Connecting to Multiple gINT Project Databases in gINT Civil Tools

I have a gINT Civil Tools 3D model, to which I have connected a gINT project database.  I mapped to the Borehole, Lithology, AND Water Levels tables and queried data.  When I try to connect to a second database which contains additional borings, I am unable to complete the connection.  The Database Connectivity and Mapping window prompts me to define the "mandatory field depth in the table Water Levels".  When I try to define the field in the table mapping tab, although the second database contains a Water Levels table, I cannot see the Water Levels table in the pull down list, and therefore I cannot define the field.  I suspect this may be due to the second project database containing no data in the Water Levels table.   Is there a requirement in gINT Civil Tools for data to exist in all tables mapped?