Soil series profile
Miami soil series
Miami is a moderately well drained soil with a silt loam surface, mapped on 821,169 acres in 79 counties across 5 states. Hydrologic group C.
- Drainage class
- Moderately well drained 78% of mapped acres
- Hydrologic group
- C 81% of mapped acres
- Typical topsoil pH
- 6.5 slightly acidic · range 5.9–7.0
- Mapped area
- 821k acres in 79 counties, 5 states
Typical Miami profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–10 in (Ap) | Silt loam | 6.5 | 24% | 22% | 1.25% |
| 10–30 in (Bt) | Clay loam | 5.6 | 31% | 35% | 0.25% |
| 30–60 in (C) | Loam | 7.9 | 21% | 42% | 0.1% |
What this means
What Miami soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Miami soils is slightly acidic: pH 6.5 (most land between 5.9 and 7.0), the range most vegetables, flowers and lawn grasses prefer.
Loamy topsoil (loam, silt loam and similar) covers >99% of mapped Miami acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silt loam (60% of mapped Miami acres).
>99% of mapped Miami acres is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
On 84% 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 95% of the acres in mapped Miami soils very limited, 5% 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 Miami soil is found
Mapped acres
Miami is mapped in Indiana, Wisconsin, Michigan, Ohio and Illinois. The 60 counties with the most Miami acres:
| County | Acres | Share of county land |
|---|---|---|
| Walworth County, WI | 56,457 | 15.9% |
| Dodge County, WI | 49,917 | 8.9% |
| Champaign County, OH | 45,127 | 16.5% |
| Hamilton County, IN | 34,906 | 13.9% |
| Hendricks County, IN | 34,793 | 13.4% |
| Johnson County, IN | 34,511 | 17.0% |
| Marion County, IN | 31,986 | 12.9% |
| Clinton County, IN | 29,316 | 11.4% |
| Wayne County, IN | 28,500 | 11.3% |
| Livingston County, MI | 27,177 | 7.5% |
| Shelby County, IN | 26,624 | 10.2% |
| Decatur County, IN | 26,549 | 11.2% |
| Hancock County, IN | 26,220 | 13.4% |
| Boone County, IN | 23,221 | 8.6% |
| Morgan County, IN | 22,432 | 8.8% |
| Noble County, IN | 21,730 | 8.3% |
| Wabash County, IN | 20,762 | 7.9% |
| Putnam County, IN | 20,546 | 6.7% |
| Madison County, IN | 18,876 | 6.6% |
| Franklin County, IN | 18,531 | 7.5% |
| Ionia County, MI | 18,043 | 4.9% |
| Montgomery County, IN | 16,386 | 5.1% |
| Kosciusko County, IN | 13,884 | 4.1% |
| Bartholomew County, IN | 13,699 | 5.3% |
| Rush County, IN | 11,994 | 4.6% |
| Cass County, IN | 11,583 | 4.4% |
| Steuben County, IN | 11,349 | 5.8% |
| Howard County, IN | 10,759 | 5.8% |
| Tippecanoe County, IN | 10,621 | 3.4% |
| Waukesha County, WI | 9,532 | 2.7% |
| McLean County, IL | 7,135 | 0.9% |
| Carroll County, IN | 4,924 | 2.1% |
| Warren County, IN | 4,885 | 2.2% |
| Genesee County, MI | 4,807 | 1.2% |
| Shiawassee County, MI | 4,791 | 1.4% |
| Clinton County, MI | 4,671 | 1.3% |
| Kenosha County, WI | 4,550 | 2.6% |
| Delaware County, IN | 4,381 | 1.7% |
| Washtenaw County, MI | 3,829 | 0.8% |
| Racine County, WI | 3,799 | 1.8% |
| Whitley County, IN | 3,587 | 1.7% |
| Preble County, OH | 3,532 | 1.3% |
| Lenawee County, MI | 3,493 | 0.7% |
| Ingham County, MI | 3,385 | 1.0% |
| Benton County, IN | 3,324 | 1.3% |
| Fountain County, IN | 3,303 | 1.3% |
| De Witt County, IL | 2,970 | 1.2% |
| St. Joseph County, IN | 2,510 | 0.9% |
| Green County, WI | 2,169 | 0.6% |
| Eaton County, MI | 2,146 | 0.6% |
| Miami County, IN | 2,137 | 0.9% |
| Fayette County, IN | 1,912 | 1.4% |
| Elkhart County, IN | 1,885 | 0.6% |
| Vermillion County, IN | 1,851 | 1.2% |
| Jennings County, IN | 1,724 | 0.7% |
| Pulaski County, IN | 1,615 | 0.6% |
| Tazewell County, IL | 1,076 | 0.3% |
| Ottawa County, MI | 815 | 0.2% |
| Allen County, IN | 735 | 0.2% |
| Fulton County, IN | 670 | 0.3% |
Septic absorption fields
NRCS rating, share of Miami acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 5.2% |
| Very limited | 94.6% |
| Not rated | 0.2% |
Drainage, water table and flooding
Share of Miami acres
- Depth to seasonal high water table
- About 2.5 feet (30 in) (median where reported).
- Flooding
- Not mapped as flooding on most acres.
- Slope
- Typically 4–15% (median 4%).
- Topsoil organic matter
- Median 2%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 21.9% |
| Moderately well drained | 78.0% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 0.0% |
| Very poorly drained | 0.0% |
| Not rated | 0.1% |
Hydrologic soil group
Show as a table
| Category | Share of acres |
|---|---|
| A: fast infiltration (mostly sandy or gravelly) | 0.0% |
| B: moderate infiltration | 15.7% |
| C: slow infiltration | 81.3% |
| D: very slow infiltration (clayey, shallow or wet) | 0.3% |
| 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 | 2.6% |
| Not rated | 0.2% |
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 Miami (component kind "Series") in SSURGO: 821,169 acres.
- Method
- Shares are by mapped acres of Miami components. The profile comes from the single largest Miami component. Full methodology.