environment
Impervious surface
Why this matters
Impervious surface is any hard, sealed surface that water cannot soak through: think roads, parking lots, driveways, sidewalks, and rooftops. The measure tracks the share of land covered by these surfaces. The more pavement and buildings an area has, the less ground is left to absorb rain.
This matters for two big reasons. First, hard surfaces store and radiate heat, so paved-over areas run hotter than green ones. Second, when rain hits pavement instead of soil, it rushes off quickly, picking up oil and chemicals and overwhelming storm drains.
That fast runoff is a leading cause of local flooding, stream erosion, and water pollution. Tracking impervious surface shows where flooding risk and heat are building.
About the Charlotte region
This explorer covers the 14-county, two-state Charlotte region (11 North Carolina and 3 South Carolina counties). Many of these indicators connect to a defining regional story: a landmark Harvard study ranked Charlotte last, 50th of the 50 largest U.S. metros for economic mobility (a child raised in the poorest fifth had about a 4.4% chance of reaching the top fifth), a finding that launched the region's Leading on Opportunity agenda. Updated 2024 data show Charlotte has since climbed to 38th.
Opportunity here is also unevenly mapped. An affluent “wedge” fanning southeast from uptown holds a large majority of the city's wealth on under a quarter of its land, while a ”crescent” to the north, west, and east carries higher poverty, a legacy of redlining, exclusionary zoning, and highway routing that recurs across the race, income, health, tree-canopy, and school maps in this tool. No single indicator is good or bad on its own; together they describe how the region sorted opportunity.
Companion resources: Charlotte-Mecklenburg Quality of Life Explorer · UNC Charlotte Urban Institute · Opportunity Atlas · Methods & sources
Learn more
- U.S. EPA — Soak Up the Rain: What’s the Problem? epa.gov
How pavement and rooftops create polluted runoff and flooding, and what helps.
- USGS — Annual National Land Cover Database usgs.gov
The federal data mapping percent impervious surface across the country.
- U.S. EPA — Reduce Heat Islands epa.gov
How paved, built-up areas trap heat and how green infrastructure cools them.
About the data
Derived from the USGS National Land Cover Database (2001–2021), a 30-metre satellite land-cover product. Tract values are area-weighted zonal statistics (exact pixel fractions) of the classified raster. As a wall-to-wall classification it carries no sampling margin of error.
Source: U.S. Geological Survey, National Land Cover Database (NLCD).