impermeable

Decades of rapid urban development have encased the city with impermeable concrete surfaces that hinder the natural drainage of water.

Municipal wells typically draw drinking water from hundreds of feet underground, often tapping into aquifers that lie beneath impermeable clay and silt layers called aquitards.

Some options include expanding natural floodplains and removing impermeable pavement from cities — approaches that allow the soil to absorb more rainfall, lessening flood risk, and at the same time stockpiling water underground for future use.

It is the fantasy of an impermeable barrier that allows one’s purity to remain unsullied.

By that they mean, if not quite wiping out the Conservatives, chipping away yet further at what had long seemed impermeable Tory territory primarily in southern England.