Wednesday, August 15, 2012

DC Water: New guide to preventing home flooding during storms

See this tweet from DC Water that just came out:
DC Water‏@dcwater

#BloomingdaleDC #LeDroitPark New guide to preventing flooding (PDF). Also distributed by our engineering consultants.

Here is the title of this document:


And here are the text portions of this document (note that several images are throughout the PDF):

Flooding can damage District homes and businesses. It results when the volume of water runoff from a storm is greater than what the storm system around your property can handle. When this occurs, overland flow of stormwater enters your building through an opening such as a door, a window, or a crack in the building foundation.

DC Water recommends three basic approaches to home flood control:

• Keep the water out
• Keep the water away
• Keep your system working

Keep the Water Out

If stormwater is flooding your building through a window, under a door, or through a stairwell entrance way, consider building a small barrier around these entry points.
Examples of these barriers are:
Window Wells

Designed to create an opening around your basement window, window wells are below ground level, U-shaped, and may be brick or manufactured from rust resistant metal. To keep rain, snow, yard waste, animals and people from falling into the well, seal them with watertight window well covers.
Raised Steps

As shown in the photo, building raised steps in front of your lowest level entrance will keep the water out.
Sand Bags

By diverting moving water away from buildings, properly filled and placed sandbags can be an effective method of preventing flood damage. Untied burlap bags filled halfway with sandy soil and positioned tightly against one another can be placed in appropriate locations such as basement stairways and window wells. Never use bags to build a fortress around your property. This can trap water between the sandbags and the building, causing even further damage.     

Ready-Made Products

There are numerous products on the market made to keep the water out. They include various door barriers, wall barriers, and various alternatives to sandbags. Check your local hardware stores or the many online options.

Keep the Water Away

You want to keep water away from your foundation so it doesn’t seep in through cracks, joints, cinder blocks, or around pipes going through the outside walls. Ways to do this include the following:

Sump Pump System

A sump pump consist of five components: an electric pump, buried outdoor collection piping, discharge piping, a water level sensor, and an electric supply.  The pump sits in a pit that is installed under the basement floor slab. The outdoor drain piping collects stormwater under and around the house foundation and directs flow to the sump pit.  As the water in the pit rises, the water level sensor activates the pump. The pump sends water through the discharge piping to outside the house. The end of the discharge piping must be directed away from your foundation.

The sump pump and its components need to be installed by a DC licensed contractor. Routinely check the sump pump to ensure it is plugged in and the breaker is on. During a power outage, the sump pump will not work unless it has a backup power source.

Gutters, Downspouts, Downspout Extension, and Splash Pads

Gutters, downspouts, downspout extensions, and splash pads are important parts of any home or business drainage system and are essential for sending roof runoff away from the building. Gutters catch the water that runs off the roof and channel it into downspouts, which direct the flow of water to the ground. Downspouts need to direct the flow away from your foundation. Splash pads and down spout extensions help to keep water away. Splash pads are typically about two feet long and made of concrete or plastic. A downspout extension comes in different materials and lengths to fit the need of your yard.      

In older areas of the District, the sewer system is combined. This means that one sewer pipe carries both sanitary wastewater and stormwater flow. In this part of the District, downspouts are often directed into the ground and connect to the house sewer lateral. If the end of your downspout is buried, the use of a splash pad or downspout extension would not apply.         

Yard Grading

The ground closest to the house should slope down and away from your building to keep water from seeping into the basement or flooding the foundation.  However, keep soil at least eight inches away from wood siding to protect against rot and insects.

Sealing Cracks

This helps to make your building more waterproof and structurally sound. Make sure that the wall or floor surface is properly prepared and that you use a product specifically developed for the type of surface you are sealing – concrete, brick, wood, tile or others.

Keep Your System Working

DC Water recommends that you regularly complete necessary maintenance on your home or business drainage system. This includes keeping outside drains, gutters, and downspouts free of leaves, litter, and trash.         

If sewage is backing up in your home, call DC Water immediately on its 24-hour Water and Sewer Emergency Line at (202) 612-3400. An inspector will be dispatched to investigate the public sewer and determine the cause of the backup. If the public sewer is clear, you will be advised to call a DC licensed plumber and have your private sewer service line cleared.
Sewage Backups: Another Possible Flooding Source
Floor Drain Backwater Valve/Plug

If your only source of sewage backup is a floor drain or outdoor stairwell drain, then you may be able to install a simple floor drain valve to stop this problem. This is an inexpensive way to protect your home from flooding. As the water backs up, the water pushes the plug up and keeps the water from flowing. Once the water recedes, the plug drops back down and the floor drain can be used again.

Backflow Prevention Devices

If you live in an area with a combined sewer system and are prone to sewer backups you should consider installing a Backflow Preventer (BFP), also called a Backwater Preventer. This device can effectively shut off the home or business from the combined sewer system during storms. Automatic and manual BFPs are available. When the BFP is actively working, you must not use the toilet, sink, shower, washer, dishwasher or any appliance that discharges wastewater. BFPs need to be installed by a DC licensed plumber. If you have a BFP installed, be sure to inspect and clean it regularly.

Flood Insurance –
An Extra Measure of Protection

Although flood insurance is relatively inexpensive, most people do not purchase protection. Homeowner insurance policies do not cover flood damage. DC Water recommends property owners consider the purchase of a policy or rider to your existing policy that covers the damage and cleanup cost that can result from flooding. Learn more about the National Flood Insurance Program at

DC Water and Sewer Emergency Line (202) 612-3400
DC Water Office of Risk Management  (202) 787-2052
DC Homeland Security and Emergency Management Agency  (202) 727-6161
Mayor’s Citywide Call Center  (202) 727-1000
Federal Emergency Management Agency (800) 621-3362
National Flood Insurance Program  (888) 379-9531

5000 Overlook Avenue, SW | Washington, DC 20032
George S. Hawkins, General Manager

1 comment:

Anonymous said...

Sewage backup
DC Water recommends three basic approaches to home flood control is hintful on what to do during emergency.