Low-impact living: Last week I wrote about toilet paper. Today I'm staying in that most important place, the bathroom, to discuss another precious resource. Next time you flush the toilet, think about this: the six to nine litres that you just sluiced away represent the entire daily usage of a person in Mali, Somalia, Mozambique or Uganda.
And it's twice that of the average Gambian. Add a couple of extra litres for hand-washing, and you've gone through more than a citizen of Tanzania uses in a day.
I hesitate to advocate not flushing, but braver souls might wish to adopt the maxim of some water conservationists: "If it's yellow, let it mellow. If it's brown, flush it down." Such a policy certainly lowers water usage dramatically, but it's also a sure way of raising anxiety levels in reluctant participants and guests. This is a practice that is probably best suited to close-knit households where everyone is in agreement.
All this toilet talk isn't just to point out that we should be saving water (which we should, because our consumption has increased to a level that may be unsustainable), but mainly because I want to stress just how lucky we are.
Irish people use about 150 litres of domestic water a day (and if you have a power shower, you can add another 100 or so). That water is clean, drinkable and delivered directly to our houses: pull a lever, push a button or turn a tap, and out it pours. Compare that with many parts of rural Africa, where the average usage is less than 10 litres per person. Where water is scarce, women, and sometimes children, travel miles by foot to a source (water-hauling is not considered a man's work). There they may queue for hours before journeying home again with their few precious litres.
The business of getting water - and never enough of it - may take the best part of the day, and is so all-consuming that children never get to school, and women have little time to care for their families, let alone work.
The World Health Organisation estimates that African women and children spend up to 40 billion hours a year collecting water. This hard-won water is often contaminated and unsafe to drink. You can learn all about it from WaterAid (www.wateraid.org) - and make a difference by making a donation.
So, next time you flush, be happy for reservoirs, wells and pipes, and that you didn't have to carry the water on your head, from several kilometres away.