I think the main pproblem is from evaporation rather than the plant using it!
I grow my mellons in 12" pots in growbag trays with capillary matting and have to fill them up about twice a week in mid summer.
Im thinking of covering the top of the pots with white plastic so the plant can grow through a hole in the middle and also covering the tray with a white plastic sheet to also try and stop evaporation.
I don't see how a plant can use so much water, so as i say i think the water usage is more down to evaporation and covering would be the best bet.
Well this is what i will be doing this year