By Autodesk Technologist for ICM/SWMMSubject: InfoSWMM and H2Map SWMM Selection Set and Domain Manager
You can use the Domain to easily make selection sets using these two steps. You make a Domain which is the areas of the network you are interested in at the current time and then save your Domain of Interest in a Selection Set.
Step 1: Go to Domain Manager and use Map Selection, Query or the Network to make a domain
Step 2. Go to Selection Sets in the Operation Tab of the Attribute Browser and make a New Set and load the domain into your set.
via Blogger http://www.swmm5.net/2013/08/infoswmm-and-h2map-swmm-selection-set.html