This tool creates 1D/2D connections at the endpoints of SWMM channels. HX connections are created on the upstream end and SX connections are created on the downstream end. The connections should be reviewed to ensure that they are correctly positioned.

It is recommended to name the output layer with the prefix "2d_bc" so TUFLOW styles can be automatically applied.

If "Set 2D cell elevation to 1D culvert invert at 1D/2D connection cells if needed" is checked, SX and HX boundaries will have the "Flags" attribute set to "Z." This ensures that the valid elevations occur at the 1D/2D interface. HX boundaries require 2D cell elevations at or above the 1D elevation while SX boundaries require 2D cell elevations at or below the 1D elevation.

## Limitations

This tool helps create the HX and SX connections. However, their positions may not be completely accurate and in some instances connections are not wanted. The user will need to correct any errors generated by the tool.