Permeable areas

That's an interesting question and I dare say the answer won't be entirely black & white. I think it fundamentally requires you to ask yourself what the intent of the specific area is. A gravel parking lot, for example, is not landscaped area, nor would it be irrigated in a 'conventional' scenario. On the other hand, if the gravel area is part of the functional landscaping (I'm thinking here of something akin to xeriscaping) and the gravel ostensibly replaces what might otherwise be turf grass on a more conventional site, then yes, I would include it. It really comes down to what purpose the gravel area serves. Hope that helps, Dan