Planting a rain garden and a downspout disconnected into the garden

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 sewer water backing up into basements and overflowing into our waterways. Disconnect and help keep excess water out of sanitary sewers.

Like many cities, the older portion of the City of Milwaukee and the Village of Shorewood is served by combined sewer systems that carry rainwaters, also known as clear water, and household wastewater to the Metropolitan Milwaukee Sewerage District's (MMSD) treatment facilities.

A significant 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 combined sewer system. During rainstorms, this clear water can overwhelm sewer pipes and MMSD's treatment plants, leading to street flooding, basement backups, and sewage overflows directly into our waterways.

Some Downspouts Cannot be Disconnected

You'll need enough green space in your yard to drain water into the ground naturally. You want to avoid creating water problems for your neighbors or icy conditions on sidewalks, driveways, or roads. It's VERY important to check with your municipality to ensure you can legally disconnect and disconnect correctly.

Downspout Disconnection Programs

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. To comply with these rule changes, the City of Milwaukee has begun the ​​​​​Milwaukee Downspout Disconnection Program and the Village of Shorewood Downspout Disconnection Program. Check out Milwaukee's DPW tool to see if your home is in the combined sewer service area and read the Downspout Disconnection Program frequently asked questions.

How to Disconnect Your Downspout

Follow these steps to safely disconnect your downspout. 

  • Step 1

    Step 1

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

    Step 2

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

  • Step 3

    Step 3

    Cut the downspout with a hacksaw.

  • Step 3

    Step 3

    Cut the downspout with a hacksaw.

  • Step 4

    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

    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

    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.


What You Will Need to Disconnect     

MMSD Downspout Disconnect Tools
  • Hacksaw
  • Tape measure
  • Hammer
  • Screwdriver
  • Pliers
  • Sheet metal screws
  • Downspout elbow
  • Downspout extension
  • Splash block (optional)
  • Rubber Cap

Learn how to disconnect your downspout with Melinda Myers.


Help Us Manage Water Where it Falls

Rain Garden in a yard

Plant a Rain Garden

Rain gardens help reduce sewer overflows and water pollution by absorbing stormwater runoff from hard surfaces into the ground naturally. Learn how to plant a rain garden and help protect Lake Michigan.

Install a Milwaukee Rain Barrel

Install a Rain Barrel

Get FREE water by the barrel from your roof and use it when it’s dry outside to use in your landscape.  Rain barrels help keep excess water out of the sewer system and help reduce water pollution. 

MMSD Water Drop Alert

Text: WATERDROP to 414-296-4422 for Española texto GOTADEAGUA a 414-296-4422

Receive Water Drop Alert text messages when heavy rain threatens the area. When a Water Drop Alert has been issued, a reminder is sent to use less water.

What do you do when an alert is issued?

  • Hold off on washing dishes and laundry
  • Take a shorter shower 
  • Empty your rain barrel