Hello there. My team and I are certifying a building in Brazilia, Brazil. I would like to check if I'm right about the procedure to accomplish SSc6.

1) Find the average weather year precipitation;
2) Separete all areas of the total site (example: asphalt, concrete, brick, ...)
3) Calculate the total runoff volume (Q = C i A): sum all Q's from all different types of areas
4) Calculate the volume of captured runoff by a cistern
5) Evaluate the minimum drawdown rate
6) Evaluate if the volume of captured runoff is bigger than 15% of the total runoff volume.

Is that all right?

Just to check, if the ratio between impervious area and green area is equal to 5, I don't need to worry about cisterns, right?

By the way, how am I supposed to extimate the rainfall event interval?

And the last question is: average rainfall event = total precipitation / number of rainfalls ?

Thank you so much!! God bless you all.