Oct 11, 2016 – Autodesk releases an updated Storm Sewers Help file update for AutoCAD Civil 3D 2016 Service Pack 3
Autodesk released AutoCAD Civil 3D 2016 Service Pack 3 in July 2016.
This update adds a new version of the Storm Sewers CHM file.
The update is available from the AutoCAD Civil 3D public download page.
Here’s the link to the Readme.