Tidal wetlands are lands contiguous to a tidal body of water and lying between mean low water and mean high water subject to flooding by normal tides and wind tides. Projects that are within the Waters of the United States, including tidal wetlands may be subject to approval by the U.S. Army Corps of Engineers. Projects that are below mean low water, within the tidal wetland, sand dunes or beaches, may require review by the Virginia Marine Resources Commission. Land disturbances and related construction activities within the tidal wetland often require a wetlands permit in accordance with the Wetlands Zoning Ordinance or the Coastal Primary Sand Dune Zoning Ordinance. To facilitate the review by federal, state and local agencies that have overlapping regulatory jurisdiction, a single “Joint Permit Application” may be prepared and submitted for review.

The following types of land disturbing activities and construction projects will require a Joint Permit Application:

• Any construction project on, over or adjacent to a body of water.
• Any project in which fill material is placed in or near wetlands such as riprap.
• Projects designed to protect property at the water's edge.

- Apply for a Joint Permit Application from the U.S. Army Corps of Engineers.

The floodplain, as defined by Fairfax County, is the land area in and adjacent to streams that have a drainage area greater than 70 acres, and would be inundated by a flood event with a one percent chance of occurrence in any given year (commonly called the 100-year flood). The Federal Emergency Management Agency (FEMA) has delineated Special Flood Hazard Areas (SFHAs). To view mapped floodplain boundaries and other related information use the interactive map.  Please note, however, that the County Floodplain Regulations are more stringent than the federal minimum requirements of the National Flood Insurance Program.

• The Floodplain Regulations are found in Section 5105 of the Zoning Ordinance. Any Permitted Use in the Floodplain that qualifies requires a request for written determination from Land Development Services (LDS).  If not a Permitted Use, Special Exception Uses require an application submission to the Department of Planning and Development with approval by the Board of Supervisors.
• Flood information, FAQs related to floodplains or information regarding applications for Special Exception approval process is available online or call 703-324-1290, TTY 711.

RPAs are sensitive land areas that include the tidal shore, tidal wetland, perennial streams, and non-tidal wetlands.  The RPA buffer also includes the major floodplains. To view the maps online, visit Chesapeake Bay Preservation Area Maps online.

• Any project within the RPA will require approval in accordance with the Chesapeake Bay Preservation Ordinance (CBPO),  Chapter 118 of the County Code. The CBPO is administered by Land Development Services (LDS). The type of submission will depend on the type of project. For example, a water dependent facility that qualifies as an Allowed Use in the RPA will require approval of a Water Quality Impact Assessment (WQIA). Certain minor additions to an existing house may qualify for a request for an exception. Other projects may qualify for an exemption/exception request under Article 5 of CBPO. Requests under Article 6 of the CBPO will require a public hearing before the exception can be approved.
• Removal of invasive or undesirable plant species within a RPA may require a WQIA, 118-3-3(d). Removal of such invasive or noxious plants may involve several techniques including, but are not limited to, the following:
  • Mechanical removal of bamboo, russian olive, multi-flora rose, invasive grasses, etc.;
  • A maintenance schedule;
  • Chemical treatment of invasives, where necessary, under the supervision of a Virginia Certified Pest Applicator where required;
  • Supplemental planting with native species may be required. See PFM Sections 12-0404 and 12-0516.
• More information about the CBPO.