You may have seen this immortal poem pasted above an environmentally aware toilet, or had it chanted at you by persons of school-going age (they generally find it quite amusing):
If it’s yellow, let it mellow,
if it’s brown, flush it down!
Each time you flush the toilet, you flush away 10-12 litres of high-quality drinking water. If you find the thought of "letting it mellow" distasteful, then flush with "grey" waste water from your washing machine, bath/shower, or from washing your hands after you use the toilet. Another trick is to put a plastic bottle filled with water (and maybe some sand or stones to help weigh it down) in the cistern to reduce the flush volume. And next time you remodel your bathroom, consider installing a low-flow (low-flush) toilet.
(Olivia Rose-Innes, EnviroHealth Editor, September 2011)