Sussex County, Delaware
A shallow water table limits basements on 61% of Sussex County's mapped land, a higher share than 75% of US counties and the 2nd highest of 3 Delaware counties. Shrink-swell clay limits houses without basements on 0%.
8.2% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 321 flood losses here since 2016, 7% of them in buildings with basements. 24% of homes were built before 1980, against 50% nationally; the median home dates from 1999.
Data as of October 13, 2026 · sources
expansive clay: shrink-swell limits slab homes
high water table: limits basements
in drought, October 13, 2026
of homes built before 1980
Soil under Sussex County
| Expansive clay (limits slab homes) | 0.0% |
| High water table (limits basements) | 60.9% |
| Septic fields very limited | 72.2% |
| Clay swell (LEP, by area) | 1.2% |
| High-swell land (LEP 6%+) | 0.0% |
| Mapped soil | 592,381 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Rosedale | 8% | n/a |
| Hurlock | 7% | n/a |
| Pepperbox | 5% | n/a |
| Mullica | 5% | n/a |
| Hammonton | 5% | n/a |
| Fort Mott | 4% | n/a |
How we count · survey areas DE005 (2025-09-09)
What the numbers mean here
On 61% of Sussex 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: 36.57 in, 9.65 in below the 1991-2020 average year of 46.22 in.
USDA rates 72% of the land very limited for septic absorption fields.
Drought
8.2% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 46 of the last 52 weeks; the most was 100% of its area, in 15 weeks, most recently on the August 4, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 23% |
| D1 moderate drought or worse | 8.2% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
321 flood losses since 2016, $2.7 million paid. The worst year was 2016, with 141. Foundations of the buildings, where recorded: 7% basements, 12% slabs, 41% crawl spaces, 40% elevated. Median water depth outside the building: 9 in.
| Year | Flood losses |
|---|---|
| 2016 | 141 |
| 2017 | 10 |
| 2018 | 22 |
| 2019 | 20 |
| 2020 | 17 |
| 2021 | 44 |
| 2022 | 11 |
| 2023 | 22 |
| 2024 | 11 |
| 2025 | 18 |
| 2026 to date | 5 |
Rain
| Average year, 1991-2020 | 46.22 in |
| 12 months to August 2026 | 36.57 in (-9.65) |
| 2025 | 42.17 in (-4.05) |
| Wettest year since 1895 | 1948: 65.47 in |
| Driest year since 1895 | 1930: 26.43 in |
| Days with 1 inch or more, normal at SALISBURY WICOMICO RGNL AP (25 mi away) | 12.4 |
Homes
| Housing units | 151,799 |
| Median year built | 1999 |
| Built before 1980 | 24% |
| Built 2000 or later | 49% |
| Owner-occupied | 82% |
| Median value, owner-occupied | $382,600 |
| Single-family detached | 65% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Wicomico County, MD | 27 mi | under 1% | 84% |
| Caroline County, MD | 30 mi | 0% | 86% |
| Kent County, DE | 31 mi | 0% | 77% |
| Worcester County, MD | 31 mi | 0% | 86% |
| Cape May County, NJ | 39 mi | 0% | 67% |
| Dorchester County, MD | 42 mi | 0% | 69% |
| Talbot County, MD | 46 mi | 0% | 65% |
| Cumberland County, NJ | 47 mi | 0% | 50% |
Sources: USDA SSURGO (September 9, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status