Cumulative Flow

I wonder if it is possible to display some sort of cumulative flow?

I have in OpenFOAM the field alpha.water which indicates the presence of water in a domain and is a scalar between 0 and 1.
This water flows in a channel.
Is there a way to display all the places at once, where alpha.water was = 1 during all the saved timesteps?

If you select the domain you want you can then use dedicated filters to compute the sum or a programmable filter.

Is that what you want ?