I came across the article at Mother Earth on a way to move away from absolute storage for rainwater collecting to utilizing a series of weep hoses laid into your soil. I’m thinking since one (1) inch of rainfall across a 30’x60′ roof delivers approximately 900 gallons, you must remember that is across the entirety of the roof, and most of us wouldn’t be collecting off but one side. Still, 450+ gallons is more than most would set up for retention. Perhaps a hybrid system where you still utilize rain barrels but set up 2 shut-off valve systems; one to allow for grey water usage in the home, the other during heavy rainfall times to divert as much of it deep into the soil for the garden? Just something to consider.
ILLUSTRATION: ELAYNE SEARS