Attitudes towards rain as a nuisance ("stormwater" is a pejorative term) or instead as a life-giving precious blessing (rain/water) are both self-fulfilling prophecies. We pick the second attitude. Our goal is that the hydrology of the site be nearly indistinguishable from that of the temperate forest that previously occupied this site and its surroundings. To that end rainfall is collected to be stored & used to support living processes, often several of them, before leaving the site.
Smog, bird droppings, and pollen are easily removed to create pristine water without chemical hormones, pharmaceuticals, fluoride, chlorine or Cr6), while maintaining some nutrients living bodies can benefit from. Tap water with added chlorine to kill pathogens does not make great irrigation water either, because it is a biocide.
