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Downspout Disconnection

Why Should I Disconnect My Downspout?

During heavy rain, every downspout on your home can send 12 gallons of water a minute to the sewer system, which increases the risk of basement backups and sewer overflows. Disconnect and help keep excess water out of sanitary sewers.

Some Downspouts Cannot be Disconnected

You do need enough green space in your yard to drain water into the ground naturally. You cannot create water problems for neighbors or icy conditions on sidewalks, driveways or roads. It's VERY important to check with your municipality to make sure you can legally disconnect and that you disconnect correctly.

Milwaukee Downspout Disconnection Program

Like many cities, the older portions of the City of Milwaukee’s sewer system carry both rain water, also known as clear water, and sanitary sewage in a combined sewer system to be treated by MMSD wastewater treatment plants. A large source of clear water within the combined sewer is from rain that falls on your roof and is collected by downspouts that are directly connected to the sewer system. During rainstorms, this additional clear water can overwhelm sewer pipes and MMSD's treatment plants which can lead to street flooding, basement sewage backups, and sewage overflows directly into our neighboring waterways.

In an effort to reduce the amount of clear water that enters the combined sewer system during rain events, MMSD amended our Rules and Regulations to require the disconnection of downspouts at residential properties of four units or less in the combined sewer service area as long as the disconnections comply with the criteria set forth in the City’s plumbing code and MMSD’s Rules and Regulations. In order to comply with these rule changes, the City of Milwaukee has begun the Milwaukee Downspout Disconnection Program. Check out the DPW tool to see if your home is in the combined sewer service area and read the Downspout Disconnection Program frequently asked questions and incentive program.

How to Disconnect Your Downspout

Follow these steps to safely disconnect your downspout.

Step 1

Contact your city or village to find out if you can legally disconnect.
Step 2

Measure 9" from where the downspout enters the sewer connection.
Step 3

Cut the downspout with a hacksaw.
Step 3

Cut the downspout with a hacksaw.
Step 4

Cap the sewer pipe coming out of the ground. In most cases, you should be able to use a simple rubber cap secured by hose clamp. You can also use a wing-nut test plug.
Step 5

Insert the downspout INTO the elbow (if you put the elbow into the downspout, it will leak). You may need to crimp the end of the downspout with a pair of pliers to get a good fit.
Step 6

Attach a downspout pipe extension to carry water away from the house and foundation. You can use a hacksaw to cut the extension to the desired length. Be sure to insert the elbow into the extension to prevent leaks. Secure the elbow and extension with sheet metal screws. To prevent erosion where the water drains, you can place a splash block at the end of the downspout extension.