Larimer County, Colorado
USDA's soil survey flags shrink-swell clay on 6% of Larimer County's mapped land and a shallow water table under basements on 4%, 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 23 flood losses here since 2016. 32% of homes were built before 1980, against 50% nationally; the median home dates from 1993.
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 Larimer County
| Expansive clay (limits slab homes) | 5.7% |
| High water table (limits basements) | 4.0% |
| Septic fields very limited | 71.4% |
| Clay swell (LEP, by area) | 2.2% |
| High-swell land (LEP 6%+) | 5.9% |
| Mapped soil | 1,683,200 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Boyle | 5% | n/a |
| Redfeather | 4% | n/a |
| Wetmore | 3% | n/a |
| Catamount family | 2% | n/a |
| Nunn | 2% | n/a |
| Satanta | 2% | n/a |
How we count · survey areas CO642 (2025-08-29), CO644 (2025-08-29), CO645 (2025-08-29), CO651 (2025-08-29)
What the numbers mean here
Rain over the 12 months to August 2026: 15.76 in, 4.72 in below the 1991-2020 average year of 20.48 in.
USDA rates 71% of the land very limited for septic absorption fields.
With shrink-swell clay on 6% and a shallow water table on 4% of the land, the soil survey points to neither problem across most of Larimer 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 46 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 | 64.8% |
| D4 exceptional | 25.9% |
Flood losses since 2016
23 flood losses since 2016, $370,040 paid. The worst year was 2023, with 6.
| Year | Flood losses |
|---|---|
| 2016 | 1 |
| 2017 | 0 |
| 2018 | 4 |
| 2019 | 2 |
| 2020 | 0 |
| 2021 | 4 |
| 2022 | 4 |
| 2023 | 6 |
| 2024 | 0 |
| 2025 | 1 |
| 2026 to date | 1 |
Rain
| Average year, 1991-2020 | 20.48 in |
| 12 months to August 2026 | 15.76 in (-4.72) |
| 2025 | 18.30 in (-2.18) |
| Wettest year since 1895 | 1923: 29.97 in |
| Driest year since 1895 | 1939: 12.01 in |
| Days with 1 inch or more, normal at HOURGLASS RSVR (9 mi away) | 1.1 |
Homes
| Housing units | 164,690 |
| Median year built | 1993 |
| Built before 1980 | 32% |
| Built 2000 or later | 39% |
| Owner-occupied | 64% |
| Median value, owner-occupied | $569,100 |
| Single-family detached | 64% |
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 |
|---|---|---|---|
| Boulder County, CO | 39 mi | 9% | 6% |
| Jackson County, CO | 44 mi | 18% | 16% |
| Grand County, CO | 50 mi | 5% | 6% |
| Broomfield County, CO | 54 mi | 46% | 1% |
| Gilpin County, CO | 55 mi | 0% | 3% |
| Weld County, CO | 58 mi | 7% | 2% |
| Laramie County, WY | 62 mi | 1% | 2% |
| Clear Creek County, CO | 68 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