Flood Modelling using SewerGEMS

Question

I am trying to build a city drainage network and I want to understand the extent of flooding in the problematic areas. How can I do flood modelling using sewerGEMS. Also, if it is not possible in sewerGEMS, is there any other Bentley product that can hep me. I need to the extent of flooding, depth of flooding and the time it takes to clear that out. 
 
 Thanks and Regards 
 Manish

Scott Kampa · Answer

Hello Manish, 
 We may need a few more details related to what you are trying to model. SewerGEMS is able to model runoff from catchments, which would be diverted to structures for a sewer or combined storm-sewer system. Diverse land types can be modeled as catchments, including paved areas. In addition, ponding above elements , such as manholes, can be modeled in SewerGEMS as well. This ponding assumes that the overflow remains near the structure and will re-enter the system once the system is no longer surcharged. 
 If this is not what you are trying to model, I would refer you to your account manager, who may be able to further assist you in helping to identify a product that may be better suited for your purposes. If you are unsure of who your account manager is, please send me a private message with your company name and email address and I will get you in touch with someone. 
 Regards, 
 Scott

Jesse Dringoli · Answer

Manish, 
 
SewerGEMS has the ability to model overflow from manholes and catchments, which can be routed to gutters or channels. You also have the ability to model surface storage, where overflow is essentially constrained within a pond above the manhole/catchbasin rim. 
 
What you describe appears to go beyond the current scope of what SewerGEMS can do. You may want to look into Bentley MX Drainage.

Jesse Dringoli · Answer

Hello Manish, 
 It is best to submit new questions as a new forum thread. 
 Regarding Modelbuilder : if the conduit shape is not set during the Field Mapping step of Modelbuilder, newly imported pipes will take on the properties of the currently active Prototype. By default, the default prototype uses Circular as the shape. So, if your data source has a column with the shape, you can map that during import. Or, you can set up a prototype with the shape set to rectangular / box and make that active before import. You'll need to map the Rise and Span in Modelbuilder though. If you mapped the rise and span but not the shape, you should be able to simply global edit the shape from circular to box after import and the imported rise and span should show up. More on prototypes here: 
 Changing the default property values when creating model 
 Regarding SWMM import : we have seen some other products export SWMM files with non-standard formatting or other issues, causing problems during import into the Bentley product. In these cases, I suggest attempting to open the file in EPSWMM itself, confirm the file integrity, then if OK, re-export to INP format and attempt to import that into SewerGEMS. See related article: 
 Troubleshooting problems with importing EPANET or EPASWMM files 
 If this does not help, please start a new thread and include your model file for further review. 
 There are two options for sharing your model on Communities, whichever you choose please be sure to zip your files first. The first option is to attach the zip file containing your model to your reply on the forum using the Advanced Reply Editor (you'll find the link below and to the right of the reply box). If your data is confidential please use the instructions in the link below to send it via Bentley Sharefile. Files uploaded to Sharefile can only be viewed by Bentley employees. Please be sure to reply on this thread with the name of the file after it has been uploaded. http://communities.bentley.com/help/w/be_communities_help/7079.be-communities-secure-file-upload

Jesse Dringoli · Answer

Hello Manish, 
 The downstream trace feature is located in the Terrain Model tool, found in the View menu. Here's an article with more information: 
 Digital Terrain Models and Downstream Trace