The announcement of the upcoming symposium on Perth's 'lost lakes' - 'a 200 year history of infill, paving, draining, damming, over-building, covering and erasure', set my mind whirring. It made me think of the lost lagoons of my home-town, Palmerston North - once the food-baskets of Rangitane, and of course the buried streams of Christchurch, which reasserted themselves in the Canterbury earthquakes, destabilising the ground they had been buried under, with tragic conseque

I was privileged last month to be invited to be keynote speaker at the Fifth Biennial Symposium of the International Society of River Society, held not far from the mighty Waikato River (pictured). When first approached, I was a little daunted by the prospect: what on earth could I offer to a conference of river experts? I settled on a talk focusing on how our understanding of and attitudes towards rivers have changed through history. From the way the first people to settle i