This free tool from Autodesk will allow you to quickly collect data from across all your Civil 3D drawing files into a single Excel spreadsheet
The Autodesk Standardized Data Tool for Civil 3D (part of the Autodesk Interoperability Tools) installer can be downloaded from manage.autodesk.com, or installed directly through Autodesk Access (formerly the Autodesk Desktop App).
The Autodesk Standardized Data Tool for Civil 3D is free for licensed Civil 3D users to download and use, just select your Civil 3D version and get started.
These videos will help you understand the features of the Standardized Data Tool and learn how to use them.