does storm inlet have Q discharge capacity?
does storm inlet have Q discharge capacity?
(OP)
if I calculate the Q of a given area draining to an area inlet like the pic.
Inlet is standard install by county. Does this inlet have Q capacity?
Inlet is standard install by county. Does this inlet have Q capacity?





RE: does storm inlet have Q discharge capacity?
https://www.codot.gov/business/designsupport/stand...
RE: does storm inlet have Q discharge capacity?
I'm guessing that you have an issue with the adequacy of this inlet? If so, more information is needed in order to provide meaningful feedback.
Peter Smart
HydroCAD Software
www.hydrocad.net
RE: does storm inlet have Q discharge capacity?
https://www.fhwa.dot.gov/engineering/hydraulics/pu...
RE: does storm inlet have Q discharge capacity?
Mike McCann, PE, SE (WA)
RE: does storm inlet have Q discharge capacity?
I just need confirmation that the inlet opening can take the Q I'm getting.
RE: does storm inlet have Q discharge capacity?
The inputs are very simple and basic. I just put the width and length of grate and my Q.
But I'm not understanding the output.
If you will look at the output picture, there is water above the grate inlet.
Why would there be water above grate inlet if the inlet was designed for Q?
attached are input and output pic from hydraflow
RE: does storm inlet have Q discharge capacity?
RE: does storm inlet have Q discharge capacity?
RE: does storm inlet have Q discharge capacity?
I run a table of depth/flow. What is the "standard" slope of sag?
I think I can play with this number because I'm re-grading the site but want to use "standard" practice.
RE: does storm inlet have Q discharge capacity?
https://www.codot.gov/business/designsupport/stand...
RE: does storm inlet have Q discharge capacity?
RE: does storm inlet have Q discharge capacity?
Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com
RE: does storm inlet have Q discharge capacity?
RE: does storm inlet have Q discharge capacity?
Read CVG's link to HEC-22. It's comprehensive, and will explain to you step by step what the software is doing. The Hydraflow overlay in Civil-3D basically just automates that PDF.
Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com
RE: does storm inlet have Q discharge capacity?
RE: does storm inlet have Q discharge capacity?
RE: does storm inlet have Q discharge capacity?
RE: does storm inlet have Q discharge capacity?
RE: does storm inlet have Q discharge capacity?
http://www.nfco.com/municipal/resources/weir-orifi...
RE: does storm inlet have Q discharge capacity?
can you link me to inlet volume capacity (LxWxH) design.
Not the inlet grate opening which i have already calculated using hydraflow.
I can also calculate the pipe culvert diameter.
Unfortunately, civil 3d hydraflow does not calculate the inlet volume/area.
I have not looked into civil 3d storm sewer design.
Do I even need to calculate it. I think the volume/area of inlet is bigger than the volume/area of pipe culvert outfall?
RE: does storm inlet have Q discharge capacity?
RE: does storm inlet have Q discharge capacity?
Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com
RE: does storm inlet have Q discharge capacity?
a typical storm drain inlet structure has a volume of maybe 30 or 40 cubic feet (up to the top of the pipe) and at 2 cfs, that would be completely full in say 15 seconds at peak flow. Once it is full, there is no attenuation of flow. Some software such as stormnet and SWMM do allow you to enter volume of inlets and manholes. But frankly, it is a waste of time for analysis of peak storm flow.
If you really want to get crazy, than calculate the storage capacity of your pipes as well and include that in your routing also.
RE: does storm inlet have Q discharge capacity?
You need to correctly fill out the input for hydraflow (not done in your screen capture). You should be able to use Hec-22 that cvg linked previously for a reference.
RE: does storm inlet have Q discharge capacity?
How much Q discharge do you need? How are you figuring it?
What is the maximum depth of flooding that is acceptable?
Take that depth, and use it to drive the Q through the opening with the orifice equation. Then halve it (blockage). There's how much Q that inlet can take before you start to flood.
For instance, assuming those openings are (WAG) 1"x6" (times 40 openings) with 1' of head... drumroll... the Q discharge that inlet has is 8 cfs. Woops! It's clogged, use 4 cfs.
RE: does storm inlet have Q discharge capacity?
I normally use Hydrualic Toolbox.
Now, when you have a Q and want to see if your Inlet can handle it, just enter the maximum allowable ponding depth (Head) at the inlet and determine the Q(inlet). If the Q(inlet) is greater than your Q from drainage area, you are ok. If not, resize the inlet opening. Just like Spartan5 suggested, I would follow that method.
RE: does storm inlet have Q discharge capacity?
KARMA