County soil summary

Soil types in Brown County, Wisconsin

The most widespread soils are Kewaunee, Manawa and Oshkosh; the most common drainage class is well drained (54% of the land), and typical topsoil pH is 6.7.

Mapped soil survey data 299,000 acres of mapped land · 61 named soil series

Well or moderately well drained
61%
of land · state 65%
Typical topsoil pH
6.7
neutral · state 5.9
Septic fields very limited
89%
of land · state 92%
Subject to flooding
9%
of land, any frequency · state 7%

Most common soils in Brown County

Share of mapped land

A county is a patchwork of many soils. These 8 cover 68% of the mapped land; 61 named soil series are mapped here in all.

Most common soils in Brown County by share of mapped land
Soil Share of land Drainage Topsoil pH
Kewaunee 26.8% Well drained 6.5
Manawa 12.9% Somewhat poorly drained 7.0
Oshkosh 11.1% Well drained 7.0
Waymor 6.2% Well drained 7.0
Poygan 3.4% Poorly drained 7.1
Shawano 3.1% Excessively drained 5.9
Tedrow 2.8% Somewhat poorly drained 6.7
Solona 2.0% Somewhat poorly drained 7.2

Drainage and pH for a series are its typical values across all its mapped acres nationwide. A dash means the row is not a soil series.

What this means

What the soils in Brown County mean for gardens, lawns and septic systems

For your garden

Typical topsoil in Brown County is neutral: pH 6.7 (most land between 6.5 and 7.1), the range most vegetables, flowers and lawn grasses prefer.

Loamy topsoil (loam, silt loam and similar) covers 79% of the land: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silt loam (52% of the land).

61% of the land is moderately well to excessively drained, which suits most garden plants.

For your lawn and yard

On 84% of the land, 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 33% of the land, 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 89% of the land in Brown County very limited, 4% somewhat limited and 0% not limited (8% not rated, such as urban land, pits or water).

That is close to the state as a whole (92% very 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.

Flooding is mapped on 9% of the land (2% occasional, 6% frequent).

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.

Drainage

How long the soil stays wet

The most common drainage class is well drained (54%). 61% of the land is moderately well drained or better, compared with 65% across Wisconsin.

Excessively drained 3%
Somewhat excessively drained <1%
Well drained 54%
Moderately well drained 3%
Somewhat poorly drained 24%
Poorly drained 8%
Very poorly drained 4%
Not rated 5%
Natural drainage class, share of mapped land in Brown County. Scale 0 to 100% of mapped land.
Show as a table
Natural drainage class, share of mapped land in Brown County.
CategoryBrown CountyWisconsin
Excessively drained3.1%8.5%
Somewhat excessively drained0.6%5.1%
Well drained54.1%36.1%
Moderately well drained2.7%15.1%
Somewhat poorly drained23.7%14.3%
Poorly drained7.5%7.4%
Very poorly drained3.5%11.3%
Not rated4.8%2.2%

Septic absorption fields

NRCS rating for conventional drain fields

The rating looks at the soil from 24 to 60 inches deep: permeability, depth to a seasonal water table or bedrock, flooding and slope. “Very limited” means at least one feature is unfavorable enough that a conventional field is hard to make work.

Not limited 0%
Somewhat limited 4%
Very limited 89%
Not rated 8%
Septic tank absorption field rating, share of mapped land in Brown County. Scale 0 to 100% of mapped land.
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Septic tank absorption field rating, share of mapped land in Brown County.
CategoryBrown CountyWisconsin
Not limited0.0%0.0%
Somewhat limited3.7%4.9%
Very limited88.5%91.9%
Not rated7.8%3.2%

Rain, runoff and water table

Hydrologic soil group, flooding, seasonal water table

Hydrologic soil group

How fast rain soaks in when the soil is already wet. Group A soaks in fastest, D slowest.

A: fast infiltration (mostly sandy or gravelly) 5%
B: moderate infiltration 4%
C: slow infiltration 22%
D: very slow infiltration (clayey, shallow or wet) 32%
A/D: D as is, A if drained 5%
B/D: D as is, B if drained 8%
C/D: D as is, C if drained 17%
Not rated 8%
Hydrologic soil group, share of mapped land in Brown County. Scale 0 to 100% of mapped land.
Show as a table
Hydrologic soil group, share of mapped land in Brown County.
CategoryBrown CountyWisconsin
A: fast infiltration (mostly sandy or gravelly)4.6%19.7%
B: moderate infiltration4.1%19.8%
C: slow infiltration21.5%16.5%
D: very slow infiltration (clayey, shallow or wet)32.1%6.2%
A/D: D as is, A if drained5.3%10.7%
B/D: D as is, B if drained7.8%10.3%
C/D: D as is, C if drained16.9%13.3%
Not rated7.8%3.5%

Flooding

No flooding 86%
Rare or very rare 1%
Occasional 2%
Frequent or very frequent 6%
Not reported 5%
Most frequent flooding class in any month, share of mapped land in Brown County. Scale 0 to 100% of mapped land.
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Most frequent flooding class in any month, share of mapped land in Brown County.
CategoryBrown CountyWisconsin
No flooding86.1%91.3%
Rare or very rare1.0%0.4%
Occasional1.7%2.4%
Frequent or very frequent6.3%3.7%
Not reported4.9%2.2%

Seasonal high water table

Within 18 inches at some time of year 33%
18 inches to 3.3 feet 4%
Deeper than 3.3 feet or none reported 58%
Not reported 5%
Shallowest depth to a saturated zone in any month, share of mapped land in Brown County. Scale 0 to 100% of mapped land.
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Shallowest depth to a saturated zone in any month, share of mapped land in Brown County.
CategoryBrown CountyWisconsin
Within 18 inches at some time of year33.1%36.9%
18 inches to 3.3 feet4.2%8.0%
Deeper than 3.3 feet or none reported57.9%53.1%
Not reported4.8%2.0%

Topsoil pH and texture

First mineral layer of each soil

Typical topsoil pH is 6.7 (neutral); 80% of rated land falls between 6.5 and 7.1. Median topsoil organic matter is 2%.

Strongly acidic (below 5.5) 0%
Moderately to slightly acidic (5.5–6.4) 6%
Near neutral (6.5–7.3) 82%
Alkaline (7.4 and up) 2%
Not reported 11%
Topsoil pH band, share of mapped land in Brown County. Scale 0 to 100% of mapped land.
Show as a table
Topsoil pH band, share of mapped land in Brown County.
CategoryBrown CountyWisconsin
Strongly acidic (below 5.5)0.0%18.5%
Moderately to slightly acidic (5.5–6.4)5.6%43.9%
Near neutral (6.5–7.3)82.4%26.0%
Alkaline (7.4 and up)1.5%0.5%
Not reported10.5%11.1%

Texture

Sandy 9%
Loamy (loam, silt loam and similar) 79%
Clayey (40%+ clay) <1%
Organic (muck or peat) 4%
Not reported (rock, urban land, etc.) 8%
Topsoil texture group, share of mapped land in Brown County. Scale 0 to 100% of mapped land.
Show as a table
Topsoil texture group, share of mapped land in Brown County.
CategoryBrown CountyWisconsin
Sandy8.8%17.8%
Loamy (loam, silt loam and similar)78.7%66.3%
Clayey (40%+ clay)0.5%0.5%
Organic (muck or peat)4.1%12.1%
Not reported (rock, urban land, etc.)7.8%3.4%

Most common surface textures: silt loam 52% · silty clay loam 16% · loamy fine sand 8% · fine sandy loam 6% · loam 5%.

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
Brown County, Wisconsin (FIPS 55009): 299,199 acres of mapped land, 49,851 acres of open water excluded. State comparisons pool all mapped land in Wisconsin.
Method
Shares are by mapped land area: each map unit’s acres in the county times each soil component’s percentage. Open water is excluded. Topsoil values use the first mineral horizon of each component. Full methodology.

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