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.

Boundaries for Fairfax County High School Attendance

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.

Fairfax County Supervisor (Magisterial) Districts.

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.

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.

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.

2015 boundaries portraying elementary school attendance areas as defined by Fayette County Public Schools. Under the current regulation of elementary school districts, it is possible to live in a particular school's primary attendance area and be unable to attend that school due to fullness. Therefore, it is recommended to check with the Fayette County Public Schools when using this information for specific decisions. (Polygon)

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.

Links to recordings of the Integrated Services Program and 9-1-1 & Geospatial Services Bureau webinar series, including NG9-1-1 GIS topics such as: data preparation; data provisioning and maintenance; boundary best practices; and extract, transform, and load (ETL). Offerings include:Topic: Virginia Next Generation 9-1-1 Dashboard and Resources Update Description: Virginia recently updated the NG9-1-1 Dashboard with some new tabs and information sources and continues to develop new resources to assist the GIS data work. This webinar provides an overview of changes, a demonstration of new functionality, and a guide to finding and using new resources that will benefit Virginia public safety and GIS personnel with roles in their NG9-1-1 projects. Wednesday 16 June 2021. Recording available at: https://vimeo.com/566133775Topic: Emergency Service Boundary GIS Data Layers and Functions in your NG9-1-1 PSAP Description: Law, Fire, and Emergency Medical Service (EMS) Emergency Service Boundary (ESB) polygons are required elements of the NENA NG9-1-1 GIS data model stack that indicate which agency is responsible for primary response. While this requirement must be met in your Virginia NG9-1-1 deployment with AT&T and Intrado, there are quite a few ways you could choose to implement these polygons. PSAPs and their GIS support must work together to understand how this information will come into a NG9-1-1 i3 PSAP and how it will replace traditional ESN information in order to make good choices while implementing these layers. This webinar discusses:the function of ESNs in your legacy 9-1-1 environment, the role of ESBs in NG9-1-1, and how ESB information appears in your NG9-1-1 PSAP. Wednesday, 22 July 2020. Recording available at: https://vimeo.com/441073056#t=360sTopic: "The GIS Folks Handle That": What PSAP Professionals Need to Know about the GIS Project Phase of Next Generation 9-1-1 DeploymentDescription: Next Generation 9-1-1 (NG9-1-1) brings together the worlds of emergency communication and spatial data and mapping. While it may be tempting for PSAPs to outsource cares and concerns about road centerlines and GIS data provisioning to 'the GIS folks', GIS staff are crucial to the future of emergency call routing and location validation. Data required by NG9-1-1 usually builds on data that GIS staff already know and use for other purposes, so the transition requires them to learn more about PSAP operations and uses of core data. The goal of this webinar is to help the PSAP and GIS worlds come together by explaining the role of the GIS Project in the Virginia NG9-1-1 Deployment Steps, exploring how GIS professionals view NG9-1-1 deployment as a project, and fostering a mutual understanding of how GIS will drive NG9-1-1. 29 January 2020. Recording available at: https://vimeo.com/showcase/9791882/video/761225474Topic: Getting Your GIS Data from Here to There: Processes and Best Practices for Extract, Transform and Load (ETL) Description: During the fall of 2019, VITA-ISP staff delivered workshops on "Tools and Techniques for Managing the Growing Role of GIS in Enterprise Software." This session presents information from the workshops related to the process of extracting, transforming, and loading data (ETL), best practices for ETL, and methods for data schema comparison and field mapping as a webinar. These techniques and skills assist GIS staff with their growing role in Next Generation 9-1-1 but also apply to many other projects involving the integration and maintenance of GIS data. 19 February 2020. Recording available at: https://vimeo.com/showcase/9791882/video/761225007Topic: NG9-1-1 GIS Data Provisioning and MaintenanceDescription: VITA ISP pleased to announce an upcoming webinar about the NG9-1-1 GIS Data Provisioning and Maintenance document provided by Judy Doldorf, GISP with the Fairfax County Department of Information Technology and RAC member. This document was developed by members of the NG9-1-1 GIS workgroup within the VITA Regional Advisory Council (RAC) and is intended to provide guidance to local GIS and PSAP authorities on the GIS datasets and associated GIS to MSAG/ALI validation and synchronization required for NG9-1-1 services. The document also provides guidance on geospatial call routing readiness and the short- and long-term GIS data maintenance workflow procedures. In addition, some perspective and insight from the Fairfax County experience in GIS data preparation for the AT&T and West solution will be discussed in this webinar. 31 July 2019. Recording available at: https://vimeo.com/showcase/9791882/video/761224774Topic: NG9-1-1 Deployment DashboardDescription: I invite you to join us for a webinar that will provide an overview of our NG9-1-1 Deployment Dashboard and information about other online ISP resources. The ISP website has been long criticized for being difficult to use and find information. The addition of the Dashboard and other changes to the website are our attempt to address some of these concerns and provide an easier way to find information especially as we undertake NG9-1-1 deployment. The Dashboard includes a status map of all Virginia PSAPs as it relates to the deployment of NG9-1-1, including the total amount of funding requested by the localities and awards approved by the 9-1-1 Services Board. During this webinar, Lyle Hornbaker, Regional Coordinator for Region 5, will navigate through the dashboard and provide tips on how to more effectively utilize the ISP website. 12 June 2019. Recording not currently available. Please see the Virginia Next Generation 9-1-1 Dashboard and Resources Update webinar recording from 16 June 2021. Topic: PSAP Boundary Development Tools and Process RecommendationDescription: This webinar will be presented by Geospatial Program Manager Matt Gerike and VGIN Coordinator Joe Sewash. With the release of the PSAP boundary development tools and PSAP boundary segment compilation guidelines on the VGIN Clearinghouse in March, this webinar demonstrates the development tools, explains the process model, and discusses methods, tools, and resources available for you as you work to complete PSAP boundary segments with your neighbors. 15 May 2019. Recording available at: https://www.youtube.com/watch?v=kI-1DkUQF9Q&feature=youtu.beTopic: NG9-1-1 Data Preparation - Utilizing VITA's GIS Data Report Card ToolDescription: This webinar, presented by VGIN Coordinator Joe Sewash, Geospatial Program Manager Matt Gerike, and Geospatial Analyst Kenny Brevard will provide an overview of the first version of the tools that were released on March 25, 2019. These tools will allow localities to validate their GIS data against the report card rules, the MSAG and ALI checks used in previous report cards, and the analysis listed in the NG9-1-1 migration proposal document. We will also discuss the purpose of the tools, input requirements, initial configuration, how to run them, and how to make sense of your results. 10 April 2019. Recording available at: https://vimeo.com/showcase/9791882/video/761224495Topic: NG9-1-1 PSAP Boundary Best Practice WebinarDescription: During the months of November and December, VITA ISP staff hosted regional training sessions about best practices for PSAP boundaries as they relate to NG9-1-1. These sessions were well attended and very interactive, therefore we feel the need to do a recap and allow those that may have missed the training to attend a makeup session. 30 January 2019. Recording not currently available. Please see the PSAP Boundary Development Tools and Process Recommendation webinar recording from 15 May 2019.Topic: NG9-1-1 GIS Overview for ContractorsDescription: The Commonwealth of Virginia has started its migration to next generation 9-1-1 (NG9-1-1). This migration means that there will be a much greater reliance on geographic information (GIS) to locate and route 9-1-1 calls. VITA ISP has conducted an assessment of current local GIS data and provided each locality with a report. Some of the data from this report has also been included in the localities migration proposal, which identifies what data issues need to be resolved before the locality can migrate to NG9-1-1. Several localities in Virginia utilize a contractor to maintain their GIS data. This webinar is intended for those contractors to review the data in the report, what is included in the migration proposal and how they may be called on to assist the localities they serve. It will still ultimately be up to each locality to determine whether they engage a contractor for assistance, but it is important for the contractor community to understand what is happening and have an opportunity to ask questions about the intent and goals. This webinar will provide such an opportunity. 22 August 2018. Recording not currently available. Please contact us at NG911GIS@vdem.virginia.gov if you are interested in this content.

Areas where volunteer groups operate within Fairfax County. The volunteer groups (also known as Community Based Organizations) are non-profit organizations that provide basic needs assistance to specific areas of the county. The groups work together to define their boundaries, often utilizing ZIP code boundaries for their edges. Some of the service areas overlap.

The voting precincts within Fairfax County.

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

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 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