The dams are full for now – but Sydney will need new water supplies as rainfall becomes less reliable
- Written by Stuart Khan, Professor of Civil & Environmental Engineering, UNSW Sydney

When Australia last went into El Niño, we had water supply issues in Brisbane, Sydney, Canberra and Melbourne.
Are we better placed now, after three wet La Niña years? Yes and no. Take Sydney as an example. After the big wet, Greater Sydney’s dams are around 90% full, holding more than four times the volume we use in...