Ann: Investor Presentation - May 2019, page-80

Dont let the full details of the pond sizes get in the way of the truth.
Annual rainfall at Rincon is something like 5mm, if I remember correctly.
Regarding Sal de Vida, its about 75mm.
"Based on the data from the weather station located in El Fenix Camp (Conhidro, 2001), the mean annual precipitation in the area is 77.4 mm for the period between 1992 and 2001. The main rainy season is between the months of December to March, when 82% of the annual rainfall occurs. The period between April and November is typically dry".
Old data but maybe still relevent.

So yeh you will need more and shallower ponds for those conditions.