Soil series profile
Webster soil series
Webster is a poorly drained soil with a clay loam surface, mapped on 1,768,779 acres in 63 counties across 2 states. Hydrologic group C/D.
- Drainage class
- Poorly drained 100% of mapped acres
- Hydrologic group
- C/D 98% of mapped acres
- Typical topsoil pH
- 6.5 slightly acidic · range 6.5–6.5
- Mapped area
- 1.8M acres in 63 counties, 2 states
Typical Webster profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–10 in (Ap) | Clay loam | 6.5 | 33% | 25% | 7% |
| 10–20 in (A) | Clay loam | 6.9 | 33% | 25% | 5% |
| 20–42 in (Bg) | Clay loam | 7.3 | 28% | 35% | 1.5% |
| 42–79 in (Cg) | Loam | 8.0 | 21% | 44% | 0.25% |
What this means
What Webster soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Webster soils is slightly acidic: pH 6.5, the range most vegetables, flowers and lawn grasses prefer.
Loamy topsoil (loam, silt loam and similar) covers 100% of mapped Webster acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is clay loam (98% of mapped Webster acres).
100% of mapped Webster acres is somewhat poorly to very poorly drained, so soil stays soggy for long spells after rain and in wet seasons. Raised beds, plants that tolerate wet feet, and not working the soil while wet all help.
For lawns and yards
On 100% 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.
A seasonal high water table comes within 18 inches of the surface on 100% of mapped acres, often in spring. Basements, sump pumps and lawns in low spots feel it first.
For a septic system
For conventional septic absorption fields, NRCS rates 100% of the acres in mapped Webster soils very limited, 0% somewhat limited and 0% not limited.
Where the soil is very limited (slow permeability, a high water table, flooding, shallow bedrock or steep slopes), alternative systems such as mound or sand-filter designs are common and cost more.
Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.
Where Webster soil is found
Mapped acres
Webster is mapped in Iowa and Minnesota. The 60 counties with the most Webster acres:
| County | Acres | Share of county land |
|---|---|---|
| Pocahontas County, IA | 89,902 | 24.4% |
| Calhoun County, IA | 89,143 | 24.4% |
| Webster County, IA | 80,527 | 17.7% |
| Brown County, MN | 68,695 | 17.6% |
| Story County, IA | 64,331 | 17.6% |
| Freeborn County, MN | 64,105 | 14.2% |
| Cottonwood County, MN | 55,762 | 13.6% |
| Steele County, MN | 55,526 | 20.2% |
| Redwood County, MN | 55,356 | 9.8% |
| Kossuth County, IA | 55,354 | 8.9% |
| Nobles County, MN | 54,003 | 11.8% |
| Greene County, IA | 53,344 | 14.6% |
| Hancock County, IA | 43,348 | 11.9% |
| Renville County, MN | 41,068 | 6.5% |
| Wright County, IA | 40,071 | 10.8% |
| Martin County, MN | 37,374 | 8.2% |
| Palo Alto County, IA | 36,728 | 10.2% |
| Humboldt County, IA | 36,689 | 13.2% |
| Hardin County, IA | 34,228 | 9.4% |
| Boone County, IA | 33,666 | 9.2% |
| Sibley County, MN | 33,663 | 8.9% |
| Buena Vista County, IA | 32,659 | 8.9% |
| Polk County, IA | 32,255 | 8.8% |
| Watonwan County, MN | 31,126 | 11.2% |
| Franklin County, IA | 30,520 | 8.2% |
| Yellow Medicine County, MN | 30,368 | 6.3% |
| Dallas County, IA | 29,861 | 8.0% |
| Murray County, MN | 27,887 | 6.2% |
| Cerro Gordo County, IA | 27,796 | 7.7% |
| Faribault County, MN | 27,351 | 6.0% |
| Jackson County, MN | 26,973 | 6.0% |
| Hamilton County, IA | 26,191 | 7.1% |
| Waseca County, MN | 25,990 | 9.6% |
| Winnebago County, IA | 23,031 | 9.0% |
| Sac County, IA | 21,882 | 5.9% |
| Scott County, MN | 21,850 | 9.7% |
| Emmet County, IA | 21,599 | 8.6% |
| Dickinson County, IA | 20,611 | 8.5% |
| Blue Earth County, MN | 19,084 | 4.0% |
| Nicollet County, MN | 19,061 | 6.6% |
| Guthrie County, IA | 17,729 | 4.7% |
| Carroll County, IA | 17,248 | 4.7% |
| Worth County, IA | 17,124 | 6.7% |
| Lac qui Parle County, MN | 16,703 | 3.4% |
| Clay County, IA | 13,888 | 3.8% |
| Osceola County, IA | 10,956 | 4.3% |
| McLeod County, MN | 9,493 | 3.0% |
| Meeker County, MN | 8,543 | 2.2% |
| Carver County, MN | 7,403 | 3.2% |
| Kandiyohi County, MN | 6,767 | 1.3% |
| Lyon County, MN | 5,779 | 1.3% |
| Marshall County, IA | 3,279 | 0.9% |
| Le Sueur County, MN | 3,189 | 1.1% |
| Dakota County, MN | 2,312 | 0.6% |
| Chippewa County, MN | 2,296 | 0.6% |
| Rice County, MN | 1,989 | 0.6% |
| Wright County, MN | 1,306 | 0.3% |
| Anoka County, MN | 1,290 | 0.5% |
| Jasper County, IA | 987 | 0.2% |
| Hennepin County, MN | 681 | 0.2% |
Septic absorption fields
NRCS rating, share of Webster acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 0.0% |
| Very limited | 100.0% |
Drainage, water table and flooding
Share of Webster acres
- Depth to seasonal high water table
- About 0 inches (median where reported); within 18 inches on 100% of acres.
- Flooding
- Not mapped as flooding on most acres.
- Slope
- Typically 1–1% (median 1%).
- Topsoil organic matter
- Median 7%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 0.0% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 100.0% |
| Very poorly drained | 0.0% |
Hydrologic soil group
Show as a table
| Category | Share of acres |
|---|---|
| A: fast infiltration (mostly sandy or gravelly) | 0.0% |
| B: moderate infiltration | 0.0% |
| C: slow infiltration | 0.0% |
| 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 | 1.8% |
| C/D: D as is, C if drained | 98.2% |
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 Webster (component kind "Series") in SSURGO: 1,768,779 acres.
- Method
- Shares are by mapped acres of Webster components. The profile comes from the single largest Webster component. Full methodology.