Sewer backup after heavy rain in Michigan: what to do and who to tell

Why basements back up when it rains hard

A sewer backup and a flooded basement look alike from the stairs and are different problems. In a backup, sewage or wastewater comes up through a floor drain, toilet or tub because the pipe downstream is full or blocked. In a flooded basement, groundwater or surface water gets in through walls, floors or window wells, often because a sump pump stopped. The cleanup, the likely cause and the insurance questions all differ, so work out which one you have before you call anyone.

The Michigan State Police’s flood mitigation brochure says something that surprises people: basement flooding happens more often from sump pumps failing in power outages than from sewer water backing up. If your sump is dead, start with the guide on a sump pump failing in spring.

Southeast Michigan has shown how fast it can go. On August 11, 2014, the National Weather Service in Detroit recorded historic rainfall, with 4 to 6 inches falling over four hours in Wayne, southern Oakland and Macomb counties. Over June 25 to 27, 2021, a stalled boundary brought 3 to 5 inches of rain across Metro Detroit, locally 6 to 8, and flooded basements were reported on June 26, mainly in Wayne and Washtenaw counties. The Michigan State Police emergency management division’s page on that response says the State Emergency Operations Center was activated on June 26, 2021.

The first hour

Stay out of standing water if you can, and ask the plumber and your local health department what precautions they advise for sewage. If water is near the electrical panel or outlets, do not wade in. Stop running water in the house, because every flush and load of laundry sends more down the same pipe.

Then make two calls: one to a plumber, to learn whether the problem is on your side of the line, and one to your insurance agent. Photograph the water level, the drain it came from and anything damaged before you move things. Our emergency plumber page explains how we match requests, and the sewer line repair page covers what a camera inspection shows.

What insurance does and does not say

The Michigan Department of Insurance and Financial Services says flood damage is typically not covered unless you have flood insurance, and that water and sewer back-up is not automatically covered under a homeowners or renters policy. It urges you to talk to an agent before damage occurs. The National Weather Service says the same about flooding and standard policies, and the State Police flood facts sheet adds that sump pump and water backup coverage is optional, with limits and terms that vary by insurer.

One piece of DIFS advice is worth keeping. When you report the loss, say there is water damage and name the cause rather than just saying flood, because a cause such as sewer back-up or a failing sump pump may be covered under the policy. Read yours for a water backup endorsement.

Claims against a city, county or sewer authority

Some backups come from the public system rather than your pipe, and Michigan law gives you a route to a claim, with limits. The statute defines a sewage disposal system event as an overflow or backup of a sewage disposal system onto real property. It excludes events where a substantial proximate cause is an obstruction in a service lead not caused by a government agency, or a connection on your property such as a sump, building drain or downspout.

The deadline is what people miss. MCL 691.1419 requires written notice within 45 days after the damage was discovered, or reasonably should have been, and a suit cannot start until 45 days after the agency receives notice if there is no agreement. The notice must give your name, address and phone, the property address, the date of discovery and a brief description. According to a summary of its page, Oakland County’s Water Resources Commissioner states the same 45-day rule for basement backup claims in its county. This is general information, not legal advice, and an attorney can tell you how the rule applies to your facts.

What some Michigan cities do about it

Local programs differ widely and some change often, so treat the following as examples to ask about.

Royal Oak says it belongs to the George W. Kuhn Retention Treatment Basin drainage program, aimed at reducing flooded basements, and names the private sewer lead, with problems like tree roots, grease and diapers, as a key backup cause. Its street flooding line is (248) 246-3300. See our Royal Oak page.

Detroit’s water department has run a Basement Backup Protection Program that offers a backwater valve, sump pump and downspout disconnection to owner-occupied homes in 11 selected flood-prone neighborhoods, after a camera inspection of the lateral. Sources disagree on whether homeowners pay a deposit, and we could not confirm whether the program is open now, so ask the department first. See Detroit.

East Lansing reimburses backflow prevention equipment at 100% of the first $1,000 and 75% above that, capped at $3,000 per property, and wants an itemized invoice, proof of payment, a city plumbing permit and a passed final inspection. That comes from a summary of the city’s page, so confirm it. See East Lansing.

Grand Rapids runs a Footing Drain Disconnection Program that pays reasonable costs up to $4,500 for eligible homeowners to disconnect stormwater and groundwater inflows from the sanitary lateral, including a sump, backup pump and backwater valves where needed. The city commission set that cap and it may have changed. See Grand Rapids.

Dearborn received more than $8.1 million in FEMA funding for sewer upgrades and basement-backup prevention in east Dearborn, including about 6,200 feet of new storm sewers. After the 2021 flood the city advised cleaning house traps, extending downspouts and calling the Sewer Department at 313-943-2042. See Dearborn.

Backwater valves and sump discharge

The State Police flood facts advise adding a sump pump and sewer backflow valves. A backwater valve closes the house drain when the sewer flows backward. Ask your local building department whether yours needs a permit before you hire anyone, and use a licensed plumber.

Where a sump discharges matters to everyone on your block. Midland’s city code, in force since 1987, makes it illegal to connect a footing drain to the sanitary sewer, and the city names sump discharge into the sanitary system as a backup risk. No statewide ban exists to cite; this is city ordinance, so check yours.

After the water is gone

Keep the paperwork: photographs, the plumber’s findings, the date you discovered the damage and every call you made. If the plumber traces the cause to your own lateral, the guide on main sewer line replacement cost explains permits, MISS DIG and what we can say about price. If the cause is a sump, see sump pump repair.