Soil series profile
Riverhead soil series
Riverhead is a well drained soil with a sandy loam surface, mapped on 208,485 acres in 34 counties across 4 states. Hydrologic group A.
- Drainage class
- Well drained >99% of mapped acres
- Hydrologic group
- A 89% of mapped acres
- Typical topsoil pH
- 5.0 very strongly acidic · range 4.8–5.2
- Mapped area
- 208k acres in 34 counties, 4 states
Typical Riverhead profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–12 in (H1) | Sandy loam | 5.2 | 10% | 69% | 3% |
| 12–27 in (H2) | Sandy loam | 5.2 | 10% | 67% | 1% |
| 27–35 in (H3) | Gravelly loamy sand | 5.4 | 5% | 79% | 0.5% |
| 35–65 in (H4) | Stratified coarse sand to gravelly sand | 5.4 | 2% | 97% | 0.25% |
What this means
What Riverhead soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Riverhead soils is very strongly acidic: pH 5.0 (most land between 4.8 and 5.2). Most vegetables and lawn grasses do best around 6.0 to 7.0, so lime is often needed; blueberries, azaleas and rhododendrons like it as it is.
Loamy topsoil (loam, silt loam and similar) covers 98% of mapped Riverhead acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is sandy loam (85% of mapped Riverhead acres).
100% of mapped Riverhead acres is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
89% of mapped acres is in hydrologic group A, where water soaks in fast. Lawns there dry out quickly; deeper, less frequent watering and organic matter help.
For a septic system
For conventional septic absorption fields, NRCS rates >99% of the acres in mapped Riverhead 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 Riverhead soil is found
Mapped acres
Riverhead is mapped in New York, New Jersey, Massachusetts and Pennsylvania.
| County | Acres | Share of county land |
|---|---|---|
| Suffolk County, NY | 123,825 | 21.3% |
| Nassau County, NY | 22,177 | 12.1% |
| Morris County, NJ | 11,292 | 3.8% |
| Ulster County, NY | 6,116 | 0.9% |
| Dukes County, MA | 5,942 | 8.8% |
| Passaic County, NJ | 5,918 | 5.0% |
| Westchester County, NY | 4,294 | 1.6% |
| Bergen County, NJ | 3,765 | 2.5% |
| Rensselaer County, NY | 2,814 | 0.7% |
| Sullivan County, NY | 2,370 | 0.4% |
| Nantucket County, MA | 2,230 | 7.3% |
| Delaware County, NY | 2,132 | 0.2% |
| Butler County, PA | 2,090 | 0.4% |
| Orange County, NY | 2,082 | 0.4% |
| Greene County, NY | 1,442 | 0.3% |
| Rockland County, NY | 1,408 | 1.3% |
| Putnam County, NY | 1,344 | 0.9% |
| Albany County, NY | 1,303 | 0.4% |
| Otsego County, NY | 1,172 | 0.2% |
| Queens County, NY | 922 | 1.3% |
| Tioga County, NY | 809 | 0.2% |
| Sussex County, NJ | 743 | 0.2% |
| Hunterdon County, NJ | 604 | 0.2% |
| Kings County, NY | 438 | 0.9% |
| Barnstable County, MA | 309 | 0.1% |
| Somerset County, NJ | 308 | 0.2% |
| Plymouth County, MA | 184 | 0.0% |
| Middlesex County, NJ | 145 | 0.1% |
| Bronx County, NY | 103 | 0.4% |
| New York County, NY | 74 | 0.5% |
| Richmond County, NY | 65 | 0.2% |
| Union County, NJ | 55 | 0.1% |
| Mercer County, NJ | 7 | 0.0% |
| Warren County, NJ | 4 | 0.0% |
Septic absorption fields
NRCS rating, share of Riverhead acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 0.0% |
| Very limited | 99.8% |
| Not rated | 0.2% |
Drainage, water table and flooding
Share of Riverhead acres
- Depth to seasonal high water table
- About 2.6 feet (31 in) (median where reported).
- Flooding
- Not mapped as flooding on most acres.
- Slope
- Typically 2–12% (median 4%).
- Topsoil organic matter
- Median 3%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.3% |
| Somewhat excessively drained | 0.0% |
| Well drained | 99.7% |
| 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) | 88.9% |
| B: moderate infiltration | 10.9% |
| 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 | 0.0% |
| C/D: D as is, C if drained | 0.0% |
| 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 Riverhead (component kind "Series") in SSURGO: 208,485 acres.
- Method
- Shares are by mapped acres of Riverhead components. The profile comes from the single largest Riverhead component. Full methodology.