Delta County, Colorado
USDA's soil survey flags shrink-swell clay on 12% of Delta County's mapped land and a shallow water table under basements on 3%, both below the national shares of 15% and 29%. The soil survey maps 74% of the county's land area; these shares describe the mapped part.
100% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 1 flood losses here since 2016. 51% of homes were built before 1980, against 50% nationally; the median home dates from 1979.
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 Delta County
| Expansive clay (limits slab homes) | 11.7% |
| High water table (limits basements) | 3.1% |
| Septic fields very limited | 83.6% |
| Clay swell (LEP, by area) | 3.7% |
| High-swell land (LEP 6%+) | 12.3% |
| Mapped soil | 538,638 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Agua Fria | 9% | n/a |
| Delson | 7% | n/a |
| Utaline | 5% | n/a |
| Mesa | 4% | n/a |
| Saraton | 4% | n/a |
| Kech | 4% | n/a |
How we count · survey areas CO677 (2025-08-29), CO679 (2025-08-29)
What the numbers mean here
Rain over the 12 months to August 2026: 13.31 in, 4.19 in below the 1991-2020 average year of 17.50 in.
USDA rates 84% of the land very limited for septic absorption fields.
With shrink-swell clay on 12% and a shallow water table on 3% of the land, the soil survey points to neither problem across most of Delta County; conditions still vary lot by lot.
Drought
100% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 52 of the last 52 weeks; the most was 100% of its area, in 52 weeks, most recently on the October 13, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 100% |
| D2 severe or worse | 80.4% |
| D3 extreme or worse | 11.2% |
| D4 exceptional | 0% |
Flood losses since 2016
1 flood losses since 2016, $0 paid. The worst year was 2017, with 1.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 1 |
| 2018 | 0 |
| 2019 | 0 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 0 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 17.50 in |
| 12 months to August 2026 | 13.31 in (-4.19) |
| 2025 | 11.81 in (-5.69) |
| Wettest year since 1895 | 1957: 27.21 in |
| Driest year since 1895 | 2020: 9.98 in |
| Days with 1 inch or more, normal at PAONIA 1SW (13 mi away) | 0.5 |
Homes
| Housing units | 15,025 |
| Median year built | 1979 |
| Built before 1980 | 51% |
| Built 2000 or later | 25% |
| Owner-occupied | 78% |
| Median value, owner-occupied | $343,200 |
| Single-family detached | 78% |
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 |
|---|---|---|---|
| Mesa County, CO | 33 mi | 13% | 1% |
| Montrose County, CO | 38 mi | 22% | 5% |
| Gunnison County, CO | 45 mi | 9% | 6% |
| Ouray County, CO | 49 mi | 19% | 6% |
| Garfield County, CO | 51 mi | 5% | 1% |
| Pitkin County, CO | 57 mi | n/a | n/a |
| San Miguel County, CO | 66 mi | 3% | 1% |
| Hinsdale County, CO | 74 mi | under 1% | 2% |
Sources: USDA SSURGO (August 29, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status