By using the constraint-based design features in SewerCAD, you can automatically design gravity piping and structures. The design is flexible enough to allow you to specify the elements to be designed, from a single pipe size to the entire system, or anything in between, by simply entering your design restrictions: minimum and maximum velocities, covers, slopes, and tractive stress; pipe and manhole matching offsets; and allow (or not) drop structures. SewerCAD will automatically determine cost-effective pipe sizes and invert elevations, avoiding unnecessary pipe trench excavation.