1000 ft grid cells numbered as rows and columns (Columns numbered > 5 6 7 8 9 0; Rows numbered > 1 2 3 4). PARCEL: 4 digit location of polygon center based on the 1927 Virginia State Plane coordinate grid where an easting and northing measurement is taken. example: 6654 from: E 2229668 N475545. The MAP, CELL, and PARCEL values of a parcel do not change when a parcel is altered by a boundary line adjustment or becomes residue from a subdivision. The MAP, CELL, and PARCEL values may therefore be inconsistent with the location of polygon center. MAP, CELL, and PARCEL values have been manually altered for some parcels to agree with other databases; as a result, not all parcels can be located by the MAP, CELL, and PARCEL values. Data Owner: Office of Mapping and Geographic Information

Loudoun County, Virginia Boundary

In September 2020, the Loudoun County Board of Supervisors directed staff to document telecommunication projects completed, in-progress, and future projects, using the 2014 Wireless GAP Analysis and the Segra Dark Fiber Area Network. Staff mapped the data identified by the Board, as well as other information related to telecommunication projects. This information was then used to identify select unserved or underserved geographic areas of the county.The companion interactive map allows the user to turn on or off all layers used in the project.

This map provides the location of the original land grants within present day Loudoun County from the early 1700s to early 1800s. To view a list of sortable attributes of the information, please click on the Table button in the upper right corner of the map. For additional details, please visit here.

These are the original grantings of land within the Northern Neck Proprietary by Thomas, the 6th Lord of Fairfax and/or his agents until the mid 1780s during the settlement of Virginia. The map shows the approximate location of the original land grant as well as information on the grantee, the acreage of the grant (as calculated using the GIS), the year, and additional comments. The map is intended for historical reference only, as insufficient and incomplete original boundary surveys have resulted in potential inaccurate boundaries.

The original research for all of the land grants mapped in this application was completed by historian Wynne Saffer. They were originally mapped on USGS Quadrangles at a scale of 1:24000, then scanned to a digital file and the boundaries digitized by the Loudoun County Office of Mapping and Geographic Information staff.

The orginial land grant research is located at Thomas Balch Library. The land grants can be viewed on microfilm using the Record Number as a reference. This map is also located on the Office of Mapping and Geographic Information online map gallery, which can be found here.

For more information about Loudoun County's GIS, please contact Office of Mapping and Geographic Information.

Twentieth Century history highlighting Black families from the Nokes area (present-day Dulles Town Center) of the Eastern Loudoun County, Virginia. Information and locations are derived from an interview with Ms. Carrie Nokes in 2002 as well as historic maps, imagery, and documents. Carrie Nokes sat down for an interview with Pauline Singletary (Chair of the Black History Committee of Friends of the Thomas Balch Library, Inc) to discuss the community around Nokes. The interview was conducted on March 14, 2002. The following story map highlights portions of her recollections of early 20th century life in eastern Loudoun County.

Loudoun County annually obtains leaf-off, aerial imagery in the spring. Since 2004, the County has utilized this imagery to support the development of an annual digital orthophoto base."Loudoun County - Latest" (LATEST_ORTHO) is the most recent year available.

Loudoun County annually obtains leaf-off, aerial imagery in the spring. Since 2004, the County has utilized this imagery to support the development of an annual digital orthophoto base. In 2023, the imagery was captured with a Vexcel Ultracam Eagle digital camera, in 4-band (R,G,B, and NIR) format. These files contain 1-foot ground-resolution, 8-bit, 4-band orthorectified aerial image map products in GeoTIFF version 6.0 file format. GeoTIFF files are uncompressed raster images complete with TFW coordinate information. The aerial imagery project encompasses the entire land area of the County of Loudoun, VA. Images were flown during leaf-off conditions and cover 5000' by 5000' and are tiled according to the VBMP 200-scale gridding schema (Virginia Geographic Information Network)."March 2023 Photography flown by The Sanborn Map Company, Inc. Colorado Springs, CO." "Digital Orthophotography compiled by Sanborn Map Company, Inc. Colorado Springs, CO"

More MetadataPlanar Index of Loudoun County is used primarily for locator reference and establishes the first 3 digits in the MCPI number for parcels. This information can also be known as Map, Sheet, or Tile number in other data sets.The index coverage contains approximately 690 polygons which coincide with Loudoun County's GIS library tile system. Digital Data orders and associated maps are available to the extent of any individual tile as well as county wide. Each tile is designated with a unique ID number that is used in GIS data orders to identify the area of interest.

The Crops Suitability Tool combines soil types, aspect (slope orientation), and percentage of slope to determine the best and least suitable sites in which to grow crops in Loudoun County. It includes different types of Agricultural Soils (Prime Farmland, Secondary Cropland, Grassland Agriculture, Orchard Land, Woodland Use and Wildlife) and its grade of suitability for grapes, tree fruits, hops, vegetables, flowers, herbs, small fruits, field crops, pasture and hay.A spatial model uses existing geographic data to predict an outcome. In this application, we combined soil types, aspect (slope orientation), and percentage of slope to determine the best and least suitable site in which to grow crops in Loudoun County, Virginia. It includes different types of Agricultural Soils (Prime Farmland, Secondary Cropland, Grassland Agriculture, Orchard Land, Woodland Use and Wildlife) and its grade of suitability for grapes, tree fruits, hops, vegetables (ethnic crops), flowers, herbs, and small fruits, field crops, pasture, and hay.This tool does not account for the incidence and prevalence of any type of pests (weed, insects, and diseases -nematodes, fungi, bacteria, or viruses) or weather conditions that can affect crops. The accuracy of the predicted outcomes is not 100% (for example: 17B soils in a concave position are not suitable for growing perennial crops or high cash valued crops); therefore, it is highly recommended to contact VCE Loudoun Commercial Horticulturist Beth Sastre to get a soil map report of the property and/or to have a site evaluation for further recommendation.We encourage farmers, beginner farmers, people interested in farming, and realtors to use this tool to make guided decisions before starting a crop for the first time or buying land. If you see major discrepancies while using this tool, please report them.

The abundance of natural, environmental and heritage resources define Loudoun County’s unique sense of place. These natural, environmental and heritage resources include: The Potomac River, other major rivers and smaller stream corridors Floodplains Wetlands Steep slopes Ridges and mountainsides Forested and vegetative landscapes Limestone geology areas Farmlands Soil resources Important plant and wildlife habitats Historic and archaeological sites Scenic areas and corridors Designated heritage areas Battlefields Historic cemeteries Cultural landscapes The Loudoun County 2019 Comprehensive Plan contains policies that provide guidance for the preservation, protection and incorporation of natural, environmental and heritage resources as part of the site design and development process. The Loudoun County Zoning Ordinance contains regulations and development standards that implement the county’s policies. The preservation, protection and enhancement of the county’s natural, environmental and heritage resources contribute directly and indirectly to Loudoun’s economy and the quality of life of its residents and visitors.

More MetadataWater Bodies are used for water supply planning, the administration of related zoning restrictions, and to locate water supplies in rural areas for fighting fires.Supplemental_Information:Data are stored in the corporate ArcSDE Geodatabase as a polygon feature class. The coordinate system is Virginia State Plane (North), Zone 4501, datum NAD83 HARN, Vertical datum, NAVD88, US Survey foot units. OMAGI updates all base map data via a photogrammetric process, using aerial imagery that is flown yearly in phases. A different portion of the County is updated each year with the base map maintenance services contract, depending upon development patterns and update funding. See "Lineage" section for the list of extents for each Phase area, which are listed as “Data Sources”. The field “UPD_DATE” indicates the date a feature was last re-mapped, although it may have been reviewed for changes more recently. For a map of the most recent reviews and updates within the county, please see http://www.flickr.com/photos/omagi/8371423446/

More MetadataLoudoun County was founded in 1757. Loudoun's boundary with Maryland is the mean low water mark of the Potomac River on the Virginia side; it has not been surveyed. Loudoun's boundary with Prince William County is the Bull Run Creek. The border has not been modified for recent surveys. Individual plats along the Potomac and Bull Run Rivers have not resulted in a change in the border along those rivers- since measurements of the waters edge vary seasonally and the County Boundary needs to be seamless and constant. Many decades ago tax commissioners from surrounding jurisdictions assigned parcels to one jurisdiction or another rather than splitting parcels. Currently there is a mix of parcels split by a County Boundary, parcels taxed entirely in Loudoun, and portions of parcels within the County but taxed by another jurisdiction. The Office of the Commissioner of the Revenue dictates how these parcels are taxed, as do other jurisdictions. In 1957, the boundary with Fairfax County was re-established and finalized. The boundary with Fauquier County was surveyed and monumented in 1966. The boundary with Clarke County was surveyed in 1989, and the boundary survey with Jefferson County West Virginia was completed in 1998. The West Virginia, Fairfax, Fauquier, and Clarke boundary arcs were created by generating coverages from the monument coordinates using the generate command.

This application uses surface type data to illustrate the extensive network of unpaved roads in Loudoun County, Virginia.

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This GIS layer contains the geographical boundaries of the 2010 census tracts for Loudoun County, Virginia. The 2010 Census tract boundaries are used for Census Bureau statistical data tabulation purposes, including the 2010 Decennial Census and American Community Surveys.

Census tracts are part of the sub-county census geography hierarchy of tracts, block groups, and blocks. The three census geographies nest to each other, forming a hierarchy of census tract, followed by block groups, and then blocks, with blocks being the smallest. A census tract consists of one or more census block groups and is a cluster of census blocks within the same census tract. Tracts are uniquely identified within a County by a six digit number. The last two digits will be zeros unless earlier divisions of the census tract occurred as a result of population growth.

Loudoun County's tracts were delineated by Loudoun County Government during the Census Bureau's Participant Statistical Areas Program for the 2010 Census. The 2010 Census tract layer has been modified from the Census Bureau's Tiger line file. Users should be aware that the Census's Tiger line data is devised from a mix of national and local GIS data sets. When the Tiger line data is overlaid with Loudoun County Government's detailed GIS layers it can be determined that the Census Bureau's Tiger line boundaries in some cases are slightly off from the actual location of the physical features, natural features, and governmental units such as town boundaries that they are designated to follow. The 2010 Loudoun census tract layer was generated by Loudoun County so that the tract boundaries would overlay with the features in Loudoun County's GIS data sets that the boundary are designated to follow.

The geology of Loudoun County, Virginia, was mapped in 1988 through 1991 under a cooperative agreement between the U.S. Geological Survey (USGS) and the Loudoun County Department of Environmental Resources.This geologic map was compiled in 1993 from a series of detailed published and unpublished field investigations at scales of 1:12,000 and 1:24,000. Some of these same datawere compiled as a digital geologic map at 1:100,000 scale (Burton and others, 1992a) and were the basis for a cost-benefit analysis of the societal value of geologic maps (Bernknopf and others, 1993).The data was later revised and published by USGS in the Open File Report, MAP OF-99-150, GEOLOGIC MAP OF LOUDOUN COUNTY, VIRGINIA By Scott Southworth, W.C. Burton, J.S. Schindler, and A.J. Froelich1 with contributions on the geology of the Piedmont province by A.A. Drake, Jr., and R.E. Weems and an aeromagnetic survey by D.L. Daniels, W.F. Hanna, and R.E. Bracken.Data current as of April 2018

The stormwater structures data is comprised of points (inlets, manholes, pipe ends, culvert ends, and control devices). The pipe and culvert point structures, typically one at each end of the pipe/culvert line, include the stormwater infrastructure where there is a change in pipe direction. The data was collected primarily in eastern Loudoun in the more urbanized areas of the County. The data was collected in the field using GPS so that at least 95% of data is accurate to less than 3.28 ft. (1 m).

More MetadataThis feature class contains all the county owned and leased property data of Loudoun County, VA as of April 2024. It is comprised from internal data and information sources combined with parcel data.

The data set identifies the six county-administered Historic and Cultural Conservation District areas within Loudoun County. The County-designated districts include six Historic and Cultural Conservation Districts (Aldie, Bluemont, Goose Creek, Oatlands, Taylorstown, and Waterford) and one Historic Roadways District (Beaverdam Creek). The Historic Districts are Zoning Overlay Districts and are subject to Loudoun County Zoning Ordinance, Article VI, Section 6-1800, Designation of Historic Districts and Section 6-1900, Permits in Historic Districts. The Beaverdam Creek Historic Roadways District differs from the other districts, as the Roadways District only includes the part of the parcel located within a 35-foot buffer in each direction from the centerline of a designated roadway. The Planning Department administers the County's Historic Districts Program.

Proffered conditions may apply to certain properties. To determine whether proffered conditions apply or to determine the zoning of a specific property, please contact the Zoning Administrator. For more information, please visit the Loudoun County webpage on the Zoning Ordinance, or contact the Department of Planning and Zoning