With these simple-to-install tiles adhesive-bonded to the windward walls of new and existing buildings, the entire surface becomes the collector of rainwater. Furthermore, the rainwater is purified as it drips through the pervious concrete (which is loaded with TiO2 photocatalyst).
Form follows Function:
One of the best features here is that the porous material, combined with the decorative shape of the tile causes the rain water to channel down the wall at the same time as being filtered until it arrives at storage tanks at the bottom of the wall. This is accomplished without any complicated mechanical means or expensive, high-tech materials.
These tiles are simply poured using straightforward molds and can be made anywhere in the world, even on site. Note that the back of the tile is made less porous for effective adhesive application by simply adding sand (and, optionally, silicone) to the aggregate mix.
This unique material can be used in all kinds of applications for water control and collection. In additional to being for application to vertical walls, This material can also retrofit ugly horizontal concrete surfaces such as sidewalks, driveways, and parking lots.
In summary, these tiles turn existing waterproof surfaces into effective and inexpensive water catchment surfaces.
Have a look: http://www.perviouspavement.org/