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Delphos, Ohio
Inside Delphos' city limits, a shallow water table limits basements on 95% of mapped land, higher than 84% of Ohio cities. Shrink-swell clay limits houses without basements on 80%, the highest of 9 cities in Allen County.
That water-table share is close to Allen County's 93%. FEMA's flood data list 16 flood losses since 2016 in ZIP code 45833 overlapping the city. Of its 3,296 homes, 76% were built before 1980; the median dates from 1958.
Data as of October 13, 2026 · sources · in Allen County
expansive clay: shrink-swell limits slab homes
high water table: limits basements
flood losses since 2016 in 1 overlapping ZIP
of homes built before 1980
Basement waterproofing in Delphos
Basement waterproofing in Delphos: a shallow water table limits basements on 95% of Delphos' mapped land, more than in 84% of Ohio cities, and the ZIP code overlapping Delphos logged 16 FEMA flood losses since 2016.
In Allen County, 14% of the 37 flood-loss buildings with a recorded foundation type had basements.
About 2,500 of Delphos' 3,296 homes are detached houses.
Soil under Delphos city limits
| Expansive clay (limits slab homes) | 79.8% |
| High water table (limits basements) | 94.6% |
| Septic fields very limited | 94.6% |
| Clay swell (LEP, by area) | 5.1% |
| High-swell land (LEP 6%+) | 5.6% |
| Urban land, not rated | 1.9% |
| Mapped soil | 2,152 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Hoytville | 67% | 99% |
| Nappanee | 15% | n/a |
| Wabasha | 4% | n/a |
| Houcktown | 3% | n/a |
| St. Clair | 2% | n/a |
| Aurand | 1% | n/a |
What the numbers mean here
Clay swell averages a linear extensibility of 5.1% by land area here, and 6% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 80% of the mapped land.
On 95% of Delphos' mapped land, soil stays saturated within about 6 feet of the surface for part of the year, which is basement depth.
USDA rates 95% of the land very limited for septic absorption fields.
Drought in Allen County
0% of Allen County is in drought (D1 or worse) on the October 13, 2026 map. County detail.
Flood losses by ZIP code
FEMA flood records since 2016 in the ZIP codes that overlap Delphos. ZIP areas reach past city limits.
| ZIP | Share of city land | Flood losses | Paid |
|---|---|---|---|
| 45833 | 100% | 16 | $259,919 |
Homes in Delphos
| Housing units | 3,296 |
| Median year built | 1958 |
| Built before 1980 | 76% |
| Built 2000 or later | 6% |
| Owner-occupied | 72% |
| Median value, owner-occupied | $129,600 |
| Single-family detached | 76% |
Nearby cities
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Fort Jennings | 5 mi | 71% | 96% |
| Middle Point | 6 mi | 74% | 97% |
| Ottoville | 6 mi | 57% | 83% |
| Venedocia | 8 mi | 29% | 100% |
| Elida | 8 mi | 17% | 74% |
| Spencerville | 10 mi | 29% | 99% |
| Elgin | 10 mi | 69% | over 99% |
| Cloverdale | 12 mi | 93% | 98% |
Sources: USDA SSURGO (August 5, 2026) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · Census ACS 2020-2024. Methods · Data status