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Union County, North Carolina

A shallow water table limits basements on 28% of Union County's mapped land. Shrink-swell clay limits houses without basements on 3%.

96.1% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 40 flood losses here since 2016, 4% of them in buildings with basements. 20% of homes were built before 1980, against 50% nationally; the median home dates from 2000.

Data as of October 13, 2026 · sources

3%

expansive clay: shrink-swell limits slab homes

28%

high water table: limits basements

96%

in drought, October 13, 2026

20%

of homes built before 1980

Soil under Union County

Expansive clay (limits slab homes)2.9%
High water table (limits basements)27.9%
Septic fields very limited71.4%
Clay swell (LEP, by area)3.4%
High-swell land (LEP 6%+)2.7%
Mapped soil409,139 acres
Soil seriesShare hereSeries nationally: high water table
Badin30%n/a
Tarrus19%n/a
Cid18%n/a
Goldston11%n/a
Chewacla5%n/a
Cecil4%0%
Lancaster County: 21%Anson County: 37%Mecklenburg County: 16%Stanly County: 18%Cabarrus County: 22%Chesterfield County: 43%York County: 23%Chester County: 19%Union County LancasterAnsonMecklenburgStanlyCabarrusChesterfieldYorkChesterUnion
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 NC179 (2025-08-27)

What the numbers mean here

On 28% 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: 30.43 in, 13.13 in below the 1991-2020 average year of 43.56 in.

USDA rates 71% of the land very limited for septic absorption fields.

Drought

96.1% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 52 of the last 52 weeks; the most was 100% of its area, in 41 weeks, most recently on the September 29, 2026 map.

October 21, 2025Share of area in drought, weeklyOctober 13, 2026
Category, October 13, 2026Share of county
D0 abnormally dry or worse100%
D1 moderate drought or worse96.1%
D2 severe or worse0%
D3 extreme or worse0%
D4 exceptional0%

Flood losses since 2016

40 flood losses since 2016, $1.2 million paid. The worst year was 2018, with 18. Foundations of the buildings, where recorded: 4% basements, 25% slabs, 42% crawl spaces, 29% elevated. Median water depth outside the building: 10 in.

YearFlood losses
20163
20172
201818
20190
20206
20211
20220
20233
20244
20250
2026 to date3

Rain

Average year, 1991-202043.56 in
12 months to August 202630.43 in (-13.13)
202533.32 in (-10.24)
Wettest year since 18951929: 62.20 in
Driest year since 18952007: 27.63 in
Days with 1 inch or more, normal at MONROE 2 SE (1 mi away)13.8

Homes

Housing units88,851
Median year built2000
Built before 198020%
Built 2000 or later49%
Owner-occupied82%
Median value, owner-occupied$417,300
Single-family detached86%

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
Lancaster County, SC 23 mi 2% 21%
Anson County, NC 24 mi 15% 37%
Mecklenburg County, NC 25 mi 16% 16%
Stanly County, NC 27 mi 4% 18%
Cabarrus County, NC 28 mi 22% 22%
Chesterfield County, SC 32 mi 0% 43%
York County, SC 37 mi 23% 23%
Chester County, SC 41 mi 7% 19%

Sources: USDA SSURGO (August 27, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status