Sullivan County, New York
A shallow water table limits basements on 52% of Sullivan County's mapped land, a higher share than 68% of US counties. Shrink-swell clay limits houses without basements on under 1%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 39 flood losses here since 2016, 60% of them in buildings with basements. 57% of homes were built before 1980, against 50% nationally; the median home dates from 1974.
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 Sullivan County
| Expansive clay (limits slab homes) | 0.1% |
| High water table (limits basements) | 51.8% |
| Septic fields very limited | 83.0% |
| Clay swell (LEP, by area) | 1.3% |
| High-swell land (LEP 6%+) | 0.1% |
| Mapped soil | 637,800 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Wellsboro | 16% | n/a |
| Wurtsboro | 9% | n/a |
| Arnot | 8% | n/a |
| Oquaga | 6% | n/a |
| Willowemoc | 5% | n/a |
| Lackawanna | 4% | n/a |
How we count · survey areas NY105 (2025-08-27)
What the numbers mean here
On 52% of Sullivan 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: 43.13 in, 6.43 in below the 1991-2020 average year of 49.56 in.
USDA rates 83% 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 19 of the last 52 weeks; the most was 26.1% of its area, in 7 weeks, most recently on the March 10, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 0% |
| D1 moderate drought or worse | 0% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
39 flood losses since 2016, $399,708 paid. The worst year was 2017, with 13. Foundations of the buildings, where recorded: 60% basements, 20% slabs, 16% crawl spaces, 4% elevated. Median water depth outside the building: 16 in.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 13 |
| 2018 | 5 |
| 2019 | 0 |
| 2020 | 3 |
| 2021 | 10 |
| 2022 | 2 |
| 2023 | 0 |
| 2024 | 0 |
| 2025 | 0 |
| 2026 to date | 6 |
Rain
| Average year, 1991-2020 | 49.56 in |
| 12 months to August 2026 | 43.13 in (-6.43) |
| 2025 | 43.88 in (-5.68) |
| Wettest year since 1895 | 2011: 74.12 in |
| Driest year since 1895 | 1964: 32.68 in |
| Days with 1 inch or more, normal at PORT JERVIS (23 mi away) | 10.9 |
Homes
| Housing units | 49,994 |
| Median year built | 1974 |
| Built before 1980 | 57% |
| Built 2000 or later | 18% |
| Owner-occupied | 67% |
| Median value, owner-occupied | $249,000 |
| Single-family detached | 70% |
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 |
|---|---|---|---|
| Wayne County, PA | 27 mi | 0% | 64% |
| Pike County, PA | 30 mi | 0% | 64% |
| Ulster County, NY | 30 mi | 2% | 36% |
| Orange County, NY | 33 mi | 0% | 54% |
| Delaware County, NY | 34 mi | 0% | 49% |
| Sussex County, NJ | 41 mi | 0% | 16% |
| Lackawanna County, PA | 47 mi | 0% | 53% |
| Greene County, NY | 51 mi | 1% | 35% |
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