Floodplains and Flood Insurance Rate Maps

What Is a Floodplain?

A floodplain is any area of land that is susceptible to being inundated by unusual and rapid accumulation of water from any source. The Floodplain Ordinance in Chapter 48 of the Arlington County Code regulates development in flood zones.

What Is a Flood Insurance Rate Map?

The Federal Emergency Management Agency (FEMA) publishes flood hazard maps, called Flood Insurance Rate Maps (FIRM), for all areas of the United States, including Arlington. The purpose of a FIRM is to show the areas in a community that are subject to flooding and the risk associated with these flood hazards. Knowing your flood risk is the first step to flood protection.

How do I find the effective floodplain map for my property?

As a property owner, you should be aware of the flood risk for your property. All properties have some level of vulnerability. Knowing your flood risk is the first step to flood protection.

Go to FEMA’s Map Service Center to view the current floodplain map for your property. Click on the map to zoom to your address, or search by your address.
- Click on the blue View Map button to view a PDF map for your area, or click on Interactive Map to see a map with aerial imagery. You can also save a copy of the map.
- Zoom in to your property on the map.
- See what Flood Zone your property is listed in. Read the flood risk information associated with that zone.
On the County’s mapping web site:
- Click on the blue box that says “I want to…” on the left side of the map to change the visible layers on the map.
- Choose “flood zones”.
- Click on the + sign to expand that section. Select effective flood zones. Click on the small image of a legend to the right of the check mark to turn on the legend.
You also view the Virginia Flood Risk Information System Map.
View PDFs Flood Insurance Rate Maps for Arlington (updated in 2023). FEMA’s Arlington Flood Insurance Study 2023(PDF, 5MB)
Even if your property is not in a FEMA flood hazard zone, you may still have some risk of flooding. Here are some additional resources to help you:
- Check the Virginia Department of Conservation and Recreation FATHOM map.
- There are non-governmental sites such as Flood Factor (which may require a subscription) that some real estate sales sites have started to reference.
- Types of flooding in Arlington

If you are having problems finding the flood zone information for your property, contact us, and we can help create a map for you. Contact Elizabeth Thurber at 703-987-6546.

How Can I Reduce my Risk of Flooding?

Flooding can be a very costly disaster. The risk for flooding is affected by many variables, many of which can change over time, due to erosion, land use, weather events and other factors. The risk for flooding can vary within the same neighborhood and even property to property. Even if your property is not in a FEMA floodplain you may still have some risk of flooding. More than 40% of flood claims are from areas outside FEMA floodplains.

Learn more about what you can do reduce your risk of flooding, such as purchasing flood insurance.

Development in the Floodplain

If you are planning a construction project on your property and it is in the floodplain, you may need a Resource Protection Area (RPA) or floodplain permit/review. A permit is required when a development proposal is partly or entirely with an established RPA.

The Water Quality Impact Assessment Data Sheet is required if the property is located within 100 feet of a stream (in the Resource Protection Area). Check the RPA map for more details.
A Floodplain Development Permit is required if the property is partly or entirely within the 100-year flood plain or County-required Flood Buffer Zone. Please contact the County stormwater team for more information.

Letters of Map Revision

The County-wide flood maps for Arlington are only updated periodically. FEMA issues interim revisions to the maps for specific properties based on submittals from private property owners, developers, and from the County. These revisions are addendums to the County-wide maps. The approved map revisions and map changes (Letters of Map Revision (LOMR) and Letters of Map Amendment (LOMA)) can be found online at: https://msc.fema.gov/portal/advanceSearch .

Lower Long Branch Flood Letter of Map Revision

Lower Long Branch Effective and Proposed 1% (100 year) Floodplain

Lower Long Branch Effective and Proposed 0.2% (500 year) Floodplain

Donaldson Run Conditional Letter of Map Revision

Donaldson Run Effective and Proposed 1% (100 year) Floodplain

Donaldson Run Effective and Proposed 0.2% (500 year) Floodplain

Floodplain Elevation Certificates

An Elevation Certificate is an important tool that documents your building’s elevation. If your home or business is in a high-risk area, your insurance agent will likely need an Elevation Certificate (EC) to determine your flood insurance premium. Floods mean rising water. Knowing your building’s elevation compared to the estimated height floodwaters will reach in a major flood helps determine your flood risk and the cost of your flood insurance. An EC documents the elevation of your building for the floodplain managers enforcing local building ordinance, and for insurance rating purposes.

Arlington Certificates of Elevation