Loudoun 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.

Loudoun County was founded and surveyed 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 Assessor's office dictates how these parcels are taxed, as do other jusidictions. 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.

Geographic boundary, portraying extent and limits of land recognized as Fairfax County, Commonwealth of Virginia. Defined in part by both physical features (Potomac and Occoquan Rivers), and monumented legal boundaries for surrounding jurisdictions (State of Maryland, Arlington, Loudoun, and Prince William Counties, cities of Alexandria and Falls Church). This includes the closest neighbors to Fairfax County jurisdictional boundaries.

This layer contains data defining the exterior boundaries of subdivided land within Fairfax County, Virginia. The Subdivision layer was created to depict subdivided land areas defined by recorded documents (plats) for the County of Fairfax. The polygons portrayed on this layer define the second portion of the County's Parcel Identification Numbering system (Map / Subdivision / Block / Parcel). Information portrayed on this layer was initially derived from the ink-on-mylar property maps maintained by the County since the early 1960s.For more information go to the Geospatial Property Data Guide.Contact: Fairfax County Department of Information Technology GIS DivisionData Accessibility: Publicly AvailableUpdate Frequency: DailyLast Revision Date: 1/1/2000Creation Date: 1/1/2000Feature Dataset Name: GISMGR.PARCELSLayer Name: GISMGR.SUBDIVISIONS

This layer contains data defining the exterior boundaries of subdivided land within subdivisions in Fairfax County, Virginia. The Block layer was created to depict subdivided land areas within subdivisions defined by recorded documents (plats) for the County of Fairfax. The polygons portrayed on this layer define the third portion of the County's Parcel Identification Numbering system (Map / Subdivision / Block / Parcel). Blocks are indicated on the property maps using a number within a single circle and boundaries that have heavy dashed lines. Information portrayed on this layer was initially derived from the ink-on-mylar property maps maintained by the County since the early 1960s.For more information go to the Geospatial Property Data Guide.Contact: Fairfax County Department of Information Technology GIS DivisionData Accessibility: Publicly AvailableUpdate Frequency: DailyLast Revision Date: 1/1/2000Creation Date: 1/1/2000Feature Dataset Name: GISMGR.PARCELSLayer Name: GISMGR.BLOCKS

This layer contains data defining the exterior boundaries of land under common ownership, typically within condominium properties within Fairfax County, Virginia. The common area layer was created to depict these areas of land that do not actually have parcel identification numbers. These areas of land are owned by a group of properties that lie within the common area. Information portrayed on this layer was initially derived from the ink-on-mylar property maps maintained by the County since the early 1960s. Contact: Fairfax County Department of Information Technology GIS DivisionData Accessibility: Publicly AvailableUpdate Frequency: DailyLast Revision Date: 1/1/2000Creation Date: 1/1/2000Feature Dataset Name: GISMGR.PARCELSLayer Name: GISMGR.COMMON_AREAS

This layer contains the boundaries of special tax areas as defined by the taxing authority of Fairfax County. These are special tax districts where additional fees are levied on the properties within the districts. For current tax rates on properties for each of the tax areas refer to this page: https://www.fairfaxcounty.gov/taxes/real-estate/tax-rates Contact: Fairfax County Department of Information Technology GIS DivisionData Accessibility: Publicly AvailableUpdate Frequency: DailyLast Revision Date: 1/1/2000Creation Date: 1/1/2000Feature Dataset Name: GISMGR.PARCELSLayer Name: GISMGR.SPECIAL_TAX_AREAS

Loudoun County, Virginia Boundary

More MetadataAt the July 3, 2012 Loudoun Board of Supervisor's Business Meeting, the Board agreed to be a funding partner with the Metropolitan Washington Airports Authority (MWAA) and Fairfax County for the Phase II extension of Metrorail to Dulles Airport and Ashburn. Loudoun County’s rail service districts were established on December 5, 2012 to fund the construction and maintenance of the stations, rail line, and rail related facilities and services. All parcels in the districts, residential and commercial, have a special property tax rate for funding of the rail. Tax collection for the districts is for Tax Year 2013 and future years.The boundaries of the Metrorail Service District were defined using physical features such as major roads and streams within two miles of stations. In some cases, parcel boundaries were used to develop the tax district boundary. The Route 606/Airport and Route 772 station service districts were defined using half-mile radii around the four proposed rail stations in or near Loudoun County: 1) Route 772, 2) Route 606, 3) Dulles Airport, and 4) Route 28. These radii were used as approximate guidelines. At the time the districts were established, the districts encompassed primarily commercial land. Only a few existing residential units were included within these districts at the time the districts were established.The features the boundaries follow may have been generalized due to scale and intended use.

Boundaries of attendance areas for middle school Advanced Academic Program (AAP). It depicts all of the AAP middle school attendance areas for Fairfax County Public Schools.Contact: Fairfax County Public School (FCPS) GISData Accessibility: Publicly availableUpdate frequency: AnnuallyLast Revision Date: 9/11/2024Creation Date: 05/13/2019Feature Dataset Name: SCHMGR.SCHOOLSLayer source name: SCHMGR.MS_AAP_ATTENDANCE_AREAS

Stormwater easements (ex: storm drainage, storm sewer, floodplain) as captured from recorded plats using coordinate geometry (COGO) capture method. All easements are contained within the Fairfax County boundary. This dataset does not comprise all stormwater drainage easements in Fairfax County and additional research may be necessary to identity easements not yet captured.

The Chesapeake Bay Preservation Ordinance was adopted to protect our local streams and one of the world's most productive estuaries, the Chesapeake Bay, from pollution due to land use and development. All of Fairfax County drains into the Potomac River and ultimately the Chesapeake Bay. In an effort to protect and improve the quality of these waterways, sensitive areas along streams throughout Fairfax County have been designated as Resource Protection Areas.State regulations require that Resource Protection Areas (RPAs) be designated around all water bodies with perennial flow. Perennial flow means that water always flows in the stream or other water body except during periods of drought. The Department of Public Works and Environmental Services conducted field studies to identify all perennial streams throughout the county and used this information to prepare a set of maps showing the location of RPAs as defined under the revised Ordinance. The maps were adopted by the Board on November 17, 2003. The data include the boundaries of the RPAs adopted by the Board in 1993 and the additional RPAs adopted by the Board in 2003. These are general locations of RPA boundaries for planning purposes and the actual limits may be further refined by detailed field studies conducted at the time a plan is submitted to obtain a permit to develop a property.Any areas within Fairfax County not contained within the RPAs are Resource Management Areas (RMAs). Together, the RPAs and RMAs comprise the Chesapeake Bay Preservation Areas.

Layer of Fairfax County Police Station boundaries. Data is stored in the County's Enterprirse Geodatabase.