Watersheds within Fairfax County. There are 30 watersheds delineated across Fairfax County.

Existing land use categories for current land uses in Fairfax County as of the VALID_TO date in the attribute table. For methodology and a data dictionary please visit: https://www.fairfaxcounty.gov/demogrph/opendata/ipls-methodology-data-dictionary.pdf

Quarries in Fairfax County.

This data release documents spatiotemporal water-quality, landscape, and climatic conditions in Fairfax County, Virginia from 2007 through 2018. These data were used to evaluate the water-quality and ecological condition of 20 Fairfax County watersheds monitored since 2007. Data include measures of water-quality, precipitation, air temperature, land use, land cover, wastewater and stormwater infrastructure, soil properties, geologic setting, and stream networks. Annual values from 2007 through 2018 are reported for data expected to change over time. Watershed-specific values are reported for data that differ across the landscape. Annual values for the 20 study watersheds and Fairfax County are reported in the file "Spatiotemporal Predictors.csv". A description of each spatiotemporal variable, including data sources, are provided in the file "Data Dictionary.csv".

Park land maintained by Fairfax County Park Authority.

Landfill properties in Fairfax County.

The four planning areas in Fairfax County. Each area is a part of the overall County comprehensive plan.

Datasets used to quantify and value the ecosystem service of sediment and nutrient retention for floodplains within the Difficult Run watershed located in Fairfax County, Virginia. Geospatial datasets include a digital elevation model (DEM), a hydrologically conditioned DEM, output from the USGS Stream Channel and Floodplain Metric Toolbox, and field data sets used to develop regression models to predict sediment and nutrient retention services for stream within the Difficult Run watershed.

List and description of datasets available on Open Data for Fairfax County, Virginia

Stormwater, wastewater, and drinking water data from a variety of sources is being compiled. Stormwater data has (is) been collected for many urbanized town and village centers statewide. Wastewater data is available for some towns and is currently being developed more fully as data becomes available. Drinking water data is rarely available. Point, line, and polygon data was collected and compiled through field observations, municipal member knowledge, ortho-photo interpretation, digitization of georeferenced town plans and record drawings, and state stormwater permit plans. Accuracy of all data is for planning purposes and field verification is at the users discretion. Subwatershed Drainage systems were mapped to establish the connectivity of the stormwater features, and to show where runoff from impervious surfaces in various subwatersheds within an urbanized area eventually enters the receiving water. Subwatershed boundaries were drawn by hand using a variety of elevation data and corelated to each towns Stormwater Infrastructure report.