Soil series profile
Santiago soil series
Santiago is a well drained soil with a silt loam surface, mapped on 160,054 acres in 17 counties across 2 states. Hydrologic group C.
- Drainage class
- Well drained 100% of mapped acres
- Hydrologic group
- C 56% of mapped acres
- Typical topsoil pH
- 5.9 moderately acidic · range 5.9–5.9
- Mapped area
- 160k acres in 17 counties, 2 states
Typical Santiago profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–7 in (Ap) | Silt loam | 5.9 | 10% | 33% | 3% |
| 7–11 in (A2) | Silt loam | 5.5 | 10% | 33% | 0.25% |
| 11–20 in (A&B,B&A) | Silt loam | 5.5 | 23% | 22% | 0.25% |
| 20–34 in (2B21-22t,2B3) | Loam | 5.5 | 22% | 41% | 0.25% |
| 34–60 in (2C) | Sandy loam | 6.2 | 9% | 68% | 0.25% |
What this means
What Santiago soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Santiago soils is moderately acidic: pH 5.9. Many vegetables grow well here, and some gardens benefit from a little lime. Test before adding any.
Loamy topsoil (loam, silt loam and similar) covers 100% of mapped Santiago acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silt loam (100% of mapped Santiago acres).
100% of mapped Santiago acres is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
On 56% 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 67% of the acres in mapped Santiago soils very limited, 33% 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 Santiago soil is found
Mapped acres
Santiago is mapped in Wisconsin and Minnesota.
| County | Acres | Share of county land |
|---|---|---|
| Polk County, WI | 45,657 | 7.8% |
| St. Croix County, WI | 44,689 | 9.7% |
| Barron County, WI | 19,070 | 3.5% |
| Chippewa County, WI | 14,403 | 2.2% |
| Washington County, MN | 13,948 | 5.6% |
| Dunn County, WI | 5,348 | 1.0% |
| Pierce County, WI | 4,969 | 1.4% |
| Sawyer County, WI | 3,272 | 0.4% |
| Rusk County, WI | 2,848 | 0.5% |
| Wood County, WI | 1,684 | 0.3% |
| Marathon County, WI | 1,140 | 0.1% |
| Lincoln County, WI | 1,000 | 0.2% |
| Price County, WI | 852 | 0.1% |
| Ramsey County, MN | 582 | 0.6% |
| Taylor County, WI | 452 | 0.1% |
| Langlade County, WI | 83 | 0.0% |
| Eau Claire County, WI | 55 | 0.0% |
Septic absorption fields
NRCS rating, share of Santiago acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 33.0% |
| Very limited | 67.0% |
Drainage, water table and flooding
Share of Santiago 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 4–9% (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 | 100.0% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 0.0% |
| 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 | 43.8% |
| C: slow infiltration | 56.1% |
| 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% |
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 Santiago (component kind "Series") in SSURGO: 160,054 acres.
- Method
- Shares are by mapped acres of Santiago components. The profile comes from the single largest Santiago component. Full methodology.