The state government has declared the winter total sprinkler ban in Perth and Mandurah a success and has decided to make this a permanent feature. It is obvious that reducing the scheme water used on lawns saves much needed reserves. The trial 2 month ban saved 50 million litres of water. What is not obvious is whether banning bore water use makes any difference at all.
More water is drained from the shallow aquifer in Perth every year by the Water Authority than is drawn by garden bores. This is done to stop the ground water from rising too high. By reducing garden bore use in winter the Water Authority will just have to drain more water out of the aquifer. Where is the common sense in that. Further more during the trial 362 educational letters and 1160 warnings were issued to bore owners with the threat of fines if they persist.
Environmentally the use of garden bores are helpful because they replace the function of vegetation that used to draw the water to the surface. Many of the trees in the metro area have been removed to build houses. A further problem with banning garden bores is that many of the older bores if not run for a while need priming. This doesn’t sound like a big problem but many of the wells are over 2 metres deep and represent a real safety risk.
So why are we banning garden bores if it makes no difference to the scheme dam levels, it is environmentally disadvantageous, and causes mechanical problems which is a real safety risk to fix. The water authority would not reply to me when questioned about this. I believe the real reason is so it is easier to stop and control users of the scheme water.