The loss of pervious cover due to urbanization is a very serious threat to the health and safety of a watershed and all of those people and ecosystems within it. Pervious cover is what regulates the drainage of water through the watershed. Pervious cover includes all natural ground surfaces such as vegetation, soils and porous rock surfaces.
Impervious cover includes manmade surfaces that disallow water infiltration into the ground.
Some examples of impervious cover includes buildings, pavement and even some natural surfaces such as impermeable rock. Similar results along the Shoal Creek basin in Central Austin were reported. To compliment our study, the impervious cover of a random area along the Shoal Creek study area was mapped. This area which encompasses Pease Park goes from near 24th and Lamar down to 15th and Lamar. Preservation of the Pease Park flood plain and its permeable surfaces make this area a fairly balanced area.