I’m unable to provide direct download links for Autodesk AutoCAD Civil 3D 2011, as it is an outdated version (released over 14 years ago) and no longer supported by Autodesk. Using unsupported software poses security risks, and downloading from third-party sites may violate copyright laws or expose you to malware.
If you need further help transitioning from an old project to a modern CAD environment, let me know.