Statistics
Basement water intrusion statistics
How often water gets into U.S. basements, where it happens most, and how basements compare with other foundations.
Written by HyreFoundation Research Desk Primary-source research and fact checking
The finding
Basement water intrusion statistics from the 2023 American Housing Survey: 6.9% of occupied U.S. homes with a basement had water leak in through the basement in the previous 12 months. That is about 2,621 thousand households. Counting leaks through the roof, walls or windows too, 12.2% of basement homes had some outside water get in.
Basement leaks are most often reported in East North Central (8.5%) and West North Central (8.2%), and least in South Atlantic (3.5%). Mold in the basement was reported by 1% of basement households.
The headline numbers
How common is basement water intrusion?
About one basement home in 14 reports water coming in through the basement in a given year.
The AHS asks every household whether water leaked in from outside in the past 12 months and, if so, where it came in. Of an estimated 37,950 thousand occupied homes with a basement, 6.9% named the basement.
This counts events the household noticed. Dampness, condensation and slow seepage that never shows as water may not be reported, so the true rate of wet basements is likely higher.
Water in a basement usually comes from soil saturated against the wall, pressure under the floor, or roof water dumped next to the foundation. Our pages on hydrostatic pressure and drainage and grading explain the mechanics.
Which regions report the most basement leaks?
Rates run from 3.5% to 8.5% across divisions with enough sample. West South Central has too few basement homes in the sample to publish a rate.
| Census division | Basement leak, last 12 months | Any outside leak | Basement mold | Foundation cracks or crumbling | Share of homes with a basement | Sample basement homes |
|---|---|---|---|---|---|---|
| United States | 6.9% | 12.2% | 1% | 5.2% | 37.7% | 11,780 |
| East North Central | 8.5% | 13% | 1.1% | 5.1% | 71% | 3,608 |
| West North Central | 8.2% | 13.4% | 1% | 5.7% | 73.7% | 1,006 |
| New England | 7.8% | 12.7% | 1.2% | 6.4% | 84.6% | 1,410 |
| Middle Atlantic | 6.7% | 12.2% | 1.1% | 5.2% | 78.1% | 2,266 |
| East South Central | 6.3% | 14% | 0.6% | 7.5% | 20.4% | 271 |
| Pacific | 6.1% | 13% | 1% | 7.8% | 8.6% | 642 |
| Mountain | 4% | 11.1% | 0.1% | 3.7% | 29.5% | 470 |
| South Atlantic | 3.5% | 8.6% | 1.5% | 3.8% | 21.1% | 2,068 |
| West South Central | too few | too few | too few | too few | 1.5% | 39 |
Do basement homes leak more than other homes?
Yes. 12.2% of basement homes reported an outside leak of any kind, against 8% of crawl-space homes and 6.2% of slab homes. A basement is a below-grade room surrounded by soil, so it has more ways to take on water. See crawl space statistics for the other foundation types.
What to do with a wet basement
Start outside: clean gutters, extend downspouts away from the wall, and check that soil slopes away from the house. These are safe homeowner fixes. Then note when water appears (after rain, in spring thaw, all the time) and where (wall-floor joint, cracks, window wells).
Those notes decide the repair. Compare interior vs exterior waterproofing, French drain vs sump pump and basement waterproofing. A wall bowing inward or a crack that is widening is a structural problem first: have a licensed structural engineer look before waterproofing over it.
Method
2023 American Housing Survey national public use file v1.1 (household.csv), retrieved October 27, 2026, with the AHS 2023 Value Labels file for codes.
Occupied units (INTSTATUS 1) with a basement under all or part of the house (FOUNDTYPE 1 or 2). All estimates weighted with WEIGHT.
Basement leak = LEAKOBASE yes (water leaked in from outside through the basement in the last 12 months); households with no outside leak count as no. Any outside leak = LEAKO yes. Mold = MOLDBASEM yes. Foundation cracks = FNDCRUMB yes. Non-responses are excluded from each rate.
Sample survey: division rates carry sampling error and we suppress any rate based on fewer than 100 sample homes. Leaks are household reports for the last 12 months, so a dry or wet year shifts them. No figure here is a cost.
How to cite or embed this data
You may reuse the figures and the CSV with attribution (CC BY 4.0). Link back to this page so readers can see the method.
Citation: HyreFoundation Research Desk. (2026). Basement water intrusion statistics. HyreFoundation. Data from the 2023 American Housing Survey national public use file, retrieved October 27, 2026. https://hyrefoundation.com/statistics/basement-water-intrusion/
Embed snippet (paste under your chart or table):<p>Source: <a href="https://hyrefoundation.com/statistics/basement-water-intrusion/">Basement water intrusion statistics</a>, HyreFoundation analysis of the 2023 American Housing Survey national public use file (retrieved October 27, 2026).</p>
Dataset: /research/basement-water-intrusion.csv, built from the public source named above. Recompute it from the source if you need a later cut.
Questions
What percentage of basements get water?
How many homes have basement leaks each year?
Which region has the most basement leaks?
Is this the same as a damp basement?
Can I download the data?
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HyreFoundation Research Desk
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