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Oliver County, North Dakota

USDA's soil survey flags shrink-swell clay on 13% of Oliver County's mapped land and a shallow water table under basements on 5%, both below the national shares of 15% and 29%. 100% 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. 62% of homes were built before 1980, against 50% nationally; the median home dates from 1976.

Data as of October 13, 2026 · sources

13%

expansive clay: shrink-swell limits slab homes

5%

high water table: limits basements

100%

in drought, October 13, 2026

62%

of homes built before 1980

Soil under Oliver County

Expansive clay (limits slab homes)12.7%
High water table (limits basements)4.8%
Septic fields very limited78.7%
Clay swell (LEP, by area)3.9%
High-swell land (LEP 6%+)14.2%
Mapped soil467,900 acres
Soil seriesShare hereSeries nationally: expansive clay
Williams14%0%
Werner6%n/a
Arnegard5%n/a
Amor5%n/a
Vebar5%n/a
Zahl4%n/a
Mercer County: 15%Morton County: 32%McLean County: 9%Burleigh County: 12%Grant County: 23%Sheridan County: 15%Dunn County: 22%Stark County: 37%Oliver County MercerMortonMcLeanBurleighGrantSheridanDunnStarkOliver
Oliver County (heavy outline) and nearby counties, shaded by expansive clay share.under 10%10-25%25-40%40-60%60%+

How we count · survey areas ND065 (2026-05-04)

What the numbers mean here

Rain over the 12 months to August 2026: 15.10 in, 2.76 in below the 1991-2020 average year of 17.86 in.

USDA rates 79% of the land very limited for septic absorption fields.

With shrink-swell clay on 13% and a shallow water table on 5% of the land, the soil survey points to neither problem across most of Oliver County; conditions still vary lot by lot.

Drought

100% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 11 of the last 52 weeks; the most was 100% of its area, in 11 weeks, most recently on the October 13, 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 worse100%
D2 severe or worse100%
D3 extreme or worse0%
D4 exceptional0%

Flood losses since 2016

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

Rain

Average year, 1991-202017.86 in
12 months to August 202615.10 in (-2.76)
202520.43 in (+2.57)
Wettest year since 18951993: 24.58 in
Driest year since 18951936: 6.54 in
Days with 1 inch or more, normal at NEW SALEM 5NW (17 mi away)3

Homes

Housing units893
Median year built1976
Built before 198062%
Built 2000 or later16%
Owner-occupied95%
Median value, owner-occupied$215,700
Single-family detached83%

What repairs cost

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

WorkRangeSource
Foundation repair, US $2,200 to $8,200 Fixr, January 27, 2026
Pier-and-beam repair, US $2,000 to $15,000 Fixr, January 27, 2026
Foundation inspection, US $300 to $600 Fixr, January 31, 2025

Nearby counties

PlaceDistanceExpansive clayHigh water table
Mercer County, ND 26 mi 15% 4%
Morton County, ND 28 mi 32% 5%
McLean County, ND 37 mi 9% 13%
Burleigh County, ND 42 mi 12% 11%
Grant County, ND 54 mi 23% 5%
Sheridan County, ND 57 mi 15% 31%
Dunn County, ND 62 mi 22% 5%
Stark County, ND 66 mi 37% 4%

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