Grunt makes it very convenient to create waterfall charts. We start by inserting a waterfall from the Grunt tab.
All series in the chart are stacked, and inserting another series will add to this stack.
If you specify a capital "S" in your data, Grunt will calculate your totals. The capital "S" will summarize across all series. If you want to visualize a split total, you can repeat a lowercase "s" for all series. In this case, the lowercase "s" sums across a single series.
If you have values that are highly uncertain, you can drag them above the waterline. You do that by clicking on the connectors - and dragging the waterline indicator to the correct position. Note that the series above the waterline will not be included in your sum, so you would add the sum directly into your data if you want it displayed.
To improve the visual appearance, you can add a forecast rule to these series to indicate that they differ from the rest.
You can add more staples by inserting additional columns into your data. This way, you can build quite sophisticated bridges.
Waterfall charts also support auxiliaries such as value jumps, and you can insert them from the main menu.