Editing a pipe network may cause the hydraulic property data to become invalid.
It is important to note that if you choose to edit a pipe network’s physical properties after if has been imported from an .stm file, the hydraulic information can become invalid. To notify you of this possibility, a warning message similar to the following is displayed whenever you edit pipe network parts from a pipe network that has been imported from the Storm Sewers Extension:
A pipe network containing hydraulic properties has been altered and the properties may be invalid.
This message is displayed only the first time you try to edit the pipe network. If you try to edit the pipe network again, the message is not displayed.
If you do see this message, you may want to use the Edit in Storm Sewers command to export pipe network data and update hydraulic properties. As a minimum, it is recommended that you verify that the hydraulic information for the pipe network is still valid, and has not changed in such as way as to cause undesireable or unexpected results in your design.
If you are editing a pipe network that does not contain values for hydraulic properties, this message is not displayed.