Keeping mind my touring is in Western Australia so even in winter (more our touring season in the southern half) water is a problem. I have carried up to 35 litres but on my latest little sojourn I had to carry water for three days at a time. As this was on my fatbike, my Salsa Mukluk I had to add a rack to the bike to use as a base for the additional water.
This is my setup for the ride. You can see the rack, a
Salsa Alternator 170 which is rated for 15 kg. On the top of the rack is an
Ortlieb Water Bag which holds 10 litres.
On the down tube I have another 1.5 litres and inside the frame bag I had a 1.5 litre Evernew bladder and another 1.5 soda bottle. The balance was meant to be in a one litre Zefal water bottle on the top-tube but I left it at home by mistake so resorted to a 750 ml bottle that I purchased locally.
The water bag carried pretty well (I did have to do a bit of adjusting most days to get it right) but then I was riding rough 4WD tracks and beaches a lot of the time. On the road sections it carried well.
For curiosity sake this is my setup with the
Surly Long Haul Trucker and
Extrawheel Voyager trailer for carrying a max of 35 litres and 20 days food.