Don't see what your point is. Look at the catchment around Canberra compared to Perth. Fact is we have very little runoff in to WA dams these days. Rainfall drops off quite dramatically in WA as you move away from the coast. I Farmed in WA for 35 years and there is no doubt we have had a drying trend since the seventies. What has caused it? Well of that I couldn't say.
