C&G Inlet Design
C&G Inlet Design
(OP)
Hello, I need some help. I'm trying to design the proper number of curb inlets to drain a street. The street is 300' long on a 2.3% longitudinal slope with a 2% cross slope. Standard 30" c&g. The curb inlets have a 4' opening. The north side of the street is approx. 2 acres and drains over the curb and into the street. The design is for the 10 year storm. Using the rational method I get 5.5 cfs at the peak flow. I am coming up with 5 inlets needed. This sounds like a lot for such a short street. Any help out there? Thanks, Herb





RE: C&G Inlet Design
RE: C&G Inlet Design
Thanks
RE: C&G Inlet Design
RE: C&G Inlet Design
How wide is the road and right of way? Is there off site flow?
For a 300 foot stretch of 4 lane road plus median, each at 12 feet, I get an area of 18,000 square feet=0.4 acres.
With C=0.98 and i=6 inches, the flow rate is 2.4 cfs.
RE: C&G Inlet Design
DA=2.0
c=0.4
I=7.22
RE: C&G Inlet Design
RE: C&G Inlet Design
RE: C&G Inlet Design
The smart thing to do here, if you have the ability, is to use a ditch or swale or low point up-gradient of the street and catch all that non-street drainage in a pedistal top inlet or headwall before it ends up in your gutter pan. That will dramatically reduce the number of structures you need in your street.
I would use a pedestal top inlet for something like this. Those still keep neighborhood kids out of the storm drain system but have a very low chance of clogging.
Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com
RE: C&G Inlet Design
RE: C&G Inlet Design
Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com