All around it is limestone, which anyone who has studied geography at school will know is pervious and water disappears through it.
The City of Seattle currently credits pervious surfaces as stormwater management reduction.
Recently, our regional promotion groups have identified what they think of as emerging opportunity in the area of pervious pavements.
The top sheet is formed of a fluid pervious material, e.g., a fibrous material.
The brownfield site had no trees or pervious surfaces, and it generated a range of environmental problems for the surrounding neighborhood.
The use of impervious surfaces (like pavement and concrete) can be minimized and replaced with pervious surfaces (like stone and gravel) whenever possible.
Because of the very low water-cement ratio and the open matrix that allows air movement through the concrete matrix, pervious concrete can dry out very quickly.
A green sod roof reduces runoff from impermeable surfaces, while a pervious parking lot allows infiltration of water into the ground.
The parking lot uses pervious limestone and is landscaped with indigenous plants.
A typical cubic yard of pervious concrete would have 2650 pounds of #89 gravel, 600 pounds of portland cement, and a water-cement ratio of about 0.30.