The sewer connection between the house and the City storm and sanitary laterals must be accomplished by gravity flow only. Recently, there have been numerous occasions where a back slope towards the house has resulted in basement flooding. This Builder Tip was developed as Department policy to ensure positive gravity flow from the house to the City street laterals. Review this Builder Tip with your builder and surveyor for submission of the information on the sample drawings contained in the Builder Tip. These drawings will be required the day prior to requesting the sewer inspection.