Virginia: basement moisture and foundation risk by county
133 counties, ranked by our combined index. Highest combined risk is Hampton City (51), lowest is Botetourt County (24). The worst soil for foundation cracks specifically is in Shenandoah County.
| County | Index | Moisture | Cracks | Water table | Region |
|---|---|---|---|---|---|
| Hampton City | 51 | 41 | 43 | 82 | Southern Atlantic Coastal Plain |
| Suffolk City | 49 | 40 | 48 | 66 | Southern Atlantic Coastal Plain |
| Surry County | 49 | 41 | 47 | 66 | Southern Atlantic Coastal Plain |
| Accomack County | 48 | 43 | 43 | 66 | Southern Atlantic Coastal Plain |
| James City County | 48 | 43 | 32 | 82 | Southern Atlantic Coastal Plain |
| Albemarle County | 47 | 39 | 60 | 46 | Piedmont |
| Dinwiddie County | 47 | 37 | 62 | 46 | Piedmont |
| Orange County | 47 | 37 | 61 | 46 | Piedmont |
| Poquoson City | 47 | 43 | 39 | 66 | Southern Atlantic Coastal Plain |
| Amelia County | 46 | 37 | 60 | 46 | Piedmont |
| Giles County | 46 | 38 | 57 | 46 | Ridge and Valley |
| Middlesex County | 46 | 40 | 40 | 66 | Southern Atlantic Coastal Plain |
| Westmoreland County | 46 | 43 | 49 | 46 | Southern Atlantic Coastal Plain |
| Grayson County | 45 | 35 | 57 | 46 | Ridge and Valley |
| King and Queen County | 45 | 42 | 47 | 46 | Southern Atlantic Coastal Plain |
| Petersburg City | 45 | 36 | 57 | 46 | Piedmont |
| Southampton County | 45 | 38 | 66 | 30 | Piedmont |
| Winchester City | 45 | 38 | 55 | 46 | Piedmont |
| Isle of Wight County | 44 | 44 | 42 | 46 | Southern Atlantic Coastal Plain |
| Lunenburg County | 44 | 34 | 57 | 46 | Piedmont |
| Madison County | 44 | 39 | 61 | 30 | Piedmont |
| Manassas City | 44 | 35 | 56 | 46 | Piedmont |
| Powhatan County | 44 | 38 | 62 | 30 | Piedmont |
| Virginia Beach City | 44 | 41 | 48 | 46 | Southern Atlantic Coastal Plain |
| York County | 44 | 42 | 30 | 66 | Southern Atlantic Coastal Plain |
| Appomattox County | 43 | 38 | 60 | 30 | Piedmont |
| Bland County | 43 | 34 | 54 | 46 | Ridge and Valley |
| Clarke County | 43 | 38 | 59 | 30 | Piedmont |
| Fairfax City | 43 | 38 | 49 | 46 | Piedmont |
| Gloucester County | 43 | 41 | 44 | 46 | Southern Atlantic Coastal Plain |
| Greensville County | 43 | 34 | 65 | 30 | Piedmont |
| Hanover County | 43 | 37 | 62 | 30 | Piedmont |
| Northumberland County | 43 | 43 | 26 | 66 | Southern Atlantic Coastal Plain |
| Page County | 43 | 36 | 62 | 30 | Piedmont |
| Scott County | 43 | 36 | 52 | 46 | Appalachian Plateau |
| Shenandoah County | 43 | 34 | 66 | 30 | Piedmont |
| Spotsylvania County | 43 | 37 | 61 | 30 | Piedmont |
| Buckingham County | 42 | 36 | 58 | 30 | Piedmont |
| Charles City County | 42 | 39 | 43 | 46 | Piedmont |
| Tazewell County | 42 | 33 | 52 | 46 | Appalachian Plateau |
| Wise County | 42 | 36 | 46 | 46 | Appalachian Plateau |
| Wythe County | 42 | 36 | 49 | 46 | Ridge and Valley |
| Fairfax County | 41 | 38 | 43 | 46 | Piedmont |
| Falls Church City | 41 | 36 | 44 | 46 | Piedmont |
| Fredericksburg City | 41 | 38 | 63 | 16 | Piedmont |
| Prince George County | 41 | 35 | 47 | 46 | Piedmont |
| Bristol City | 40 | 34 | 44 | 46 | Appalachian Plateau |
| Buchanan County | 40 | 37 | 51 | 30 | Appalachian Plateau |
| Colonial Heights City | 40 | 39 | 50 | 30 | Piedmont |
| Essex County | 40 | 41 | 20 | 66 | Southern Atlantic Coastal Plain |
| Floyd County | 40 | 34 | 56 | 30 | Ridge and Valley |
| Harrisonburg City | 40 | 36 | 42 | 46 | Piedmont |
| New Kent County | 40 | 43 | 30 | 46 | Southern Atlantic Coastal Plain |
| Newport News City | 40 | 43 | 16 | 66 | Southern Atlantic Coastal Plain |
| Portsmouth City | 40 | 42 | 34 | 46 | Southern Atlantic Coastal Plain |
| Williamsburg City | 40 | 41 | 34 | 46 | Southern Atlantic Coastal Plain |
| Alexandria City | 39 | 38 | 36 | 46 | Piedmont |
| Brunswick County | 39 | 39 | 55 | 16 | Piedmont |
| Cumberland County | 39 | 36 | 39 | 46 | Piedmont |
| Fauquier County | 39 | 35 | 50 | 30 | Piedmont |
| Norfolk City | 39 | 43 | 28 | 46 | Southern Atlantic Coastal Plain |
| Northampton County | 39 | 40 | 34 | 46 | Southern Atlantic Coastal Plain |
| Patrick County | 39 | 34 | 53 | 30 | Ridge and Valley |
| Pittsylvania County | 39 | 34 | 41 | 46 | Blue Ridge Mountains |
| Richmond City | 39 | 35 | 52 | 30 | Piedmont |
| Salem City | 39 | 36 | 49 | 30 | Ridge and Valley |
| Smyth County | 39 | 36 | 51 | 30 | Appalachian Plateau |
| Warren County | 39 | 38 | 34 | 46 | Piedmont |
| Arlington County | 38 | 35 | 37 | 46 | Piedmont |
| Chesapeake City | 38 | 40 | 28 | 46 | Southern Atlantic Coastal Plain |
| Emporia City | 38 | 34 | 48 | 30 | Piedmont |
| Frederick County | 38 | 34 | 60 | 16 | Piedmont |
| Lee County | 38 | 35 | 35 | 46 | Appalachian Plateau |
| Lynchburg City | 38 | 34 | 39 | 46 | Blue Ridge Mountains |
| Mecklenburg County | 38 | 35 | 57 | 16 | Piedmont |
| Stafford County | 38 | 39 | 43 | 30 | Piedmont |
| Covington City | 37 | 30 | 39 | 46 | Blue Ridge Mountains |
| Dickenson County | 37 | 38 | 28 | 46 | Appalachian Plateau |
| Goochland County | 37 | 37 | 43 | 30 | Piedmont |
| Hopewell City | 37 | 34 | 57 | 16 | Piedmont |
| King William County | 37 | 34 | 36 | 46 | Piedmont |
| Lancaster County | 37 | 42 | 23 | 46 | Southern Atlantic Coastal Plain |
| Louisa County | 37 | 35 | 46 | 30 | Piedmont |
| Nottoway County | 37 | 38 | 42 | 30 | Piedmont |
| Pulaski County | 37 | 34 | 35 | 46 | Ridge and Valley |
| Rockingham County | 37 | 34 | 35 | 46 | Piedmont |
| Charlottesville City | 36 | 35 | 30 | 46 | Piedmont |
| Culpeper County | 36 | 38 | 36 | 30 | Piedmont |
| Fluvanna County | 36 | 37 | 39 | 30 | Piedmont |
| Greene County | 36 | 35 | 43 | 30 | Piedmont |
| Henrico County | 36 | 39 | 36 | 30 | Piedmont |
| Montgomery County | 36 | 37 | 40 | 30 | Ridge and Valley |
| Rappahannock County | 36 | 35 | 30 | 46 | Piedmont |
| Alleghany County | 35 | 33 | 41 | 30 | Blue Ridge Mountains |
| Campbell County | 35 | 32 | 30 | 46 | Blue Ridge Mountains |
| Carroll County | 35 | 34 | 41 | 30 | Ridge and Valley |
| Chesterfield County | 35 | 38 | 35 | 30 | Piedmont |
| Galax City | 35 | 35 | 39 | 30 | Ridge and Valley |
| Mathews County | 35 | 41 | 19 | 46 | Southern Atlantic Coastal Plain |
| Norton City | 35 | 34 | 40 | 30 | Appalachian Plateau |
| Rockbridge County | 35 | 33 | 40 | 30 | Blue Ridge Mountains |
| Bedford City | 34 | 31 | 40 | 30 | Blue Ridge Mountains |
| Caroline County | 34 | 39 | 40 | 16 | Piedmont |
| Franklin County | 34 | 31 | 31 | 46 | Blue Ridge Mountains |
| Prince Edward County | 34 | 36 | 33 | 30 | Piedmont |
| Roanoke County | 34 | 33 | 26 | 46 | Blue Ridge Mountains |
| Washington County | 34 | 35 | 36 | 30 | Appalachian Plateau |
| Charlotte County | 33 | 37 | 30 | 30 | Piedmont |
| King George County | 33 | 34 | 43 | 16 | Piedmont |
| Prince William County | 33 | 38 | 39 | 16 | Piedmont |
| Radford City | 33 | 36 | 32 | 30 | Ridge and Valley |
| Roanoke City | 33 | 31 | 26 | 46 | Blue Ridge Mountains |
| Amherst County | 32 | 31 | 22 | 46 | Blue Ridge Mountains |
| Bedford County | 32 | 33 | 22 | 46 | Blue Ridge Mountains |
| Loudoun County | 32 | 38 | 36 | 16 | Piedmont |
| Martinsville City | 32 | 31 | 36 | 30 | Blue Ridge Mountains |
| Nelson County | 32 | 32 | 34 | 30 | Blue Ridge Mountains |
| Danville City | 31 | 34 | 26 | 30 | Blue Ridge Mountains |
| Halifax County | 31 | 34 | 17 | 46 | Blue Ridge Mountains |
| Highland County | 31 | 29 | 36 | 30 | Blue Ridge Mountains |
| Sussex County | 31 | 39 | 29 | 16 | Piedmont |
| Craig County | 30 | 38 | 29 | 16 | Ridge and Valley |
| Franklin City | 30 | 30 | 39 | 16 | Blue Ridge Mountains |
| Richmond County | 30 | 34 | 35 | 16 | Piedmont |
| Waynesboro City | 30 | 30 | 30 | 30 | Blue Ridge Mountains |
| Buena Vista City | 29 | 30 | 26 | 30 | Blue Ridge Mountains |
| Russell County | 29 | 35 | 30 | 16 | Appalachian Plateau |
| Bath County | 28 | 29 | 34 | 16 | Blue Ridge Mountains |
| Henry County | 28 | 33 | 18 | 30 | Blue Ridge Mountains |
| Lexington City | 28 | 32 | 21 | 30 | Blue Ridge Mountains |
| Staunton City | 27 | 30 | 22 | 30 | Blue Ridge Mountains |
| Augusta County | 26 | 31 | 16 | 30 | Blue Ridge Mountains |
| Botetourt County | 24 | 31 | 19 | 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 Virginia
State lines are political; soil follows geology. These are the distinct ground types inside Virginia and why each behaves the way it does.
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.
59 counties: Albemarle County, Alexandria City, Amelia County, Appomattox County, Arlington County, Brunswick County, Buckingham County, Caroline County, Charles City County, Charlotte County, Charlottesville City, Chesterfield County, Clarke County, Colonial Heights City, Culpeper County, Cumberland County, Dinwiddie County, Emporia City, Fairfax County, Fairfax City, Falls Church City, Fauquier County, Fluvanna County, Frederick County, Fredericksburg City, Goochland County, Greene County, Greensville County, Hanover County, Harrisonburg City, Henrico County, Hopewell City, King George County, King William County, Loudoun County, Louisa County, Lunenburg County, Madison County, Manassas City, Mecklenburg County, Nottoway County, Orange County, Page County, Petersburg City, Powhatan County, Prince Edward County, Prince George County, Prince William County, Rappahannock County, Richmond County, Richmond City, Rockingham County, Shenandoah County, Southampton County, Spotsylvania County, Stafford County, Sussex County, Warren County, Winchester City
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.
26 counties: Alleghany County, Amherst County, Augusta County, Bath County, Bedford County, Bedford City, Botetourt County, Buena Vista City, Campbell County, Covington City, Danville City, Franklin County, Franklin City, Halifax County, Henry County, Highland County, Lexington City, Lynchburg City, Martinsville City, Nelson County, Pittsylvania County, Roanoke County, Roanoke City, Rockbridge County, Staunton City, Waynesboro City
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.
24 counties: Accomack County, Chesapeake City, Essex County, Gloucester County, Hampton City, Isle of Wight County, James City County, King and Queen County, Lancaster County, Mathews County, Middlesex County, New Kent County, Newport News City, Norfolk City, Northampton County, Northumberland County, Poquoson City, Portsmouth City, Suffolk City, Surry County, Virginia Beach City, Westmoreland County, Williamsburg City, York County
Ridge and Valley
Limestone valleys mean karst: permeability is excellent until it is not. Sinkhole activity is an underrated cause of foundation failure here.
13 counties: Bland County, Carroll County, Craig County, Floyd County, Galax City, Giles County, Grayson County, Montgomery County, Patrick County, Pulaski County, Radford City, Salem City, Wythe County
Appalachian Plateau
Water travels over bedrock under a thin skin of colluvium. A house cut into a hillside has an entire catchment behind its uphill wall — what decides the outcome here is a daylight drain, not a coating.
11 counties: Bristol City, Buchanan County, Dickenson County, Lee County, Norton City, Russell County, Scott County, Smyth County, Tazewell County, Washington County, Wise County
Page data updated