Maximum depth of sheet drainage for parking lot
Maximum depth of sheet drainage for parking lot
(OP)
Local codes not withstanding, what is everyone's consensus as to the maximum desirable depth of sheet drainage in a parking lot before putting in an area inlet or island with curb inlet to intercept it? The lot in question is a 500 car high school parking lot, about 5 acres. The existing site is almost square, a 2 percent gradient diagonally, and will need very little grading. The school wants to put in no islands or depressed area inlets and allow it to sheet drain to one corner and dump into a detention pond. Being a government body, they are not required to adhere to local ordinances, expecially for onsite drainage. I think it is too much water for the kids to have to splash through for that long a distance. Has anyone seen design references to this I could show to the school?





RE: Maximum depth of sheet drainage for parking lot
RE: Maximum depth of sheet drainage for parking lot
A 2% parking lot grade is fine for either concrete or asphalt paving. If it is raining, people expect to get wet.
The real question in my mind is, is there enough capacity in the detention pond to prevent back up of the water onto the parking area during the design storm? If there is, then I don't see a problem, if there isn't then the depth of water on the parking lot begins to deepen as the water backsup.
Just make sure there is enough capacity in the pond to accept the design storm without backup onto the pavement.
RE: Maximum depth of sheet drainage for parking lot
RE: Maximum depth of sheet drainage for parking lot
RE: Maximum depth of sheet drainage for parking lot
RE: Maximum depth of sheet drainage for parking lot
RE: Maximum depth of sheet drainage for parking lot
RE: Maximum depth of sheet drainage for parking lot
RE: Maximum depth of sheet drainage for parking lot
RE: Maximum depth of sheet drainage for parking lot
RE: Maximum depth of sheet drainage for parking lot
Have you considered using a slot-drain system to collect and convey the water? Duraslot drains manufactured by ADS (www.ads-pipe.com) are ideally suited to long, consistent grades like you are describing and can be installed for H20 loading.
RE: Maximum depth of sheet drainage for parking lot
RE: Maximum depth of sheet drainage for parking lot
As for kids, i don't think it is an issue unless you have puddle areas which they normally love. On a perfectly graded smooth surface I can't see you getting any of the depths you are worried about.
RE: Maximum depth of sheet drainage for parking lot