City of Alexandria, VA
Flooding Information For information on hurricanes and tropical storms, visit the hurricane preparedness page.
Alexandria’s low elevation and its proximity to the Potomac River make it susceptible to flooding. Nearly every year, and sometimes several times throughout the year during periods of heavy rain, hurricanes or quick snow melts, residential and commercial properties are threatened with the potential of tidal and wind-driven flooding from the Potomac River and/or low-land flooding, particularly in neighborhoods around Four Mile Run. We encourage residents and business owners to plan for flooding as part of their emergency preparedness planning.
Here are standard definitions for typical weather advisories that are issued when flooding is expected:
Flash Flood Watch: Issued to indicate current or developing hydrologic conditions that are favorable for flash flooding in and close to the watch area, but the occurrence is neither certain or imminent.
Flash Flood Warning: Issued to inform the public, emergency management, and other cooperating agencies that flash flooding is in progress, imminent, or highly likely.
Heavy rains, which typically occur during hurricane season, sometimes cause sewer backups in some parts of Alexandria, especially near Commonwealth Avenue. The City urges residents to take necessary precautions. With many hours of heavy rain, sewer line may fill up with water and some sewage. Because of this, the sewer system may approach its carrying capacity and may overflow in some areas. It may also back up into homes through floor or plumbing drains.
There are several steps you can take to help prevent sewage backup into your home.
After the rain stops, if sewage has come through a floor or plumbing drain, open the drain to allow as much water to drain out as possible; use buckets, sump pump or other means to remove as much of the contaminated water as possible.
For more information, call 703.746.4800.
When there is a high risk of flooding, the City will often make sandbags available to residents and businesses. For several years, the City of Alexandria’s Department of Transportation and Environmental Services (T&ES) has operated a flooding prevention program that included the limited provision of sandbags to affected business and residential areas.
Proper Use of Sandbags
The use of sandbags is a simple, but effective way to prevent or reduce floodwater damage. Sandbags can act as a barrier to divert moving water around instead of through buildings. Sandbag construction does not, however, guarantee a watertight seal.
Do not rely on sandbags alone to protect your property. Use baffle boards (plywood sheeting) or sheets of plastic tarp with sandbags. When the threat of flooding is over, sand can be recycled into your garden as a soil amendment and the bags should be thrown away.