Because impervious surfaces
typically absorb more solar radiation than natural ones do, the water entering streams in urbanized areas can be as much as 6[degrees]C warmer than it would be if the area were undeveloped.
Australia's sensitive and rare endemic water bugs are in decline around our urban fringes because streams and waterways are receiving unnatural runoff from the impervious surfaces
laid in developed areas.
in a watershed," says DigitalGlobe's Chuck Herring.
Development replaces soil and vegetation that once soaked up rainwater and snowmelt with the impervious surfaces
of roofs and roads.
The USGBC offers credit points for exterior landscapes with a minimum of 30 percent of non-roof impervious surfaces
that are shaded (high-albedo materials can be applied to non-roof impervious surfaces
to accentuate the reflectance of installed materials).
Conversion to residential and commercial use is likely to increase impervious surfaces
and soil erosion rates.
Hygiene requires impervious surfaces
that can be washed and do not allow the ingress of dirt.
The old 10-acre portion of the site lacks sufficient impervious surfaces
to collect rain water that has mixed with metals from running off the site.
Storm-water runoff comes from impervious surfaces
such as roofs and parking lots.
As the city of Portland is developed, impervious surfaces
create increased amounts of stormwater runoff during rainfall events, disrupting the natural hydrologic cycle.
This first garden, in eliminating so much pavement, decreases the amount of impervious surfaces
, which in turn improves watershed health, a crucial issue in the Chesapeake Bay region.