catch basin design 2

[pdavlovv]

i need help please. i need to know if there is a sprecific design procedure for sizing catch pits/catch basins to get the appropriate dimmensions.thanks.

 

[beej67]

http://www.fhwa.dot.gov/engineering/hydraulics/pubs/10009/index.cfm

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -

http://www.campbellcivil.com

 

[gbam]

Design Criteria should be set by your local agency. If they do not have criteria identified then you can default to the lext level up similar to this:

City
County
State
Federal

 

[MiketheEngineer]

Your local DNR might be helpful or the county officials as noted above.

 

[pdavlovv]

The CATCHPIT/BASIN I HAVE IS DRAINING FROM LAND E.G PARK LAND NOT FRM ROAD SIDE KERBS/CUBRS. IF I HAVE THE FLOW HW DO I SIZE THE CATCHPIT. ALSO THIS CATCHPIT IS LINKED TO AN UNDERGROUND STORMWATER PIPE NETWORK ALREADY. see attached standard detail to get the idea.

 

[cvg]

first size the inlet to capture the flow
second set basin v depth to account for inlet loss into the storm drain. you will need the hgl of the storm drian main pipe

if the inlet is grated, make sure to account for clogging

 

[beej67]

Download the link I gave you above.

Read it. Take your time and understand it. You can skip the stuff about gutter flow and gutter spread for this particular question, but not the stuff about the grates.

Find your grate in the link, or the closest approximate.

Consider it a 'sag inlet.'

Assume a clogging ratio that is conservative for your application.

Calculate the head over the grate necessary to push the flow through the grate. Make a note of this head.

Now calculate the HGL in the pipe network, using modified rational method or something similar. Make a note of that elevation.

Compare the two. The depth of the "catch pit" as you say must be large enough to handle the worst of those two conditions.



Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -

http://www.campbellcivil.com

 

[brandonbw]

beej67: Nice link and explanation.

Also don't forget to contact the manufacturer for the minimum depths of the devices.

B+W Engineering and Design
Los Angeles Civil and Structural Engineering

http://bwengr.com

 

[pdavlovv]

thank you very much guys