Option 1 requires on-site management of the runoff from the developed site for the 95th or 98th percentile of local rainfall events.
According to LEED Glossary, on-site management of the runoff means to capture and retain a specified volume of rainfall to mimic natural hydrologic function.
One of our clients is developing a project that includes a large greenfield area that will remain untouched. Therefore, the hydrologic function of this area will remain as it was before development. However, this is a relatively large area (more than 1 ha) with a slope that drains rain water towards outside of the LEED Boundary.
Is this project eligible to achieve compliance via option 1? The runoff of the above referred greenfield area, despite it being the natural soil’s runoff, it will not be managed on-site.
Thanks in advance