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Ottawa, Ohio
Inside Ottawa's city limits, a shallow water table limits basements on 84% of mapped land, higher than 69% of Ohio cities. Shrink-swell clay limits houses without basements on 62%.
That water-table share is below Putnam County's 96%. FEMA's flood data list 7 flood losses since 2016 in ZIP code 45875 overlapping the city. Of its 1,920 homes, 65% were built before 1980; the median dates from 1974.
Data as of October 13, 2026 · sources · in Putnam 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 Ottawa
Basement waterproofing in Ottawa: a shallow water table limits basements on 84% of Ottawa's mapped land, more than in 69% of Ohio cities, and the ZIP code overlapping Ottawa logged 7 FEMA flood losses since 2016.
About 1,400 of Ottawa's 1,920 homes are detached houses.
Soil under Ottawa city limits
| Expansive clay (limits slab homes) | 62.2% |
| High water table (limits basements) | 83.5% |
| Septic fields very limited | 83.5% |
| Clay swell (LEP, by area) | 6.7% |
| High-swell land (LEP 6%+) | 66.0% |
| Urban land, not rated | 10.0% |
| Mapped soil | 2,950 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Fulton | 26% | n/a |
| Toledo | 25% | n/a |
| Paulding | 7% | 98% |
| Del Rey | 4% | n/a |
| Haskins | 3% | n/a |
| Genesee | 3% | n/a |
What the numbers mean here
Clay swell averages a linear extensibility of 6.7% by land area here, and 66% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 62% of the mapped land.
On 84% of Ottawa's mapped land, soil stays saturated within about 6 feet of the surface for part of the year, which is basement depth.
USDA rates 84% of the land very limited for septic absorption fields.
Drought in Putnam County
0% of Putnam 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 Ottawa. ZIP areas reach past city limits.
| ZIP | Share of city land | Flood losses | Paid |
|---|---|---|---|
| 45875 | 100% | 7 | $39,448 |
Homes in Ottawa
| Housing units | 1,920 |
| Median year built | 1974 |
| Built before 1980 | 65% |
| Built 2000 or later | 13% |
| Owner-occupied | 75% |
| Median value, owner-occupied | $190,700 |
| Single-family detached | 72% |
Nearby cities
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Glandorf | 2 mi | 45% | 93% |
| Gilboa | 6 mi | 51% | 94% |
| West Leipsic | 6 mi | 40% | 76% |
| Pandora | 7 mi | 13% | 91% |
| Columbus Grove | 7 mi | 49% | 83% |
| Leipsic | 7 mi | 77% | 93% |
| Miller City | 8 mi | 94% | 95% |
| Kalida | 8 mi | 39% | 90% |
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