Hi Everyone,
A project I'm working on is factory on a rural setting. All roads and parking lots are gravel. Does this account as pervious paving? I'm certain it should, and it should count towards reducing peak discharge (as opposed to a paved road) and also as a water quality BMP. Am I right? Thanks!
Michael DeVuono
Regional Stormwater LeaderArcadis North America
LEEDuser Expert
187 thumbs up
October 14, 2013 - 8:51 am
In regards to 6.1, you are really only worried about the CN for gravel, which is between 76-91 depending on the underlying soil. The lower CN (as opposed to 98 for impervious) will result in lower discharge rates and volume, this is the fundamental concept behind SWM.
A water quality BMP is a feature that treats your surface runoff, a gravel road by itself is not treating anything, especially if it exists in the pre-development. You could do a trench under your parking lot, but without paving above you will have no structural support for vehicles.