North Carolina: basement moisture and foundation risk by county
100 counties, ranked by our combined index. Highest combined risk is Moore County (53), lowest is Buncombe County (25). The worst soil for foundation cracks specifically is in Cleveland County.
| County | Index | Moisture | Cracks | Water table | Region |
|---|---|---|---|---|---|
| Moore County | 53 | 42 | 47 | 82 | Southern Atlantic Coastal Plain |
| Scotland County | 53 | 43 | 46 | 82 | Southern Atlantic Coastal Plain |
| Robeson County | 52 | 40 | 47 | 82 | Southern Atlantic Coastal Plain |
| Johnston County | 51 | 44 | 39 | 82 | Southern Atlantic Coastal Plain |
| Beaufort County | 50 | 43 | 47 | 66 | Southern Atlantic Coastal Plain |
| Bertie County | 50 | 42 | 37 | 82 | Southern Atlantic Coastal Plain |
| Caswell County | 50 | 44 | 34 | 82 | Southern Atlantic Coastal Plain |
| Currituck County | 49 | 44 | 33 | 82 | Southern Atlantic Coastal Plain |
| Forsyth County | 48 | 38 | 64 | 46 | Piedmont |
| Hoke County | 48 | 42 | 44 | 66 | Southern Atlantic Coastal Plain |
| Gates County | 47 | 41 | 43 | 66 | Southern Atlantic Coastal Plain |
| Montgomery County | 47 | 38 | 61 | 46 | Piedmont |
| New Hanover County | 47 | 42 | 39 | 66 | Southern Atlantic Coastal Plain |
| Pasquotank County | 47 | 43 | 40 | 66 | Southern Atlantic Coastal Plain |
| Rockingham County | 47 | 42 | 30 | 82 | Southern Atlantic Coastal Plain |
| Columbus County | 46 | 42 | 25 | 82 | Southern Atlantic Coastal Plain |
| Lee County | 46 | 43 | 37 | 66 | Southern Atlantic Coastal Plain |
| Randolph County | 46 | 43 | 36 | 66 | Southern Atlantic Coastal Plain |
| Tyrrell County | 46 | 42 | 36 | 66 | Southern Atlantic Coastal Plain |
| Wake County | 46 | 40 | 41 | 66 | Southern Atlantic Coastal Plain |
| Chatham County | 45 | 42 | 24 | 82 | Southern Atlantic Coastal Plain |
| Chowan County | 45 | 44 | 47 | 46 | Southern Atlantic Coastal Plain |
| Cleveland County | 45 | 38 | 65 | 30 | Piedmont |
| Duplin County | 45 | 41 | 49 | 46 | Southern Atlantic Coastal Plain |
| Granville County | 45 | 43 | 48 | 46 | Southern Atlantic Coastal Plain |
| Hyde County | 45 | 41 | 34 | 66 | Southern Atlantic Coastal Plain |
| Perquimans County | 45 | 43 | 33 | 66 | Southern Atlantic Coastal Plain |
| Richmond County | 45 | 42 | 48 | 46 | Southern Atlantic Coastal Plain |
| Vance County | 45 | 44 | 46 | 46 | Southern Atlantic Coastal Plain |
| Washington County | 45 | 41 | 24 | 82 | Southern Atlantic Coastal Plain |
| Craven County | 44 | 44 | 44 | 46 | Southern Atlantic Coastal Plain |
| Ashe County | 43 | 37 | 48 | 46 | Piedmont |
| Bladen County | 43 | 42 | 28 | 66 | Southern Atlantic Coastal Plain |
| Brunswick County | 43 | 41 | 17 | 82 | Southern Atlantic Coastal Plain |
| Cumberland County | 43 | 40 | 32 | 66 | Southern Atlantic Coastal Plain |
| Durham County | 43 | 43 | 25 | 66 | Southern Atlantic Coastal Plain |
| Greene County | 43 | 40 | 30 | 66 | Southern Atlantic Coastal Plain |
| Guilford County | 43 | 36 | 52 | 46 | Piedmont |
| Lincoln County | 43 | 36 | 61 | 30 | Piedmont |
| Martin County | 43 | 40 | 30 | 66 | Southern Atlantic Coastal Plain |
| Nash County | 43 | 40 | 19 | 82 | Southern Atlantic Coastal Plain |
| Pender County | 43 | 44 | 24 | 66 | Southern Atlantic Coastal Plain |
| Surry County | 43 | 35 | 63 | 30 | Piedmont |
| Warren County | 43 | 43 | 25 | 66 | Southern Atlantic Coastal Plain |
| Wilson County | 43 | 41 | 45 | 46 | Southern Atlantic Coastal Plain |
| Onslow County | 42 | 41 | 40 | 46 | Southern Atlantic Coastal Plain |
| Orange County | 42 | 40 | 43 | 46 | Southern Atlantic Coastal Plain |
| Watauga County | 42 | 35 | 61 | 30 | Piedmont |
| Wilkes County | 42 | 36 | 48 | 46 | Piedmont |
| Franklin County | 41 | 40 | 23 | 66 | Southern Atlantic Coastal Plain |
| Halifax County | 41 | 43 | 34 | 46 | Southern Atlantic Coastal Plain |
| Wayne County | 41 | 41 | 22 | 66 | Southern Atlantic Coastal Plain |
| Alamance County | 40 | 44 | 17 | 66 | Southern Atlantic Coastal Plain |
| Cabarrus County | 40 | 36 | 41 | 46 | Piedmont |
| Harnett County | 40 | 43 | 17 | 66 | Southern Atlantic Coastal Plain |
| Jones County | 40 | 43 | 32 | 46 | Southern Atlantic Coastal Plain |
| Lenoir County | 40 | 43 | 30 | 46 | Southern Atlantic Coastal Plain |
| Person County | 40 | 41 | 21 | 66 | Southern Atlantic Coastal Plain |
| Stokes County | 40 | 34 | 57 | 30 | Piedmont |
| Alleghany County | 39 | 38 | 36 | 46 | Piedmont |
| Dare County | 39 | 44 | 26 | 46 | Southern Atlantic Coastal Plain |
| Davidson County | 39 | 36 | 38 | 46 | Piedmont |
| Hertford County | 39 | 42 | 30 | 46 | Southern Atlantic Coastal Plain |
| Yadkin County | 39 | 39 | 44 | 30 | Piedmont |
| Camden County | 38 | 41 | 29 | 46 | Southern Atlantic Coastal Plain |
| Pitt County | 38 | 41 | 29 | 46 | Southern Atlantic Coastal Plain |
| Rowan County | 38 | 34 | 48 | 30 | Piedmont |
| Rutherford County | 38 | 38 | 33 | 46 | Piedmont |
| Stanly County | 38 | 37 | 44 | 30 | Piedmont |
| Alexander County | 37 | 34 | 57 | 16 | Piedmont |
| Carteret County | 37 | 44 | 20 | 46 | Southern Atlantic Coastal Plain |
| Cherokee County | 37 | 32 | 39 | 46 | Blue Ridge Mountains |
| Graham County | 37 | 32 | 39 | 46 | Blue Ridge Mountains |
| Sampson County | 37 | 43 | 22 | 46 | Southern Atlantic Coastal Plain |
| Union County | 37 | 35 | 32 | 46 | Piedmont |
| Anson County | 36 | 36 | 41 | 30 | Piedmont |
| Caldwell County | 36 | 35 | 43 | 30 | Piedmont |
| Edgecombe County | 36 | 41 | 22 | 46 | Southern Atlantic Coastal Plain |
| Macon County | 36 | 32 | 33 | 46 | Blue Ridge Mountains |
| Pamlico County | 36 | 43 | 20 | 46 | Southern Atlantic Coastal Plain |
| Iredell County | 35 | 38 | 44 | 16 | Piedmont |
| Northampton County | 35 | 43 | 17 | 46 | Southern Atlantic Coastal Plain |
| Polk County | 35 | 31 | 34 | 46 | Blue Ridge Mountains |
| Avery County | 34 | 38 | 30 | 30 | Piedmont |
| Catawba County | 34 | 35 | 45 | 16 | Piedmont |
| Gaston County | 34 | 38 | 41 | 16 | Piedmont |
| Mitchell County | 34 | 30 | 32 | 46 | Blue Ridge Mountains |
| Burke County | 33 | 34 | 34 | 30 | Piedmont |
| Mecklenburg County | 33 | 37 | 30 | 30 | Piedmont |
| Yancey County | 32 | 31 | 36 | 30 | Blue Ridge Mountains |
| Haywood County | 31 | 31 | 33 | 30 | Blue Ridge Mountains |
| Davie County | 30 | 38 | 30 | 16 | Piedmont |
| Madison County | 30 | 30 | 29 | 30 | Blue Ridge Mountains |
| McDowell County | 30 | 30 | 18 | 46 | Blue Ridge Mountains |
| Henderson County | 29 | 30 | 26 | 30 | Blue Ridge Mountains |
| Clay County | 28 | 34 | 29 | 16 | Blue Ridge Mountains |
| Transylvania County | 28 | 34 | 18 | 30 | Blue Ridge Mountains |
| Swain County | 27 | 32 | 17 | 30 | Blue Ridge Mountains |
| Jackson County | 26 | 31 | 26 | 16 | Blue Ridge Mountains |
| Buncombe County | 25 | 33 | 20 | 16 | Blue Ridge Mountains |
Values from USDA NRCS SSURGO where available, otherwise our regional model — each county page states which. Methodology.
The physiographic regions inside North Carolina
State lines are political; soil follows geology. These are the distinct ground types inside North Carolina and why each behaves the way it does.
Southern Atlantic Coastal Plain
Low, flat and wet. Groundwater sits close to the surface for much of the year, which is why houses here sit on slabs or piers rather than over basements. Where clays are present they are moderately expansive; where sand dominates, the risk is moisture, not movement.
57 counties: Alamance County, Beaufort County, Bertie County, Bladen County, Brunswick County, Camden County, Carteret County, Caswell County, Chatham County, Chowan County, Columbus County, Craven County, Cumberland County, Currituck County, Dare County, Duplin County, Durham County, Edgecombe County, Franklin County, Gates County, Granville County, Greene County, Halifax County, Harnett County, Hertford County, Hoke County, Hyde County, Johnston County, Jones County, Lee County, Lenoir County, Martin County, Moore County, Nash County, New Hanover County, Northampton County, Onslow County, Orange County, Pamlico County, Pasquotank County, Pender County, Perquimans County, Person County, Pitt County, Randolph County, Richmond County, Robeson County, Rockingham County, Sampson County, Scotland County, Tyrrell County, Vance County, Wake County, Warren County, Washington County, Wayne County, Wilson County
Piedmont
Saprolite is weathered rock that keeps its structure, so water moves through it along relict joints unpredictably. The Triassic basins inside the Piedmont are islands of strongly expansive clay.
28 counties: Alexander County, Alleghany County, Anson County, Ashe County, Avery County, Burke County, Cabarrus County, Caldwell County, Catawba County, Cleveland County, Davidson County, Davie County, Forsyth County, Gaston County, Guilford County, Iredell County, Lincoln County, Mecklenburg County, Montgomery County, Rowan County, Rutherford County, Stanly County, Stokes County, Surry County, Union County, Watauga County, Wilkes County, Yadkin County
Blue Ridge Mountains
Steep ground with deep weathering. Volume change is low, but slope stability is not: colluvium on a mountainside can creep, and debris flows during hurricane rainfall are a documented hazard. A house benched into a slope collects water behind its uphill wall.
15 counties: Buncombe County, Cherokee County, Clay County, Graham County, Haywood County, Henderson County, Jackson County, Macon County, Madison County, McDowell County, Mitchell County, Polk County, Swain County, Transylvania County, Yancey County
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