Your basement backed up. Here is what to do, and the 45-day clock you cannot miss.

1. Before you clean up

The first hours decide what you can recover, so move in this order.

• Stay safe. Do not enter standing water if the power is on in the basement, and leave and call your utility if you smell gas. See our step-by-step guide on what to do when your basement floods.
• Report it right away and get a reference number. Call whoever runs your sewer the day you find the backup. In Detroit, call DWSD at (313) 267-8000 (or use the Improve Detroit app) and ask for a Service Request number. Detroit requires that number before you can file a claim.
• Document everything before you throw anything out. Dated photos and video of the water line and the damage, an inventory of ruined belongings, and every receipt. Both the city claim and any insurance claim turn on documentation.
• Write down the date you discovered it. That date starts the 45-day clock.

2. Who to file the claim with

It depends on who owns the sewer that backed up. The simplest way to find out is to look at your water and sewer bill and see which agency you pay. Then send written notice to that agency within 45 days of discovery. The deadline is the same everywhere. Only the address and the first phone call change.

The deadline and the rules come from Michigan's sewage-disposal-system-event law, MCL 691.1419. This page is general information, not legal advice. Confirm your own deadline and process with the agency.

3. Filing on time does not guarantee you get paid

Meeting the deadline only preserves your right to be considered. To actually win one of these claims, you generally have to show the sewer system had a defect the agency knew or should have known about, and that the defect was at least 50 percent of the cause of the backup. When a storm is extreme, agencies often argue the rain, not a defect, was the cause. After the June 2021 storms, the Great Lakes Water Authority denied roughly 24,000 claims on exactly that basis. File on time to protect your rights, and at the same time pursue insurance and prevention below, because those are often where homeowners actually recover. See our full DWSD/GLWA step-by-step for exactly what to file and what your realistic odds are.

4. Insurance: the gap most people find out about too late

Two surprises catch metro Detroit homeowners every storm season.

Standard homeowners insurance does not cover sewer or drain backup unless you have added a specific "water backup" or "sewer backup" endorsement, which is usually inexpensive (often roughly $40 to $160 a year). If you do not know whether you have it, you almost certainly do not. See our full sewer-backup insurance breakdown for what the endorsement actually costs and covers in 2026.

Flood insurance is a separate thing again. The federal flood program (NFIP) does not cover sewer backup either, and its basement coverage is limited: it generally excludes finished-basement improvements like flooring and drywall, and most belongings stored below grade. And a low FEMA flood-zone rating does not mean low risk, nearly a third of national flood-insurance claims come from outside high-risk flood areas. Before the next storm, pull your declarations page and read our guide on whether homeowners insurance covers basement flooding in Michigan.

5. Help paying for prevention (Detroit homeowners)

These are the two Detroit doors. Every metro program, including Oakland County rebates and tri-county plumbing help, with its live status and checked date, is tracked in our assistance-programs guide.

If you own a home in the City of Detroit, two city programs may help pay to prevent the next backup. Availability changes, so confirm the current status and your eligibility on the city's own pages.

Private Sewer Repair Program (open, income-qualified)

This program is currently accepting applications on a rolling basis. A March 2025 expansion widened it to 97 Detroit neighborhoods, nearly half the city, backed by $43 million in HUD disaster-recovery funds. At no cost to the homeowner, it can inspect and repair your private sewer lateral, disconnect downspouts, and where needed add a backwater valve or sump pump. It is income-qualified (at or below 80 percent of the Area Median Income), requires showing your home was affected by the June 2021 flood, and the property cannot be in a floodplain. Check your address and apply on the city's Private Sewer Repair Program page.

Basement Backup Protection Program (currently waitlisted)

This program installs backwater valves and sump pumps at no cost for owners in a set of eligible neighborhoods. Applications for its current phases are closed and will reopen only if new funding arrives, but it is worth checking the city's Basement Backup and Flood Protection page for status and to join a waitlist.

Prevention basics for any home

The city recommends disconnecting downspouts from the sewer and, where needed, installing a backwater valve and a sump pump, especially in areas with a history of backups. What a valve costs to retrofit and who actually needs one is covered in our 2026 backwater valve guide. The free city Basement Backup and Flood Protection resources and our guide on what actually keeps a Michigan basement dry walk through what helps most, and roughly what it costs.

When heavy rain is on the way, our live Basement Backup Watch shows active flood alerts, the 48-hour outlook, and river levels for Wayne, Oakland, and Macomb in one place.

Official sources

• City of Detroit DWSD, damage claims and sewage backups
• Michigan Legislature, MCL 691.1419 (Public Act 222 notice requirement)
• Oakland County Water Resources Commissioner, basement flooding claim
• Macomb County Public Works
• Great Lakes Water Authority, glwater.org
• City of Detroit, Private Sewer Repair Program and Basement Backup and Flood Protection
• FEMA / NFIP, flood risk and zones

Basement Risk Check is an independent homeowner resource, not affiliated with or endorsed by the City of Detroit, any county, the Great Lakes Water Authority, FEMA, or any insurer. This page is general information, not legal, insurance, or financial advice. Deadlines, programs, and processes change. Confirm current details with the relevant agency before you act, and consult a licensed attorney or insurance professional about your specific situation.

Frequently asked questions