Adams County, Pennsylvania

A shallow water table limits basements on 45% of Adams County's mapped land, a higher share than 63% of US counties. Shrink-swell clay limits houses without basements on under 1%.

12.3% of the county is in drought on the October 13, 2026 Drought Monitor map, down from 22.9% a week earlier. FEMA's flood data list 41 flood losses here since 2016, 48% of them in buildings with basements. 50% of homes were built before 1980, against 50% nationally; the median home dates from 1980.

Data as of October 13, 2026 · sources

<1%

expansive clay: shrink-swell limits slab homes

45%

high water table: limits basements

12%

in drought, October 13, 2026

50%

of homes built before 1980

Soil under Adams County

Expansive clay (limits slab homes)	0.1%
High water table (limits basements)	45.5%
Septic fields very limited	85.4%
Clay swell (LEP, by area)	2.0%
High-swell land (LEP 6%+)	0.5%
Mapped soil	333,894 acres

Soil series	Share here	Series nationally: high water table
Penn	10%	n/a
Highfield	9%	n/a
Abbottstown	7%	n/a
Lehigh	6%	n/a
Croton	6%	n/a
Edgemont	5%	n/a

Adams County (heavy outline) and nearby counties, shaded by high water table share.under 10%10-25%25-40%40-60%60%+

How we count · survey areas PA001 (2025-09-04)

What the numbers mean here

On 45% of Adams 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: 35.34 in, 9.58 in below the 1991-2020 average year of 44.92 in.

USDA rates 85% of the land very limited for septic absorption fields.

Drought

12.3% 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 30 weeks, most recently on the July 7, 2026 map.

October 21, 2025Share of area in drought, weeklyOctober 13, 2026

Category, October 13, 2026	Share of county
D0 abnormally dry or worse	31%
D1 moderate drought or worse	12.3%
D2 severe or worse	0%
D3 extreme or worse	0%
D4 exceptional	0%

Flood losses since 2016

41 flood losses since 2016, $726,924 paid. The worst year was 2021, with 23. Foundations of the buildings, where recorded: 48% basements, 13% slabs, 16% crawl spaces, 23% elevated. Median water depth outside the building: 13.5 in.

Year	Flood losses
2016	0
2017	0
2018	7
2019	3
2020	1
2021	23
2022	1
2023	0
2024	5
2025	0
2026 to date	1

Rain

Average year, 1991-2020	44.92 in
12 months to August 2026	35.34 in (-9.58)
2025	37.62 in (-7.30)
Wettest year since 1895	2018: 68.48 in
Driest year since 1895	1930: 24.65 in
Days with 1 inch or more, normal at BIGLERVILLE (5 mi away)	11.9

Homes

Housing units	43,672
Median year built	1980
Built before 1980	50%
Built 2000 or later	22%
Owner-occupied	79%
Median value, owner-occupied	$268,500
Single-family detached	75%

What repairs cost

Published ranges from cost guides, not quotes. More sources, and where they disagree.

Work	Range	Source
Basement waterproofing, US	$3,000 to $10,000	Fixr, February 6, 2026
Sump pump installation, US	$800 to $2,000	Fixr, January 31, 2025
Crawl space encapsulation, US	$2,000 to $8,000	Fixr, August 29, 2025

Nearby counties

Place	Distance	Expansive clay	High water table
Cumberland County, PA	21 mi	1%	23%
Carroll County, MD	24 mi	0%	21%
York County, PA	26 mi	under 1%	20%
Franklin County, PA	27 mi	4%	32%
Frederick County, MD	29 mi	1%	22%
Perry County, PA	37 mi	under 1%	29%
Washington County, MD	37 mi	9%	18%
Dauphin County, PA	43 mi	under 1%	21%

Sources: USDA SSURGO (September 4, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status