Bronx County, New York
USDA's soil survey flags shrink-swell clay on 0% of Bronx County's mapped land and a shallow water table under basements on 9%, both below the national shares of 15% and 29%. None of the county is in drought on the September 22, 2026 Drought Monitor map.
FEMA's flood data list 324 flood losses here since 2016, 73% of them in buildings with basements. 78% of homes were built before 1980, against 50% nationally; the median home dates from 1955.
Data as of September 22, 2026 · sources
expansive clay: shrink-swell limits slab homes
high water table: limits basements
in drought, September 22, 2026
of homes built before 1980
Soil under Bronx County
| Expansive clay (limits slab homes) | 0.0% |
| High water table (limits basements) | 8.6% |
| Septic fields very limited | 64.5% |
| Clay swell (LEP, by area) | 0.9% |
| High-swell land (LEP 6%+) | 0.0% |
| Urban land, not rated | 47.3% |
| Mapped soil | 35,300 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Greenbelt | 10% | n/a |
| Laguardia | 5% | n/a |
| Chatfield | 2% | n/a |
| Charlton | 2% | n/a |
| Ebbets | 1% | n/a |
| Woodbridge | 1% | n/a |
How we count · survey areas NY005 (2025-08-28)
What the numbers mean here
Rain over the 12 months to August 2026: 42.35 in, 4.70 in below the 1991-2020 average year of 47.05 in.
USDA rates 64% of the land very limited for septic absorption fields.
With shrink-swell clay on 0% and a shallow water table on 9% of the land, the soil survey points to neither problem across most of Bronx County; conditions still vary lot by lot.
Drought
0% of the county is in drought (D1 or worse) on the September 22, 2026 map. Part of the county was in drought in 31 of the last 52 weeks; the most was 100% of its area, in 25 weeks, most recently on the July 28, 2026 map.
| Category, September 22, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 0% |
| D1 moderate drought or worse | 0% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
324 flood losses since 2016, $7.2 million paid. The worst year was 2021, with 216. Foundations of the buildings, where recorded: 73% basements, 17% slabs, 1% crawl spaces, 8% elevated. Median water depth outside the building: 10 in.
| Year | Flood losses |
|---|---|
| 2016 | 2 |
| 2017 | 5 |
| 2018 | 18 |
| 2019 | 5 |
| 2020 | 3 |
| 2021 | 216 |
| 2022 | 10 |
| 2023 | 43 |
| 2024 | 19 |
| 2025 | 3 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 47.05 in |
| 12 months to August 2026 | 42.35 in (-4.70) |
| 2025 | 37.04 in (-10.01) |
| Wettest year since 1895 | 2011: 68.40 in |
| Driest year since 1895 | 1965: 29.58 in |
| Days with 1 inch or more, normal at NEW YORK LAGUARDIA AP (5 mi away) | 11.6 |
Homes
| Housing units | 559,415 |
| Median year built | 1955 |
| Built before 1980 | 78% |
| Built 2000 or later | 13% |
| Owner-occupied | 20% |
| Median value, owner-occupied | $529,500 |
| Single-family detached | 7% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| New York County, NY | 8 mi | 0% | 2% |
| Queens County, NY | 13 mi | 0% | 15% |
| Bergen County, NJ | 14 mi | 0% | 26% |
| Hudson County, NJ | 14 mi | 0% | 32% |
| Kings County, NY | 16 mi | 0% | 17% |
| Nassau County, NY | 16 mi | 0% | 18% |
| Essex County, NJ | 21 mi | 0% | 22% |
| Westchester County, NY | 22 mi | 0% | 33% |
Sources: USDA SSURGO (August 28, 2025) · US Drought Monitor (September 22, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status