Baltimore County, Maryland
A shallow water table limits basements on 23% of Baltimore County's mapped land. Shrink-swell clay limits houses without basements on 2%.
12.1% of the county is in drought on the October 13, 2026 Drought Monitor map, down from 13.1% a week earlier. FEMA's flood data list 281 flood losses here since 2016, 38% of them in buildings with basements. 59% of homes were built before 1980, against 50% nationally; the median home dates from 1973.
Data as of October 13, 2026 · sources
expansive clay: shrink-swell limits slab homes
high water table: limits basements
in drought, October 13, 2026
of homes built before 1980
Soil under Baltimore County
| Expansive clay (limits slab homes) | 1.5% |
| High water table (limits basements) | 23.4% |
| Septic fields very limited | 67.3% |
| Clay swell (LEP, by area) | 2.1% |
| High-swell land (LEP 6%+) | 1.5% |
| Urban land, not rated | 10.7% |
| Mapped soil | 394,025 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Glenelg | 16% | 0% |
| Manor | 14% | n/a |
| Glenville | 7% | n/a |
| Brinklow | 6% | n/a |
| Gaila | 3% | n/a |
| Codorus | 3% | n/a |
How we count · survey areas MD005 (2025-09-09)
What the numbers mean here
On 23% of Baltimore County's mapped land, soil stays saturated within about 6 feet of the surface for part of the year, which is basement depth.
Rain over the 12 months to August 2026: 36.94 in, 10.53 in below the 1991-2020 average year of 47.47 in.
USDA rates 67% of the land very limited for septic absorption fields.
Drought
12.1% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 44 of the last 52 weeks; the most was 100% of its area, in 24 weeks, most recently on the July 28, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 99.7% |
| D1 moderate drought or worse | 12.1% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
281 flood losses since 2016, $4.4 million paid. The worst year was 2024, with 109. Foundations of the buildings, where recorded: 38% basements, 18% slabs, 19% crawl spaces, 25% elevated. Median water depth outside the building: 12 in.
| Year | Flood losses |
|---|---|
| 2016 | 35 |
| 2017 | 4 |
| 2018 | 54 |
| 2019 | 7 |
| 2020 | 15 |
| 2021 | 32 |
| 2022 | 5 |
| 2023 | 11 |
| 2024 | 109 |
| 2025 | 7 |
| 2026 to date | 2 |
Rain
| Average year, 1991-2020 | 47.47 in |
| 12 months to August 2026 | 36.94 in (-10.53) |
| 2025 | 40.15 in (-7.32) |
| Wettest year since 1895 | 2018: 73.18 in |
| Driest year since 1895 | 1930: 23.74 in |
| Days with 1 inch or more, normal at BALTIMORE WASH INTL AP (19 mi away) | 10.9 |
Homes
| Housing units | 350,821 |
| Median year built | 1973 |
| Built before 1980 | 59% |
| Built 2000 or later | 14% |
| Owner-occupied | 66% |
| Median value, owner-occupied | $349,300 |
| Single-family detached | 47% |
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 |
|---|---|---|---|
| Baltimore city, MD | 10 mi | 5% | 18% |
| Harford County, MD | 18 mi | 5% | 29% |
| Howard County, MD | 21 mi | 1% | 24% |
| Carroll County, MD | 23 mi | 0% | 21% |
| Kent County, MD | 30 mi | 0% | 54% |
| Anne Arundel County, MD | 31 mi | 0% | 46% |
| York County, PA | 34 mi | under 1% | 20% |
| Cecil County, MD | 37 mi | 2% | 38% |
Sources: USDA SSURGO (September 9, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status