HomeSouth CarolinaUnion County

Union County, South Carolina

A shallow water table limits basements on 17% of Union County's mapped land. Shrink-swell clay limits houses without basements on 8%.

None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list no flood losses here since 2016. 64% of homes were built before 1980, against 50% nationally; the median home dates from 1972.

Data as of October 13, 2026 · sources

8%

expansive clay: shrink-swell limits slab homes

17%

high water table: limits basements

0%

in drought, October 13, 2026

64%

of homes built before 1980

Soil under Union County

Expansive clay (limits slab homes)7.8%
High water table (limits basements)17.5%
Septic fields very limited62.7%
Clay swell (LEP, by area)2.8%
High-swell land (LEP 6%+)7.9%
Mapped soil330,500 acres
Soil seriesShare hereSeries nationally: high water table
Madison28%0%
Wilkes19%n/a
Cecil9%0%
Cataula7%n/a
Pacolet7%0%
Enon7%n/a
Cherokee County: 5%Chester County: 19%Laurens County: 19%Spartanburg County: 10%Newberry County: 28%York County: 23%Fairfield County: 15%Cleveland County: 7%Union County CherokeeChesterLaurensSpartanburgNewberryYorkFairfieldClevelandUnion
Union 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 SC087 (2025-08-29)

What the numbers mean here

On 17% of Union 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: 34.14 in, 11.14 in below the 1991-2020 average year of 45.28 in.

USDA rates 63% of the land very limited for septic absorption fields.

Drought

0% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 43 of the last 52 weeks; the most was 100% of its area, in 31 weeks, most recently on the July 28, 2026 map.

October 21, 2025Share of area in drought, weeklyOctober 13, 2026
Category, October 13, 2026Share of county
D0 abnormally dry or worse0%
D1 moderate drought or worse0%
D2 severe or worse0%
D3 extreme or worse0%
D4 exceptional0%

Flood losses since 2016

FEMA's flood data list no flood losses in Union County since 2016.

Rain

Average year, 1991-202045.28 in
12 months to August 202634.14 in (-11.14)
202539.21 in (-6.07)
Wettest year since 18951929: 74.07 in
Driest year since 18952007: 28.33 in
Days with 1 inch or more, normal at UNION 8 S (6 mi away)13.2

Homes

Housing units13,527
Median year built1972
Built before 198064%
Built 2000 or later13%
Owner-occupied71%
Median value, owner-occupied$103,600
Single-family detached69%

What repairs cost

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

WorkRangeSource
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

PlaceDistanceExpansive clayHigh water table
Cherokee County, SC 25 mi 1% 5%
Chester County, SC 26 mi 7% 19%
Laurens County, SC 26 mi 7% 19%
Spartanburg County, SC 27 mi 1% 10%
Newberry County, SC 28 mi 13% 28%
York County, SC 31 mi 23% 23%
Fairfield County, SC 34 mi 1% 15%
Cleveland County, NC 45 mi 1% 7%

Sources: USDA SSURGO (August 29, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status