As we have 203,000 sqm site area within LEED boundary, with a majority of impervious roof, non-roof driveways, walkways, and landscape areas, basements extend on 100% of site area. We want to achieve 3 points under the mentioned credit option2.
Kindly we want your guidance for the following questions to secure the credit requirement for maximum achievable points.
**1-Percentile storm event:** Can we chose 90th percentile since It's the threshold for 3 points for v4.1, in another word, to achieve 3 points under option 2; Which percentile will we select for the value of "Percentile rainfall depth (mm)" 95th or 90th? so we can use in the calculating for volume to be retained/ collected & reused on-site? (Attachment 1)
**2-LID/GI Documentation **
Adopting LID Design practices: rainwater harvesting/capture and reuse to maintain or restore natural hydrology. There is around **8000 m3** capture capacity, as 6 tanks located in basement2. designed based on 98th percentile (Attachments 2)
Question: Which of the following "water reuse criteria" (A/B/C/D) can be acceptable safely for reviewer to achieve 3 points under credit requirements, So we use collected rainwater in:
A -DCP Cooling tower make up water, which has enormous high demand. **3000 m3/day**
B- Water features such as many of fountains and large basins, terrace swimming pool. As evaporation. Rain Fountains!
C- Exterior Irrigation (attachment 2)
D- Interior Irrigation.
As we have large landscape areas within each entrance with around with **400 m3/day** water demand.
We are in project stage where we can do design change during construction to achieve LEED compliance, your guidance & feedback is very critical to us.
Finance Team
Verte Ltd2 thumbs up
October 9, 2024 - 5:37 am
Hi Ammar,
Regarding your first question you should use the 90th percentile.
You can definately use this water for exterior irrigation, toilet flushing and potentially for option A. Make sure that the post development run off volume is lower comapred to the pre development.