Grafton County, New Hampshire
The dominant drainage class is Well drained and the dominant hydrologic group is C (slow infiltration, moderate runoff). This report summarizes the major soil map units across the survey area to help you understand what to expect when buying, building, or gardening in Grafton County, New Hampshire.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Tunbridge-Lyman-Rock outcrop complex, 25 to 60 percent slopes | 64K | Well drained | C | Very limited | Very limited |
| Tunbridge-Lyman-Rock outcrop complex, 15 to 25 percent slopes | 39K | Well drained | C | Very limited | Very limited |
| Water | 25K | Not rated | Not rated | ||
| Monadnock and Hermon soils, 15 to 25 percent slopes, very stony | 25K | Well drained | A | Very limited | Very limited |
| Becket fine sandy loam, 15 to 25 percent slopes, very stony | 19K | Well drained | C | Very limited | Very limited |
| Peru fine sandy loam, 8 to 15 percent slopes, very stony | 19K | Moderately well drained | C/D | Very limited | Very limited |
| Hermon and Monadnock soils, 8 to 15 percent slopes, very stony | 17K | Somewhat excessively drained | A | Somewhat limited | Very limited |
| Tunbridge-Lyman complex, 15 to 25 percent slopes, rocky | 17K | Well drained | C | Very limited | Very limited |
| Becket-Tunbridge association, 15 to 35 percent slopes, very stony | 16K | Well drained | C | Very limited | Very limited |
| Marlow fine sandy loam, 15 to 25 percent slopes, very stony | 15K | Well drained | C | Very limited | Very limited |
| Tunbridge-Lyman-Rock outcrop complex, 8 to 15 percent slopes | 15K | Well drained | C | Very limited | Very limited |
| Marlow-Tunbridge association, hilly, very stony | 13K | Well drained | C | Very limited | Very limited |
| Pillsbury fine sandy loam, 0 to 8 percent slopes, very stony | 13K | Poorly drained | D | Very limited | Very limited |
| Becket-Monadnock association, 15 to 35 percent slopes, very stony | 13K | Well drained | C | Very limited | Very limited |
| Adams loamy sand, 15 to 60 percent slopes | 12K | Excessively drained | A | Very limited | Very limited |
| Monadnock-Hermon association, 15 to 35 percent slopes, very stony | 11K | Well drained | B | Very limited | Very limited |
| Berkshire fine sandy loam, 15 to 25 percent slopes, very stony | 11K | Well drained | B | Very limited | Very limited |
| Tunbridge-Lyman complex, 8 to 15 percent slopes, rocky | 10K | Well drained | C | Very limited | Very limited |
| Monadnock and Hermon soils, 25 to 35 percent slopes, very stony | 10K | Well drained | A | Very limited | Very limited |
| Cardigan-Kearsarge-Rock outcrop complex, 15 to 25 percent slopes | 10K | Well drained | C | Very limited | Very limited |
What This Means
Building & Foundations
About 88% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, poor drainage in some areas. A geotechnical assessment is recommended before building.
Septic Systems
About 93% of soils are rated "very limited" for septic absorption fields. Despite good drainage overall, limitations may stem from shallow bedrock, steep slopes, or seasonal conditions. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Well-drained soils on sloped terrain — good for most plants but watch for erosion. Terracing, contour planting, and mulching help retain moisture and topsoil. Drip irrigation is more effective than sprinklers on slopes.