Autodesk Storm and Sanitary Analysis is a Civil 3d 2011 Subscription benefit. It requires that either AutoCAD Civil 3d 2011 or Map 3d 2011 be installed and it is a Stand-alone product that requires you to leave Civil 3d to launch. If you want to launch SSA from Civil 3d, add the SSA program path to the Working Path of your current profile, and add a command macro button on your Ribbon that uses the following command macro;
For example; for Windows XP, add the following path;
C:\Program Files\Autodesk\SSA Stand-alone 2011\
The path for Win7 64 is; (SSA is a 32-bit product)
C:\Program Files (x86)\Autodesk\SSA Stand-alone 2011\
Note: This works in Civil 3d 2010 as long as you meet the installation requirements of SSA. SSA can read and write the Hydraflow STM file format to allow you to use 2010. There are other reasons why you may want to push 2011 out to your corporation.