Garden units and basement condos are a fixture of Chicago’s housing stock, and they come with a water-related insurance question that’s easy to get wrong: sewer backup and overland flooding are not the same thing, and your policy treats them completely differently.
Two Kinds of Water, Two Kinds of Coverage
Standard condo insurance excludes flood damage entirely, full stop. What most garden and basement unit owners actually need to understand is the split between two separate coverages:
| Water Source | What Covers It |
|---|---|
| Water backing up through a drain, toilet, or sewer line | A sewer backup endorsement added to your condo policy |
| Water entering from outside, rain, river overflow, surface flooding | A separate flood insurance policy, typically through the NFIP or a private flood carrier |
Chicago sees far more of the first kind than the second. According to the Federal Reserve Bank of Chicago, the overwhelming majority of flood-related claims in the city stem from basement flooding caused by heavy rain overwhelming the sewer system, not rivers or lakes overflowing their banks.
Why This Distinction Actually Matters
A standard condo policy with no endorsements covers neither of these events. A sewer backup endorsement typically adds coverage in the range of $5,000 to $25,000, enough for a basement seepage event but not necessarily a major loss. A true flood policy, purchased separately, covers a different category of damage entirely, and even then, coverage for basement-level personal property is limited under NFIP rules, generally restricted to fixed items like furnaces and water heaters rather than furniture or electronics.
What This Means If You Own a Garden Unit
- Ask specifically whether your condo policy includes a sewer backup endorsement, not just standard water damage coverage
- Understand that a separate flood policy addresses overland water, a different and less common event in most Chicago neighborhoods
- Know that flood policies limit basement personal property coverage regardless of which policy type you carry
- Check whether your HOA’s master policy addresses shared basement infrastructure, like boilers or electrical panels, separately from your unit
A Detail Worth Bringing to Your Agent
Because most Chicago basement flooding is a sewer backup issue rather than a true flood, many garden unit owners find that a strong sewer backup endorsement matters more day-to-day than a separate NFIP policy, though both are worth discussing given the city’s aging infrastructure and increasingly heavy rain events.
This is a genuinely different conversation than the one we’ve had about high-rise master policies, including our post on understanding master policies for high-rise condo owners, since garden and basement units face a specific water-related risk that upper-floor units simply don’t.
Skylight Insurance helps Chicago garden and basement condo owners sort out sewer backup endorsements versus flood coverage before the next heavy rain event. Visit Skylight Insurance or call 844-475-9467.


























