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Buying land in Jefferson County, Colorado: what to check

Jefferson County covers 764 square miles of land and 10 of water in Colorado, with about 578,533 residents in 2024 (down 0.8% since 2020). The 2020 Census counted 78% of its land as rural and 93% of residents as living in urban areas. Farms operate 8.9% of the county's land. Below: how much of Jefferson County floods, what its soils allow, what farmland is worth and how often it's in drought, from free public data with every source linked.

Check a location in Jefferson CountySee a sample report

Jefferson County at a glance

In the 100-year floodplain

14%

Above the state's county median (under 1%)

FEMA National Risk Index

Hydric (wetland-type) soils

1.7%

About the state's county median (1.7%)

USDA NRCS Web Soil Survey (SSURGO)

Soils very limited for septic

95%

USDA NRCS Web Soil Survey (SSURGO)

Farm land value, 2022

$16,602/acre

Above the state's county median ($2,779)

USDA NASS, 2022 Census of Agriculture

Weeks in severe drought

22%

Share of weekly maps, 2021–2026

U.S. Drought Monitor county statistics

Land classed rural

78%

Census 2020 Census urban and rural classification

What to check before buying land in Jefferson County

Ordered by what Jefferson County's numbers point to. Every parcel differs, so treat this as where to look first.

  1. 1.Budget for a perc test and maybe an engineered septic

    USDA rates 95% of Jefferson County's mapped soils "very limited" for conventional septic absorption fields and under 1% "not limited".

    Without city sewer you need a septic permit from the county or state health department. Make the offer contingent on a passing soil or perc test; mound and aerobic systems can cost several times a conventional one.

    Guide: Perc tests and septic systems

  2. 2.Check slope where you'd build and where the driveway goes

    66% of Jefferson County's mapped soils have an average slope over 15% (USDA SSURGO).

    Steep ground means grading, retaining walls, longer driveways and erosion control. Compare the slope at the house site and along the access route, not just the parcel average.

    Guide: Terrain and slope

  3. 3.Put flood checks first in Jefferson County

    14% of the county's area is in the 1%-annual-chance (100-year) floodplain FEMA's National Risk Index uses for inland flooding; 1.8% of its mapped soils flood occasionally or frequently. FEMA rates Jefferson County's river-flooding risk relatively high.

    Look up the FEMA flood zone at the pin, not the parcel's address. If any of the land is in zone A or V, price flood insurance before you offer, ask for an elevation certificate, and check whether the access road floods too.

    Guide: Flood zones before buying land

  4. 4.Check wildfire exposure and insurance

    FEMA rates Jefferson County's wildfire risk relatively high, and 4.3% of the county's area is in the wildfire exposure zone the National Risk Index uses.

    Ask an insurer for a quote early; some carriers won't write new policies in high-hazard areas. Check access for fire trucks, nearby fire stations and the vegetation around the building site.

    Guide: Wildfire risk for rural land

  5. 5.Find out where the water comes from

    At least half of Jefferson County was in severe drought (D2) or worse in 22% of the 262 weekly U.S. Drought Monitor maps from 2021 to 2026. Colorado allocates water by permit or water right, so a well or pond isn't automatic.

    Ask whether the land has a public water connection, an existing well (and its log and yield), or neighbors' well depths from the state well database. For a new well, check permits and typical depth with the state agency first.

    Guide: Wells, public water and water rights

  6. 6.Sanity-check the price per acre

    Farm real estate in Jefferson County averaged $16,602 an acre including buildings in the 2022 Census of Agriculture, and 2.8% of its mapped soils are prime or of statewide importance.

    Compare the asking price with recent sales of similar tracts, not the county average, which mixes cropland, pasture, timber and homesites. If an ag tax valuation applies, ask what the rollback taxes would be if you change the use.

    Guide: Land due diligence checklist

Flood zones, wetlands and water in Jefferson County

Area in the 1%-annual-chance (100-year) floodplain
14%, 3rd highest of 64 in Colorado FEMA National Risk Index
Mapped soils that flood occasionally or frequently
1.8% USDA NRCS Web Soil Survey (SSURGO)
Hydric soils (a federal wetland indicator)
1.7% USDA NRCS Web Soil Survey (SSURGO)
Poorly or very poorly drained soils
1.2% USDA NRCS Web Soil Survey (SSURGO)
Surface water (lakes, rivers, reservoirs)
10 sq mi Census 2024 Gazetteer Files
Drought on 2026-10-27
100% moderate or worse, 100% severe or worse U.S. Drought Monitor county statistics

The floodplain share is the area FEMA's National Risk Index counts as exposed to inland flooding, mostly mapped 100-year flood zones. It says how common flood-prone land is in Jefferson County, not whether a given parcel floods. For that, look up the zone at your exact point on the FEMA Flood Map Service Center or run the free check.

Soils and terrain

Prime farmland
0% USDA NRCS Web Soil Survey (SSURGO)
Prime only if drained, irrigated or protected
5% USDA NRCS Web Soil Survey (SSURGO)
Farmland of statewide importance
2.8% USDA NRCS Web Soil Survey (SSURGO)
Average slope over 15%
66% USDA NRCS Web Soil Survey (SSURGO)
Very limited for septic absorption fields
95% USDA NRCS Web Soil Survey (SSURGO)
Not limited for septic absorption fields
under 1% USDA NRCS Web Soil Survey (SSURGO)

Shares of Jefferson County's soil-surveyed land (about 516,060 acres, open water excluded), using each map unit's dominant condition in USDA's SSURGO soil survey. Soils change within a few hundred feet, so the soil at your building site is what matters.

Farms and land use

Farms (2022)
531 USDA NASS, 2022 Census of Agriculture
Share of the county's land in farms
8.9% USDA NASS, 2022 Census of Agriculture
Average farm size
82 acres (median 13) USDA NASS, 2022 Census of Agriculture
Average value of land and buildings
$16,602 per acre, 3rd highest of 63 in Colorado USDA NASS, 2022 Census of Agriculture
Cropland
7,813 acres USDA NASS, 2022 Census of Agriculture
Pasture and rangeland
26,689 acres USDA NASS, 2022 Census of Agriculture
Woodland on farms
15,113 acres USDA NASS, 2022 Census of Agriculture
Irrigated land
987 acres USDA NASS, 2022 Census of Agriculture

Natural hazard ratings

FEMA's National Risk Index rates each hazard for Jefferson County relative to every other U.S. county. Overall risk: Relatively High.

  • HailVery High
  • LightningVery High
  • Winter weatherVery High
  • River and inland floodingRelatively High
  • Strong windRelatively High
  • TornadoRelatively High
  • WildfireRelatively High
  • LandslideRelatively Moderate
  • EarthquakeRelatively Low
  • Heat waveRelatively Low
  • DroughtVery Low

FEMA National Risk Index, December 2025

Questions about buying land in Jefferson County

How much of Jefferson County, CO is in a flood zone?

About 14% of Jefferson County's area is in the 1%-annual-chance (100-year) floodplain used by FEMA's National Risk Index (December 2025), 3rd highest of 64 counties in Colorado. Whether a given parcel is in a flood zone depends on its exact location, so check the FEMA map at your pin.

How much does land cost per acre in Jefferson County?

The 2022 Census of Agriculture put the average value of farm land and buildings in Jefferson County at $16,602 an acre, 3rd highest of 63 counties in Colorado (the median Colorado county was $2,779). It's a self-reported average across farms, so small homesites and recreational tracts often sell for more per acre.

Will a septic system work on land in Jefferson County?

Often, but test first. USDA soil surveys rate 95% of Jefferson County's mapped soils very limited for conventional septic absorption fields, usually because of wetness, slow permeability, shallow rock or flooding. A perc or soil test on the parcel decides what system the health department will permit.

Is there good farmland in Jefferson County?

0% of Jefferson County's mapped soils are prime farmland, 5% are prime only if drained, irrigated or protected from flooding, and 2.8% are farmland of statewide importance (USDA SSURGO). The 2022 Census of Agriculture counted 531 farms averaging 82 acres.

How often is Jefferson County in drought?

Since 2021, at least half of the county was in severe drought or worse in 22% of weekly U.S. Drought Monitor maps, and in extreme drought in 5.7%. On 2026-10-27, 100% of the county was in moderate drought or worse.

Can I check a specific property in Jefferson County?

Yes. Enter the address or drop a pin anywhere in Jefferson County on the free check. It shows which checks return data at that exact point, and the full report costs $29: flood zone, slope, soils, wetlands, roads, power lines, wildfire and more, each with its source. It is a screen of public maps, not a survey, title search or perc test.

Check the parcel, not just the county

County numbers tell you what to look for. The free check looks at your exact point in Jefferson County: flood zone, slope, soils, wetlands, roads, power and more. The full report is $29.

Check a location in Jefferson County

What these numbers can't tell you

  • County shares describe Jefferson County as a whole; a parcel can be entirely in or out of a flood zone, wetland or poor soil.
  • It doesn't look at the whole parcel, its boundaries, title, easements, zoning or permits.
  • It isn't a survey, appraisal, elevation certificate, soil or perc test, or Phase I environmental site assessment.
  • It can't see local distribution power lines, driveways, legal access, wells or mineral rights.
  • Maps lag behind the ground, and distances are straight-line, not driving distance.

Sources and vintages

Summarized per county by our build script on 2026-10-31. County figures cover the whole county; checks on the report are at your point.