OK, well I'm typing this in a McDonalds somewhere in North Yorkshire on my way to a meeting.  Not everyone's favorite place I know, but for the purposes of this challenge I was at least gratified to note that in the Gents they have waterless urinals!

Meanwhile, less good news on the water consumption research.  Seems like a gravity shower uses 35 litres and whilst I might dispute this in my case given that as a typical bloke I take a fairly quick one each day, I note that a power shower uses 80!  So I'll live with the 35 number, x7 = 245 litres.  Definitely no baths for me at 80 a pop.  Unfortunately no (waterless or otherwise) urinals at our place but they reckon 8 litres per toilet flush.  I'm an adherent of the nasty old adage ("if it's brown flush it down; if it's yellow let it mellow") at least for this week, but without getting any more graphic let's just say I should allow about 100 litres for the week.  Tea and coffee - at least 20 litres a week.

Can anyone suggest other water usage please?  I'll keep thinking too, but so far I'm already staring at 360 litres, ie 18 buckets of water, ie 36km to walk (imagining I'm in a developing country and having to go collect each bucket from 2km away).  That's pretty scary, especially as I only walked 6km so far and I have a busy week involving a lot of driving and not much time for walking.  But if I was in that distant community I'd have no debate - water would come first no matter what.