Why does sewage come up my Dearborn basement drain when it rains hard?
Older sewers carry sewage and storm runoff in the same pipe, and a heavy storm can fill them faster than they drain. When that happens the pressure pushes water back up the lowest openings in your house, which is usually a basement floor drain. East Dearborn is lower ground and was built before World War II.
Detroit's sewers are largely combined, which is why heavy rain fills basements with sewage in vulnerable neighborhoods across the metro area. Which blocks in Dearborn sit on a combined line and which on separate storm and sanitary pipes varies, and the city's Public Works department is the place to ask about your street. What the city has said about its own flooding is clear enough, though: the storm system was designed for about three inches in 24 hours, and east Dearborn sits lower than the west side and was developed before the war, so its sewers were built to that era's standards.
The city also noted that later infill removed several surface streams that once led toward the Rouge River, leaving the water fewer places to go. In June 2021 the northeast and southeast ends took the worst and most widespread damage. In the August 2014 storm, the combined sewers across Wayne, Oakland and Macomb counties overflowed and basements backed up well beyond Dearborn. A floor drain with no backwater valve is the shortest path from the pipe to your slab.
What gets thrown away after a sewage backup, and what can be saved?
Porous materials that soaked up sewage are discarded because contamination goes deep and cannot be proved clean: carpet, pad, insulation, particleboard, wet drywall and cardboard. Hard, non-porous surfaces such as concrete, block, metal and sealed tile can be cleaned and disinfected, then dried and kept.
The reasoning is physical rather than fussy. A porous material has thousands of tiny channels, and contaminated water travels into them. You can dry the surface and get a normal moisture reading and still have contamination inside, so there is no meter that certifies carpet or insulation as clean. Taking it out is the only way to be sure it is not still in the room.
Contents are judged one at a time. A plastic bin or a metal tool can be washed and disinfected. Upholstered furniture, mattresses, cardboard boxes, books, stuffed toys and soaked papers generally go. Finished basements are the hardest hit: the bottom of the drywall, the baseboard and the insulation behind it are usually cut out to a line above the tide mark, because water wicks up a wall further than it looks like it has.
- Usually discarded: carpet and pad, insulation, particleboard and MDF, wet drywall, cardboard, soaked books and papers, upholstered items
- Usually cleaned and kept: poured concrete, block, metal, glass, sealed tile, solid plastic bins
- Judged case by case: solid wood furniture, framing lumber, hardwood, items with sentimental value
What should I never do after a sewage backup?
Do not wet-vacuum it, mop it with bleach, walk through it barefoot, or let children and pets into the level. Keep the furnace and air handler off if ductwork serves that floor, and do not run the washer or flush. Photograph, call, and wait for protective equipment before removing anything.
Each of these is a common instinct, and each makes it worse.
A household wet vacuum pulls contaminated liquid into a motor and exhausts fine droplets back into the air of the house, and the machine is then contaminated for good. Bleach and a mop spread the problem across a bigger area of porous floor and leave a smell of clean over a loss that is not clean. Running the furnace or air conditioner with ductwork in or near the affected level circulates air from that level through the house, so it is switched off until a technician has looked at it.
- Do not use a wet vacuum, a household mop or a sponge on sewage
- Do not mix bleach with other cleaners, and do not treat bleach-and-mop as disinfecting porous materials
- Keep children, pets and anyone with a weakened immune system out of the level
- Do not step into water near outlets, a panel or appliances; if it is touching them, stay out
- Turn off the HVAC system if its returns or ducts are in the basement, and keep the doors to that level closed
- Do not run washers, dishwashers or flush toilets until the line is clear
Is sewer backup covered by homeowners insurance in Michigan?
Often not on its own. The Michigan Department of Insurance and Financial Services says water and sewer backup is not automatically covered by a homeowners or renters policy, and a water-backup endorsement is a separate add-on. Flood insurance is a different policy again. Your insurer decides coverage, so read your policy and ask your agent.
This is the question most Dearborn-area homeowners ask second, after the one about the smell. The state regulator's advice is to discuss a backup option with an agent before a flood, because it is not automatic. It also says that when you report damage you should not simply call it a flood: storm rainwater coming in, a sewer backup and a failing sump pump are different causes that a policy can treat differently. Federal flood insurance is a separate policy and typically takes about 30 days to go into effect, so it cannot be bought after the storm is forecast.
What the crew can do is document the loss clearly: photos before anything moves, moisture readings and a written scope. Whether any of it is paid is decided by your insurer under your own policy, and nothing here is a promise of coverage. If you are unsure which of your policy's headings applies, call your agent early and describe what happened in plain terms.
Is the backup the city's sewer or my own line?
A backup that hits during a storm, on a block where neighbors are flooding too, points at the street sewer. A backup on a dry day, in one house, points at the private lateral. A plumber's camera inspection settles it. That decides who is responsible for the repair, but not how soon the water needs to be cleaned up.
Do not wait for a diagnosis before cleanup begins. Sewage sitting on porous materials does not improve while the question is argued, and the cleanup is the same either way. Call the city's Public Works office to report a surcharge on your block, since a record of the event helps if the city has any program or inquiry open. For a clog, a collapsed pipe or a missing backwater valve, you will need a licensed plumber, and that is outside what the crew does.
If your house sits in a Detroit neighborhood such as Warrendale or the Far West side, the Detroit Water and Sewerage Department runs a Basement Backup Protection Program that helps with valves and sump pumps. It is for Detroit addresses only. A Dearborn address does not qualify for it, so a Dearborn homeowner should ask a plumber about a backwater valve directly.
