I'm involved in a project (new contruction) within an existing site (airport). The project boundary is quite narrow, a few metres outsite of the building footprint. This means that we don't comply with the 5% landscaping on site, at least not within the project boundary. 

However, i've read that the the vegetated area must cover at least 5% of the project site area (including building footprint, hardscape area, parking footprint, etc.) to be eligible for this credit. I did'n't find the exact definition of the project site area. 

If we take the whole site, the 5% is easily achieved. Would we be eligible if we re-use process water for irrigation of the total site? This means no potable water will be used for irrigation within the project boundary, neither for the whole site. 

Hope to hear from you soon.