Hi all,

I'm working on a project that is pursuing LEED certification. Stormwater management strategy will be based on the collection of runoff from the roofs in order to reuse it later for irrigation, WC flushes, etc (the water will be stored in cisterns).

My doubt is how can the contribute of the collected water be accounted for the intent of this credit. I think that the way to do this is to estimate the amount of harvested water volume and compare it with the water needs for irrigation and flush discharges. If water needs are higher than the collected volume is it reasonable to consider that all the harvested water will be retained? Or is it needed to ensure that a permanent detention volume is available, what can lead to water discharge for the municipal drainage system, not accounted as retained?

Kind regards,