All dear.
Me Stephanie,
I would like to know the formula used in the tutorial on the page 32 of the French version or the page 33 of the English version; to have the result of consumption rate of the agricultural demand(request) equals in 90. Otherwise (differently) say, what is the formula allowing to estimate the reteof consumption? Thank you.

Dear Amedee,

The 90% value used in the tutorial is an example value - it is not based on data. To obtain that information, you would have to have a good sense of how much water agriculture withdraws, and how much water is returned to the river. For example, if I had 100 MCM coming in, and 15 MCM returning to the river:

15/100 = 15% return, so 85% consumption. But it would be based on data, or in the absence of that, estimations and assumptions.