East Side and Riverwest basements take on water in fall storms for three main reasons: older sewers that carry rain and wastewater in one pipe, gutters and yard drains clogged with leaves, and aging foundations and sewer laterals that let saturated soil push water inside. Most wet basements involve more than one of these.
Both neighborhoods hug the Milwaukee River. The East Side runs between the river and Lake Michigan, and Riverwest sits on the other bank, bounded by the river on its east and south sides.
They are also two of Milwaukee's older residential areas, full of duplexes, bungalows and cottages that have seen a lot of autumns. Knowing where the water came from tells you how to clean it up and how to keep it from coming back.
Why does heavy rain back up into Milwaukee basements?
It backs up when more water enters the sewer than the pipe can carry away. With nowhere else to go, the water rises into the lowest opening it can find, and that is often a basement floor drain.
The City of Milwaukee explains that a combined sewer is a single pipe that collects sanitary flow from homes and businesses along with stormwater from the streets. According to the city, combined sewers serve roughly one third of Milwaukee, in the older parts of town.
On a dry day that single pipe has room to spare. In a downpour it fills quickly. The city also points out how much water comes from private property: a single downspout can deliver up to 12 gallons a minute in heavy rain, and foundation drains can add up to 10 gallons a minute.
Why are fall storms harder on basements than summer storms?
Leaves are the big difference. The same amount of rain causes more trouble in October because the paths that normally carry it away are blocked.
Older neighborhoods like the East Side and Riverwest tend to have big street trees. When those trees drop their leaves, the leaves collect in gutters, cover the grates on street inlets, and pack into the drains at the bottom of outside stairwells.
A gutter full of leaves spills over the edge and dumps roof water right beside the foundation. A covered street inlet lets water pond at the curb and creep toward the lowest driveway or stairwell on the block.
Fall rain also tends to arrive as long, steady soakers. Milwaukee's spring and fall storms often last for hours, which gives the ground time to saturate. Wet soil holds water against basement walls, and it finds every crack.
What is it about East Side and Riverwest homes?
The age and style of the housing play a large part. These neighborhoods were built up generations ago, and many of their lower levels are lived in.
The Encyclopedia of Milwaukee describes how Polish immigrants in Riverwest built modest homes that included basement apartments under single-family and duplex houses, the style known locally as the Polish flat. Some were created by raising an existing house and building a living level underneath.
That history matters when it rains. A lower-level apartment has drywall, flooring, cabinets and someone's belongings sitting at the lowest point in the building, right where water arrives first.
The East Side has its own mix. Its housing ranges from Queen Anne homes to bungalows, two-family duplexes and larger apartment buildings, many dating to the early 1900s. Older foundations may be stone, brick or block, with mortar joints that wear out over time.
Underground, the pipe that connects each house to the city sewer (the lateral) ages too. Old laterals can crack or shift at the joints, and tree roots go looking for those gaps. A partly blocked lateral drains fine on a normal day and fails on the one day it needs full capacity.
How can you tell where the water came from?
Look at where it showed up first and what it looks like. The source decides the cleanup method, so it is worth a careful look before anything is moved.
- Water rising from the floor drain, toilet or laundry sink: a sewer backup. It is often dark and has a strong odor.
- Damp lines where the wall meets the floor, or water weeping through cracks: groundwater seepage from saturated soil.
- Water under a window or at the bottom of an outside stairwell: surface water from a clogged window well or stairwell drain.
- Water in one corner below a downspout: roof runoff from an overflowing gutter or a disconnected downspout.
Take photos of the first spot you noticed and of the high-water line. Those details help a restoration crew and your insurance adjuster understand what happened.
What should you do when you find water in the basement?
Think about electricity before anything else. Do not walk into standing water if outlets, the electrical panel or plugged-in appliances are wet or under water. Shut off power to the basement only if you can reach the panel from a dry spot.
Next, stop adding water to the system. If the floor drain is backing up, hold off on laundry, dishwashing and showers until the storm passes, since anything you send down the drain may come back up.
Then take these steps as conditions allow:
- Photograph the water and the damaged items before you move them.
- Lift what you can carry to a dry floor, starting with papers, photos and electronics.
- Treat water from a sewer backup as contaminated water. Wear waterproof boots and gloves, and keep children and pets out of the area.
- Report the backup to the city's public works department so it is on record.
- Call your insurance company and ask how your policy handles sewer backup and groundwater. Your insurer decides what your policy covers.
How is a flooded basement cleaned and dried?
The process depends on the kind of water, and it always starts with getting the standing water out.
Crews extract the water, then check walls, floors and framing with moisture meters to see how far it traveled. Water wicks upward inside drywall and sideways under flooring, so the wet area is usually larger than it looks.
With clean water, many materials can be dried in place. With contaminated water such as sewage, porous materials that soaked it up are removed instead of dried. That usually includes carpet, pad, the lower section of drywall and insulation behind it.
After removal, the remaining surfaces are cleaned and treated, and air movers and dehumidifiers run until moisture readings return to normal. The EPA advises drying wet areas within 24 to 48 hours to help prevent mold growth, so the clock starts as soon as the water arrives.
What can you do before the next storm?
A few low-effort habits reduce the odds of a wet basement. None of them rule it out, but each one removes a source of water.
- Clean gutters after most of the leaves have fallen, and again in late fall.
- Rake leaves away from the street inlet near your home when it is safe to do so.
- Clear window wells and outside stairwell drains.
- Make sure downspouts release water several feet from the foundation.
- Store basement belongings in plastic bins on shelves instead of in cardboard on the floor.
- Ask a plumber about a camera inspection of the lateral and whether a backwater valve suits your home.
Frequently asked questions about wet basements on the East Side and in Riverwest
Does living close to the Milwaukee River mean my basement will flood?
Not on its own. In a typical fall storm, basement water is more likely to come from the sewer, roof runoff or wet soil than from the river itself.
Can I just use a shop vacuum and fans?
For a small puddle of clean rainwater on bare concrete, yes. If water reached drywall, carpet or a finished apartment, or if it came up through a drain, have it professionally extracted and measured.
How soon does mold become a concern after a basement gets wet?
Quickly. The EPA's guidance is to dry wet materials within 24 to 48 hours, which is why drying should start right away.
Do I have to tear out a finished basement after a sewer backup?
Usually only the materials that absorbed the water. Framing and concrete can generally be cleaned and dried, while soaked carpet, pad and drywall are removed.
Who should I tell about a sewer backup besides my insurance company?
Tell the city. Reports help public works and the sewerage district see where problems cluster during a storm.
If a fall storm has left water in your East Side or Riverwest basement, contact ServiceMaster Kwik Restore to have it extracted, dried and checked for hidden moisture. We are available 24/7.