Dear all,

I am not quite sure the approach we're using in a zero lot line project is correct to achieve this credit and would like to have your opinion.

The project intends to collect stormwater from the totality of the roofs: part of it will be stored in an underground tank for the irrigation of the terraces (no green roof in the project, the stored part is marginal) and the rest will be discharged in a nearby irrigation canal that streams to farmlands, some kilometers south of the building.

My question is:

Is this kind of approach compliant with the requirements “best replicating natural site hydrology”?

I have one more doubt: with the zero lot line the project can manage the 85th percentile, with the approach above I am managing the 100th percentile of the event, right? 

Thank you so much for any suggestions, advices.