Hi users,
I'm a bit confused regarding what to specify for the elevation of junction's invert.
Should the junction invert be equal to the invert of the 'lowest' connecting pipe?
Kind Regards,
Matt.
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Replies
Data errors happen a lot in model data. I would assume either the node depth is wrong or the invert of the incoming pipe is wrong. Internally this does not matter to SWMM 5 as when you solve the network the engine will raise the rim elevation of the node to a bit above the Soffit or crown of the incoming pipes so the depth will be adjusted for you. I would be more concerned about the invert of the incoming pipe - that does not get adjusted internally and will stay at 1+ meters.
Nice pit and pipe Image! Yes , that is okay - the program uses 1.2 square meters as the default surface area of the node when the water level in the node is below the lowest connecting invert.
Thanks Bob. I've got another question if you do not mind.
For the current stormwater drainage plan I'm looking at, the depth to invert for a particular pit is 0.84 m. The invert of the pit is 222.76 m. I've got listed that the invert of
the pipe connected to the pit is 223.793. So the pipe offset would be 223.793 - 222.76 which is equal to 1.033 m!!
To me this doesn't sound right, the offset cannot be greater than the depth to invert for the pit??? Any thoughts would be appreciated. Cheers, Matt.
It does not have to be but normally it is the lowest connecting link invert. You can have a node invert or a gap between the bottom of the node and the lowest connecting conduit, however,
http://swmm2000.com/forum/topics/what-node-and-link-invert-elevatio...
Hi Bob,
Thanks for your prompt reply and thanks for the welcome. Thanks for that advice, I think it makes sense. Just to clarify, would it be perfectly OK to model a pit such as that shown in the attached picture?
Thanks,
Matt.