"The Chesapeake Bay watershed is adding enough runoff-inducing pavement and buildings every year to completely cover an area the size of Staunton, VA, new data shows.

A recently completed analysis of high-resolution aerial surveys of the six-state watershed finds that the amount of land covered by roads, rooftops, parking lots and other impervious surfaces expanded annually by 13,226 acres, or 20 square miles, from 2013 through 2021.

The rate of increase grew slightly over that 8-year period, the analysis shows. The end result: more than 100,000 acres or about 160 square miles of pavement and hard structures added to the landscape — almost enough to cover Richmond, Norfolk and Hampton, VA, combined.

The data comes from a federally funded effort to map and track changes in land use and land cover across the Bay watershed every four years. Collaborators on the project include the nonprofit Chesapeake Conservancy, the U.S. Geological Survey, University of Vermont and the federal-state Chesapeake Bay Program. 

The surveys, which capture aerial imagery of the landscape at a one-meter resolution, help analysts monitor the conversion of forest and farmland to development. With the help of the University of Maryland Baltimore County, the collaborators also have compiled “hyper-resolution” maps of rivers, streams and wetlands in unprecedented detail.

The finding that impervious surfaces have continued to spread unabated, though, suggests that state and local governments have yet to halt, much less, reverse the harm to the Bay and its tributaries done by development’s hardened footprint. . ."