Carroll County, Maryland
A shallow water table limits basements on 21% of Carroll County's mapped land. Shrink-swell clay limits houses without basements on 0%.
66.6% of the county is in drought on the October 13, 2026 Drought Monitor map, down from 97.8% a week earlier. FEMA's flood data list 27 flood losses here since 2016. 44% of homes were built before 1980, against 50% nationally; the median home dates from 1983.
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 Carroll County
| Expansive clay (limits slab homes) | 0.0% |
| High water table (limits basements) | 21.2% |
| Septic fields very limited | 76.5% |
| Clay swell (LEP, by area) | 1.7% |
| High-swell land (LEP 6%+) | under 0.1% |
| Urban land, not rated | 2.2% |
| Mapped soil | 289,500 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Glenelg | 24% | 0% |
| Brinklow | 22% | n/a |
| Penn | 8% | n/a |
| Manor | 7% | n/a |
| Glenville | 6% | n/a |
| Gaila | 3% | n/a |
How we count · survey areas MD013 (2025-09-09)
What the numbers mean here
On 21% of Carroll 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: 34.23 in, 11.31 in below the 1991-2020 average year of 45.54 in.
USDA rates 77% of the land very limited for septic absorption fields.
Drought
66.6% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 51 of the last 52 weeks; the most was 100% of its area, in 33 weeks, most recently on the August 11, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 66.6% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
27 flood losses since 2016, $324,376 paid. The worst year was 2018, with 11.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 0 |
| 2018 | 11 |
| 2019 | 1 |
| 2020 | 4 |
| 2021 | 6 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 4 |
| 2025 | 1 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 45.54 in |
| 12 months to August 2026 | 34.23 in (-11.31) |
| 2025 | 36.82 in (-8.72) |
| Wettest year since 1895 | 2018: 69.81 in |
| Driest year since 1895 | 1930: 24.95 in |
| Days with 1 inch or more, normal at HANOVER 4 SW (14 mi away) | 11.4 |
Homes
| Housing units | 66,768 |
| Median year built | 1983 |
| Built before 1980 | 44% |
| Built 2000 or later | 21% |
| Owner-occupied | 84% |
| Median value, owner-occupied | $434,000 |
| Single-family detached | 78% |
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 |
|---|---|---|---|
| Frederick County, MD | 21 mi | 1% | 22% |
| Howard County, MD | 22 mi | 1% | 24% |
| Baltimore County, MD | 23 mi | 2% | 23% |
| Adams County, PA | 24 mi | under 1% | 45% |
| Baltimore city, MD | 28 mi | 5% | 18% |
| York County, PA | 29 mi | under 1% | 20% |
| Montgomery County, MD | 31 mi | 1% | 19% |
| Harford County, MD | 38 mi | 5% | 29% |
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