Hi,
Question one. We are in a semi-arid watershed. In the calculations, we count on 0,75 inch rainfall during 24 hours?
We are planning to clean the rainwater from the roof. Is this credit meant to be for this kind of water or is it only from parking spaces and similar?
Our plan is to put a small sand filter infiltration basin by every well on the roof. Do you think this will work? Do anyone have another suggestion how to clean the water without having some kind of storage volume? We have one well per 100 square meters and the flow will be quite low if we count with a 0,75 in, 24 hour rainfall.
Thanks in advance,
Viktor
Michael DeVuono
Regional Stormwater LeaderArcadis North America
LEEDuser Expert
187 thumbs up
September 2, 2014 - 11:08 am
Hi Victor, Question 1 has been the source of much confusion, and I have received some guidance on this:
The intention was not to ask teams to calculate the 90th percentile storm but the average annual precipitation (then 90% of that amount). They also said those 3 amounts- 1in, 0.75in, and 0.5in- were intended for projects to use if they choose based on which “distinct climate” they fall into (U.S. only. An equivalent would be allowed for projects outside the U.S., but the project would have to show equivalency). So essentially projects could calculate their specific amount or use the applicable one in the footnote.
The intent of the credit is to treat all surface runoff to the 80% TSS standard, I think your approach is viable, have your CE show the treatment in his/her calculations.