HomeSouth CarolinaAllendale County

Allendale County, South Carolina

A shallow water table limits basements on 80% of Allendale County's mapped land, a higher share than 88% of US counties. Shrink-swell clay limits houses without basements on 0%.

51.1% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 3 flood losses here since 2016. 55% of homes were built before 1980, against 50% nationally; the median home dates from 1977.

Data as of October 13, 2026 · sources

0%

expansive clay: shrink-swell limits slab homes

80%

high water table: limits basements

51%

in drought, October 13, 2026

55%

of homes built before 1980

Soil under Allendale County

Expansive clay (limits slab homes)0.0%
High water table (limits basements)79.7%
Septic fields very limited75.5%
Clay swell (LEP, by area)1.8%
High-swell land (LEP 6%+)0.0%
Mapped soil379,658 acres
Soil seriesShare hereSeries nationally: high water table
Blanton14%n/a
Bonneau9%n/a
Uchee6%n/a
Norfolk6%63%
Rains5%n/a
Emporia5%n/a
Hampton County: 99%Barnwell County: 65%Screven County: 70%Bamberg County: 85%Jenkins County: 65%Burke County: 53%Colleton County: 92%Aiken County: 32%Allendale County HamptonBarnwellScrevenBambergJenkinsBurkeColletonAikenAllendale
Allendale 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 SC005 (2025-09-02), SC696 (2025-08-29)

What the numbers mean here

On 80% of Allendale 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: 29.12 in, 17.96 in below the 1991-2020 average year of 47.08 in.

USDA rates 76% of the land very limited for septic absorption fields.

Drought

51.1% 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 27 weeks, most recently on the June 9, 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 worse51.1%
D2 severe or worse0%
D3 extreme or worse0%
D4 exceptional0%

Flood losses since 2016

3 flood losses since 2016, $277,668 paid. The worst year was 2025, with 1.

YearFlood losses
20160
20170
20180
20190
20200
20210
20220
20231
20241
20251
2026 to date0

Rain

Average year, 1991-202047.08 in
12 months to August 202629.12 in (-17.96)
202541.15 in (-5.93)
Wettest year since 18951948: 66.79 in
Driest year since 18951931: 27.94 in
Days with 1 inch or more, normal at ALLENDALE 2 NW (4 mi away)14

Homes

Housing units4,050
Median year built1977
Built before 198055%
Built 2000 or later12%
Owner-occupied62%
Median value, owner-occupied$76,200
Single-family detached66%

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
Hampton County, SC 19 mi 0% 99%
Barnwell County, SC 20 mi 0% 65%
Screven County, GA 22 mi 0% 70%
Bamberg County, SC 24 mi 2% 85%
Jenkins County, GA 37 mi 9% 65%
Burke County, GA 37 mi under 1% 53%
Colleton County, SC 42 mi 5% 92%
Aiken County, SC 42 mi under 1% 32%

Sources: USDA SSURGO (September 2, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status