There are currently two ways that you can do this.
1) If you are only going to use one contour to define the lateral direction then you may achieve a good result via the User Defined “Polyline” option in the tape block tools. The results of this tool can be heavily influenced by the start point of the polyline, direction, and number of vertices so you may need a few tries to get the results that you require. The best results are achieved if the polyline you draw extends beyond the boundaries of the block. Note that this tool maintains the shape at a constant spacing, which may not be what you require.
2) If the tapes need to be different for the different contour levels then the best way would be to draw out tapes or polylines as required, to follow the contours. If you’ve drawn polylines, select these and convert to tapes.
The IRRICAD Team
IRRICAD Version 19+ includes the Polyline tapes feature in the Irrigation Block dialog.