Soil series profile

Weld soil series

Weld is a well drained soil with a silt loam surface, mapped on 790,857 acres in 18 counties across 2 states. Hydrologic group C.

#276 by mapped area fine Aridic Argiustolls (Mollisols)

Drainage class: Well drained
Hydrologic group: C
Typical topsoil pH: 7.0
Mapped area: 791k

Typical Weld profile

Texture and pH by depth

Depth to scale. More strongly shaded layers hold more clay. Horizon names are the soil survey's (A = topsoil, B = subsoil, C = parent material).

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Typical Weld horizons (representative values)
Depth	Texture	pH	Clay	Sand	Organic matter
0–3 in (Ap)	Silt loam	7.0	19%	27%	2%
3–11 in (Bt1)	Silty clay	7.4	42%	8%	1.6%
11–15 in (Bt2)	Silty clay	7.6	42%	8%	1%
15–21 in (Btk)	Silty clay	8.3	42%	8%	0.5%
21–31 in (Bk)	Silt loam	8.5	22%	26%	0.25%
31–80 in (C)	Silt loam	8.5	19%	27%	0.1%

Representative values from the most extensive Weld map unit (Weld silt loam, 0 to 3 percent slopes, survey area CO121). Other map units of this series vary within the series range.

Stock photo for illustration, not a sample of this soil series. Credit on the Sources & method page.

What this means

What Weld soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Weld soils is neutral: pH 7.0 (most land between 7.0 and 7.2), the range most vegetables, flowers and lawn grasses prefer.

Loamy topsoil (loam, silt loam and similar) covers >99% of mapped Weld acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silt loam (61% of mapped Weld acres).

>99% of mapped Weld acres is moderately well to excessively drained, which suits most garden plants.

For lawns and yards

On >99% of mapped acres, rain soaks in slowly (hydrologic groups C and D, including dual groups that are D until drained). Expect runoff and puddles after heavy rain: core-aerate compacted lawns and keep ground sloping away from foundations.

For a septic system

For conventional septic absorption fields, NRCS rates 10% of the acres in mapped Weld soils very limited, 88% somewhat limited and 2% not limited.

Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.

Generated from the mapped numbers above using fixed rules, not a site visit. See how these notes are written.

Where Weld soil is found

Mapped acres

Weld is mapped in Colorado and Wyoming.

Counties with the most mapped Weld soil
County	Acres	Share of county land
Washington County, CO	234,194	14.5%
Lincoln County, CO	115,626	7.0%
Adams County, CO	98,368	12.9%
Kit Carson County, CO	81,634	5.9%
Elbert County, CO	72,771	6.2%
Weld County, CO	65,103	2.5%
Arapahoe County, CO	33,890	6.5%
Logan County, CO	26,766	2.3%
Morgan County, CO	24,450	3.0%
Cheyenne County, CO	11,157	1.0%
Bent County, CO	6,750	0.7%
Larimer County, CO	6,174	0.4%
Boulder County, CO	5,607	1.2%
Goshen County, WY	3,438	0.2%
Denver County, CO	2,380	2.3%
Phillips County, CO	1,355	0.3%
Jefferson County, CO	55	0.0%
Broomfield County, CO	8	0.0%

Septic absorption fields

NRCS rating, share of Weld acres

Not limited 2%

Somewhat limited 88%

Very limited 10%

Not rated <1%

Septic tank absorption field rating across mapped Weld acres. Scale 0 to 100% of mapped land.

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Septic tank absorption field rating across mapped Weld acres.
Category	Share of acres
Not limited	1.5%
Somewhat limited	88.3%
Very limited	10.1%
Not rated	0.1%

Drainage, water table and flooding

Share of Weld acres

Depth to seasonal high water table: None reported within about 6.5 feet (median where reported).
Flooding: Not mapped as flooding on most acres.
Slope: Typically 1–2% (median 1%).
Topsoil organic matter: Median 2%.

Drainage class

Excessively drained 0%

Somewhat excessively drained 0%

Well drained >99%

Moderately well drained 0%

Somewhat poorly drained 0%

Poorly drained 0%

Very poorly drained 0%

Not rated <1%

Drainage class across mapped Weld acres. Scale 0 to 100% of mapped land.

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Drainage class across mapped Weld acres.
Category	Share of acres
Excessively drained	0.0%
Somewhat excessively drained	0.0%
Well drained	99.9%
Moderately well drained	0.0%
Somewhat poorly drained	0.0%
Poorly drained	0.0%
Very poorly drained	0.0%
Not rated	0.1%

Hydrologic soil group

A: fast infiltration (mostly sandy or gravelly) 0%

B: moderate infiltration <1%

C: slow infiltration >99%

D: very slow infiltration (clayey, shallow or wet) 0%

A/D: D as is, A if drained 0%

B/D: D as is, B if drained 0%

C/D: D as is, C if drained 0%

Not rated <1%

Hydrologic soil group across mapped Weld acres. Scale 0 to 100% of mapped land.

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Hydrologic soil group across mapped Weld acres.
Category	Share of acres
A: fast infiltration (mostly sandy or gravelly)	0.0%
B: moderate infiltration	0.4%
C: slow infiltration	99.5%
D: very slow infiltration (clayey, shallow or wet)	0.0%
A/D: D as is, A if drained	0.0%
B/D: D as is, B if drained	0.0%
C/D: D as is, C if drained	0.0%
Not rated	0.1%

Sources & data dates

Source: USDA NRCS Soil Survey Geographic Database (SSURGO), queried through Soil Data Access. Public domain.
Data date: SSURGO as published on November 3, 2026 (most recent survey area update October 26, 2026). NRCS refreshes SSURGO each October.
Scope: All map unit components named Weld (component kind "Series") in SSURGO: 790,857 acres.
Method: Shares are by mapped acres of Weld components. The profile comes from the single largest Weld component. Full methodology.

Independent reference site. No government affiliation or endorsement.

Full narrative description: USDA Official Soil Series Description for Weld.