One of the biggest challenges to maintaining stream health is the amount of impervious
surface that is created as an area becomes urbanized.
Each storm drainage bill is calculated by mapping the impervious
area within a parcel to determine the percentage of impervious
surface in relation to the total area of the parcel.
surfaces in urban areas, such as roads, pavements and roofs are thought to be the main cause of water quality degradation and biodiversity loss because they negate the soil and vegetation that would normally soak up rainwater.
The minimum use of impervious
materials allows for more green growth.
Stormwater: Typical development creates impervious
surfaces that do not allow rainwater to infiltrate into the ground and collects.
My wife was beginning to waver but I remained impervious
to Vicky's demands--until my wife and I read her message to Father Christmas: `Please can I have a puppy, signed Vicky.
The RT50X's LCD-based rear-screen projection technology makes it impervious
to image burn during the extended display of static images.
The December 3 issue of NL/NL, which provided coverage of the Philadelphia conference of the Newsletter & Electronic Publishers Association, pointed out three areas that "seem almost impervious
to economic fluctuations"--health care, law, and higher education.
In other words, the materials builders thought were impervious
to corrosion have been infiltrated by moisture in cracks resulting from shrinkage of the cement or movement of the structure."
Polluted runoff from impervious
road surfaces is a major source of environmental and aquatic degradation throughout North America.
The time frame was very much a consequence of the material itself: too much social disruption prior to 1660 renders the Civil War years relatively impervious
to such a careful study, while the decline of church discipline after 1780 would render it less meaningful.
The lightweight synthetic stocks are formed at extreme temperatures and pressures, ensuring that they are impervious
to snow, cold, heat, rain and impact.