Manholes- Structure Junction/Sewer Device, or both?

[TSmith]

Good evening. 

I am curious if manhole feature classes should be mapped to the Structure Junction FC, the Sewer Device FC, or both. I know the ESRI AP ships with an attribute rule that creates a manhole channel (device) at the location of each new manhole (structure junction) on insert. However, during the data loading process, I don't believe that rule was executed. It took quite a bit of time to copy every structure junction into the sewer device feature class, and then wait for that rule to execute for over 6000 manholes. 

So, my question is: what is the best practice for the UN Wastewater Model? Should Manholes only be mapped to Structure Junction? Is it best practice to load certain attributes from manholes into Sewer Device, and other attributes (pertaining to the cover itself) into the structure FC? I have worked with some clients that prefer the connectivity without the association, and others do not care one way or the other. 

Just curious how you guys have been approaching this. It has been difficult finding good documentation for this. 

Thanks!

[Anonymous User · Accepted solution]

I start by adding the manhole (structure junction) and this automatically places a manhole channel (sewer device) in the same location. I have had no issues with this. I don't know that you can have just the structure junction without the device. It is my understanding you would not be able to run traces. 

Something I like about the manhole (structure junction) is that when you place it first and then snap the sewer line to it, it creates a pipe connection and connects via association. This allows you to have a separate elevation for your sewer and for where the pipe enters the vault. This is good because sometimes your downstream rim elevation is higher than your upstream, but the underground is actually lower as it would need to be for gravity pipes. Also, you may have 2, 3, or 4 pipes connecting to one manhole and this lets you capture each invert elevation.

[TSmith]

Does this automatically happen during data load? Or only on creation of a new manhole (structure junction) 

[AlexKabak]

In addition to the Line - Snap to Manhole attribute rule (this is the attribute rule that runs when a main is snapped to the manhole channel) and the Create Manhole Channel attribute rule (this is the attribute rule that creates manhole channels when a manhole is added) there are accompanying batch attribute rules of the same name (see images below). The batch attribute rules allow the user to run the rule at their own time, rather then immediately when the action takes place.

For example, you can load you manholes and pipes normally. Once loaded, run the Create Manhole Channel batch attribute rule. This will add the Manhole Channels at all Manhole locations. Next run the Line - Snap to Manhole batch attribute rule and it will execute the rule, splitting the line, adding the pipe connections, and associating the pipe connections to the manhole. See the link below for running Batch Attribute Rules.

https://pro.arcgis.com/en/pro-app/2.8/help/data/geodatabases/overview/calculation-attribute-rules.ht...

[RobertKrisher]

For performance reasons attribute rules typically don't run during data load, only during the creation of a new manhole structure.  If you want to have a manhole device and structure at the same location this is something you can manage using your data conversion process (Esri Data Loading Tools, Data Interoperability Extension, or raw python).