Don't forget, too, how much water people use which goes into the sewage and eventually the river system. Used to be folks bathed once a week (my grandmother was one of 15 and the children used the same bathwater, starting with the youngest!) The washing was boiled up in a copper, which had to be filled by hand, emptied by hand then refilled by hand for rinsing. Now we have folks staying in the farm holiday cottage who complain when the hot water tank runs cold - it's twice the normal domestic size and it always turns out they were in the shower for 20 minute (I could bathe an elephant in less time than that). Washing up was done in one bowl of water - no idea how much a dishwasher uses - our water goes into a Bioplus system which doesn't work with dishwasher salt so we still clean dishes the old-fashioned way.