MBB138
Civil/Environmental
- Nov 9, 2015
- 6
Hello All,
I wanted to see how everyone handles sediment from offsite undeveloped catchment areas that are tributary to a proposed project site.
I've been told that if your project is located downstream of a hillside/mountain, then you would have to put a sediment basin or design your receiving storm drain system (perhaps a separate system than your onsite storm drain) for bulk flow, which I've seen calculated as your offsite flow rate times a bulking factor of 2. I've never really seen documentation on what triggers the need for either of these measures. Is it dependent on the slope of the offsite terrain? How close do these steep "canyons" or slopes need to be to the site, that would trigger these measures? For example, perhaps mountain drainage is tributary to your site, but it's far away from the site and the terrain shallows out and perhaps deposits the sediment long before it gets to the site. Does anyone have any experience/stories on the subject they can share?
Manuals or software recommendations would also be appreciated. I'd like to have a better understanding of the subject matter.
Thank You,
I wanted to see how everyone handles sediment from offsite undeveloped catchment areas that are tributary to a proposed project site.
I've been told that if your project is located downstream of a hillside/mountain, then you would have to put a sediment basin or design your receiving storm drain system (perhaps a separate system than your onsite storm drain) for bulk flow, which I've seen calculated as your offsite flow rate times a bulking factor of 2. I've never really seen documentation on what triggers the need for either of these measures. Is it dependent on the slope of the offsite terrain? How close do these steep "canyons" or slopes need to be to the site, that would trigger these measures? For example, perhaps mountain drainage is tributary to your site, but it's far away from the site and the terrain shallows out and perhaps deposits the sediment long before it gets to the site. Does anyone have any experience/stories on the subject they can share?
Manuals or software recommendations would also be appreciated. I'd like to have a better understanding of the subject matter.
Thank You,
