Massachusetts: basement moisture and foundation risk by county
14 counties, ranked by our combined index. Highest combined risk is Nantucket County (41), lowest is Berkshire County (31). The worst soil for foundation cracks specifically is in Nantucket County.
| County | Index | Moisture | Cracks | Water table | Region |
|---|---|---|---|---|---|
| Nantucket County | 41 | 42 | 35 | 46 | Atlantic coastal plain |
| Norfolk County | 41 | 39 | 25 | 66 | Glaciated New England upland |
| Suffolk County | 39 | 41 | 16 | 66 | Glaciated New England upland |
| Essex County | 38 | 40 | 14 | 66 | Glaciated New England upland |
| Franklin County | 38 | 44 | 25 | 46 | Glaciated New England upland |
| Barnstable County | 35 | 41 | 20 | 46 | Atlantic coastal plain |
| Middlesex County | 35 | 43 | 15 | 46 | Glaciated New England upland |
| Worcester County | 35 | 41 | 18 | 46 | Glaciated New England upland |
| Dukes County | 34 | 42 | 15 | 46 | Atlantic coastal plain |
| Hampden County | 34 | 39 | 31 | 30 | Glaciated New England upland |
| Hampshire County | 34 | 39 | 29 | 30 | Glaciated New England upland |
| Plymouth County | 34 | 41 | 16 | 46 | Atlantic coastal plain |
| Berkshire County | 31 | 41 | 18 | 30 | Glaciated New England upland |
| Bristol County | 31 | 39 | 19 | 30 | Glaciated New England upland |
Values from USDA NRCS SSURGO where available, otherwise our regional model — each county page states which. Methodology.
The physiographic regions inside Massachusetts
State lines are political; soil follows geology. These are the distinct ground types inside Massachusetts and why each behaves the way it does.
Glaciated New England upland
A hardpan under thin till creates a perched water table — water stands above an impermeable layer even though the regional water table is deep. It is the commonest cause of a wet basement in New England. Expansive clay is largely absent.
10 counties: Berkshire County, Bristol County, Essex County, Franklin County, Hampden County, Hampshire County, Middlesex County, Norfolk County, Suffolk County, Worcester County
Atlantic coastal plain
Extremely variable over short distances: sand and saturated clay side by side. A county figure means less here than anywhere else we cover — the individual parcel decides.
4 counties: Barnstable County, Dukes County, Nantucket County, Plymouth County
Page data updated