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Dukes County, Massachusetts

A shallow water table limits basements on 17% of Dukes County's mapped land. Shrink-swell clay limits houses without basements on 0%.

None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 13 flood losses here since 2016. 45% of homes were built before 1980, against 50% nationally; the median home dates from 1982.

Data as of October 13, 2026 · sources

0%

expansive clay: shrink-swell limits slab homes

17%

high water table: limits basements

0%

in drought, October 13, 2026

45%

of homes built before 1980

Soil under Dukes County

Expansive clay (limits slab homes)0.0%
High water table (limits basements)17.0%
Septic fields very limited72.9%
Clay swell (LEP, by area)0.8%
High-swell land (LEP 6%+)0.0%
Mapped soil79,245 acres
Soil seriesShare hereSeries nationally: high water table
Carver23%n/a
Eastchop13%n/a
Riverhead7%n/a
Plymouth4%n/a
Haven3%n/a
Deerfield3%n/a
Newport County: 66%Nantucket County: 16%Bristol County: 63%Barnstable County: 19%Bristol County: 38%Plymouth County: 51%Washington County: 38%Kent County: 34%Dukes County NewportNantucketBristolBarnstableBristolPlymouthWashingtonKentDukes
Dukes 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 MA007 (2025-09-05)

What the numbers mean here

On 17% of Dukes 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: 35.08 in, 12.05 in below the 1991-2020 average year of 47.13 in.

USDA rates 73% 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 37 of the last 52 weeks; the most was 100% of its area, in 22 weeks, most recently on the September 22, 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 worse0%
D2 severe or worse0%
D3 extreme or worse0%
D4 exceptional0%

Flood losses since 2016

13 flood losses since 2016, $161,347 paid. The worst year was 2018, with 7.

YearFlood losses
20160
20170
20187
20190
20200
20210
20220
20231
20245
20250
2026 to date0

Rain

Average year, 1991-202047.13 in
12 months to August 202635.08 in (-12.05)
202540.14 in (-6.99)
Wettest year since 18951972: 65.15 in
Driest year since 18951965: 27.05 in
Days with 1 inch or more, normal at EDGARTOWN (10 mi away)12.9

Homes

Housing units17,822
Median year built1982
Built before 198045%
Built 2000 or later17%
Owner-occupied82%
Median value, owner-occupied$1.2 million
Single-family detached91%

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
Newport County, RI 31 mi 0% 66%
Nantucket County, MA 32 mi 0% 16%
Bristol County, MA 32 mi 0% 63%
Barnstable County, MA 36 mi 0% 19%
Bristol County, RI 38 mi 0% 38%
Plymouth County, MA 42 mi 0% 51%
Washington County, RI 48 mi 0% 38%
Kent County, RI 50 mi 0% 34%

Sources: USDA SSURGO (September 5, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status