Denver County, Colorado
USDA's soil survey flags shrink-swell clay on 15% of Denver County's mapped land and a shallow water table under basements on 3%, both below the national shares of 15% and 29%. 100% of the county is in drought on the October 13, 2026 Drought Monitor map.
FEMA's flood data list 42 flood losses here since 2016, 88% of them in buildings with basements. 56% of homes were built before 1980, against 50% nationally; the median home dates from 1975.
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 Denver County
| Expansive clay (limits slab homes) | 14.8% |
| High water table (limits basements) | 2.7% |
| Septic fields very limited | 45.2% |
| Clay swell (LEP, by area) | 4.3% |
| High-swell land (LEP 6%+) | 20.1% |
| Urban land, not rated | 31.8% |
| Mapped soil | 99,215 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Elyria | 8% | n/a |
| Ascalon | 6% | n/a |
| Truckton | 6% | n/a |
| Platner | 5% | n/a |
| Racas | 3% | n/a |
| Weld | 3% | n/a |
How we count · survey areas CO001 (2025-08-29), CO031 (2025-08-29), CO641 (2025-08-29)
What the numbers mean here
Rain over the 12 months to August 2026: 10.07 in, 5.00 in below the 1991-2020 average year of 15.07 in.
With shrink-swell clay on 15% and a shallow water table on 3% of the land, the soil survey points to neither problem across most of Denver 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 41 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 | 100% |
| D3 extreme or worse | 0.2% |
| D4 exceptional | 0% |
Flood losses since 2016
42 flood losses since 2016, $76,206 paid. The worst year was 2023, with 12. Foundations of the buildings, where recorded: 88% basements, 8% slabs, 4% crawl spaces.
| Year | Flood losses |
|---|---|
| 2016 | 1 |
| 2017 | 5 |
| 2018 | 4 |
| 2019 | 6 |
| 2020 | 0 |
| 2021 | 4 |
| 2022 | 4 |
| 2023 | 12 |
| 2024 | 3 |
| 2025 | 2 |
| 2026 to date | 1 |
Rain
| Average year, 1991-2020 | 15.07 in |
| 12 months to August 2026 | 10.07 in (-5.00) |
| 2025 | 13.03 in (-2.04) |
| Wettest year since 1895 | 1923: 23.00 in |
| Driest year since 1895 | 1954: 7.56 in |
| Days with 1 inch or more, normal at DENVER-STAPLETON (1 mi away) | 2.2 |
Homes
| Housing units | 359,581 |
| Median year built | 1975 |
| Built before 1980 | 56% |
| Built 2000 or later | 31% |
| Owner-occupied | 49% |
| Median value, owner-occupied | $616,000 |
| Single-family detached | 41% |
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 |
|---|---|---|---|
| Broomfield County, CO | 16 mi | 46% | 1% |
| Jefferson County, CO | 23 mi | 17% | 2% |
| Adams County, CO | 30 mi | 11% | 2% |
| Douglas County, CO | 30 mi | 3% | 2% |
| Arapahoe County, CO | 30 mi | 22% | 1% |
| Gilpin County, CO | 35 mi | 0% | 3% |
| Boulder County, CO | 36 mi | 9% | 6% |
| Clear Creek County, CO | 42 mi | 0% | 3% |
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