Raising Basement Appliances Above Flood Level in Washington, DC

Washington floods in two different ways. Along the Potomac and Anacostia, and along streams like Watts Branch in Ward 7, low-lying land sits in mapped floodplains. Across much of the older city, intense summer storms overwhelm sewers and push water up through basement floor drains, which is what Bloomingdale and LeDroit Park residents lived through in 2012. Either way, the washer, dryer, water heater and furnace in the basement are usually the first things to go.

Raising that equipment above the expected water level is one of the more practical defenses. This guide covers what appliance manuals say, what FEMA recommends, how DC regulates the work, and how to judge your own basement.

What the guidance says

The manufacturer. No appliance manual can tell you how high water gets in your basement, so none sets a flood height. They do set the baseline: Whirlpool's electric dryer guide rules out installing or storing the dryer in a spot exposed to water or weather.

FEMA. In Chapter 8 of its Homeowner's Guide to Retrofitting, "Protecting Service Equipment," FEMA's position is that shallow flooding, 1 to 2 feet over a basement or garage floor, can be handled by setting furnaces, water heaters and appliances on concrete or masonry block platforms. It advises adding a minimum of 1 foot of freeboard, meaning extra height, to your Flood Protection Elevation. The deeper the expected water, the less room is left above it, and once it reaches close to the ceiling, raising things in the lower level stops being an option; the equipment has to move or be protected where it is. FEMA also says a design professional must determine expected wind and earthquake forces on elevated equipment, and that your contractor should check with utilities about any restrictions on elevating their equipment.

Sewer backup. The same chapter explains that flooding can overload sanitary and combined sewers so water flows backward out of floor drains and toilets, and that the usual solution is a backflow valve. It notes that installing backflow valves and other plumbing changes is usually regulated by local building codes and should be done by a licensed plumber.

How DC regulates flood-zone work

• •The agency. DC's floodplain regulations, the Flood Hazard Rules in Title 20 DCMR Chapter 31, are managed by the Department of Energy and Environment (DOEE). Construction codes are administered by the Department of Buildings (DOB).
• •Interior work counts. DOEE's 2024 technical guidance on interior work says the Flood Hazard Rules apply to all development in the Special Flood Hazard Area, including interior work that isn't a substantial improvement. Its examples include repair, replacement or new installation of mechanical, electrical or plumbing systems such as a furnace, electrical outlets or water lines. The rules call for gas lines, electrical equipment and meters to be located and elevated, wherever possible, to minimize flood damage.
• •The target height. The same guidance describes DC's design flood elevation under the 2017 Construction Codes as 2 feet above the base flood elevation or the 500-year flood elevation, whichever is higher.
• •The map. DOEE links to the DC Flood Risk map, where you can search an address and view FEMA flood zones, 100-year and 500-year flood areas, stormwater flooding layers and whether the property is on the combined sewer system.

Rules change, and DOEE expanded its regulated flood hazard area in 2025. Check the current requirements with DOEE (flood.risk@dc.gov is the contact in its guidance) before planning work in a mapped floodplain.

Which parts of DC to think hardest about

DOEE has identified Southwest and Buzzard Point as at risk from the Potomac and Anacostia rivers and from extreme rain, and has studied revised floodplain mapping along Watts Branch through neighborhoods such as Deanwood and Kenilworth. Low ground near the Anacostia and downtown areas around Federal Triangle also show up in the District's flood risk work. For sewer backup, the risk is spread across the older, combined-sewer part of the city rather than tied to a river.

Assessing your basement

1. Find your high-water mark. Look for stains on walls and stair stringers, ask previous owners or neighbors, and check whether the basement has flooded from a floor drain before.
2. Look up the property on the DC Flood Risk map to see whether it's in a mapped flood zone and what flood elevation applies.
3. Set a target. Take the expected flood level and add at least a foot, as FEMA suggests. In a mapped zone, use DOEE's design flood elevation instead.
4. Measure each appliance: the base, the control panel, the outlet it plugs into and where its gas, water and vent connections sit.
5. Check the ceiling height. Many rowhouse basements are low. A washer on a 16-inch block platform with a dryer stacked above may not fit, and machines still need their own clearances.
6. Look at the floor drain. If sewer backup is your main risk, a backwater valve may do more than raising the machines.

Practical approaches

• •Masonry platforms for a washer, dryer or water heater when expected water is shallow, per FEMA.
• •Relocating laundry upstairs when water could reach most of the basement's height. Compact or stacked machines in a closet are common in DC for this reason.
• •Raising outlets and circuits above the target height so the machines can be plugged in without cords running through the danger zone.
• •A backwater valve on the building sewer. DC Water has offered a backwater valve rebate program; check its current terms before you start, since eligibility and amounts have changed over the years.

After water gets in

Don't step into a flooded basement if water may have reached outlets, cords or appliances that are still energized. Once the power is off and the water is out, don't restart a washer, dryer or water heater that sat in floodwater. None of the motors, control boards or wiring harnesses in these machines are built to survive being underwater, and gas valves and burners that have been underwater need inspection before use. Floodwater from sewer backup is also contaminated, which affects pumps, seals and insulation.

Who does the work

• •Moving outlets or circuits above flood level is licensed electrical work; in DC, trade permits are pulled by a DC master licensed professional.
• •Backflow valves and relocated water or drain lines are licensed plumbing work.
• •Relocating gas appliances such as a dryer or water heater is licensed gas fitter work.
• •Elevated platforms for heavy equipment should be designed with the forces FEMA describes in mind.

Any appliance that sat in floodwater should be inspected before it runs again. We service washers and dryers across Washington, DC; see our service areas. If laundry moves to a garage or porch to stay dry, read about temperature limits in unheated spaces.

Documents referenced

• •FEMA: Homeowner's Guide to Retrofitting, Chapter 8, Protecting Service Equipment: masonry platforms for shallow flooding, freeboard, design professional review, backflow valves.
• •DOEE: Regulation of Interior Work Inside a Floodplain (May 2024): interior work subject to the Flood Hazard Rules, design flood elevation, utilities.
• •DC Flood Risk map: address lookup for flood zones and sewer system type.
• •DC Water: Backwater valve information: rebate program details.
• •Whirlpool 29-inch electric dryer installation instructions W10617663C: keep the dryer away from water and weather.