Rivers are the wondrous sculptors of the elaborate landscapes found on planet earth. They wear away mighty mountains, scour rock faces, carve deep valleys, create fertile plains, and then decorate them with their meanderings.

‘For eons, running water obeyed only its own laws. To be truly alive, a river must be wild: wilful and unhindered. Yearning for the ocean, its only purpose is to descend.'

In many places, rivers are seen as a source of great hope and something to be worshipped. In others they are where people are healed and blessed, where sins are washed away and the dead purified.

Rivers are the arteries of the planet. Wherever they travel life, forms can emerge, survive and flourish, including human life. The will of rivers determined our early destiny. They were the transport routes that enabled and nourished the spread of human beings, and that created the boundaries between regions and countries. Just as rivers shaped the landscape, they have also shaped human existence.

‘Today, the world's greatest cities all have a river at their heart.'

Rivers are fundamental to human existence but are indifferent to human plans and dreams. In flood, they can wreak havoc, and in drought, they can disappear. And so, extraordinary means have been devised to control them and harness their force.

‘Today, there is scarcely a river unspanned, undammed or undiverted.'

The cost is high in some cases. The greatest dams provide power and prosperity, slake the thirst of millions and allow deserts to bloom all year, but when trapped and static, the water stagnates, and its sediment falls to the dam floor where it is inaccessible to those who depend on the fertility it would otherwise have delivered.

‘For all their might though, rivers are fragile: easily harmed and not so easily mended. Time and again, upstream need and upstream greed have led to downstream disaster.'

The use of poisons and plastics, and the sheer size of the human population, means that many rivers are living precariously or even fighting for survival. With humanity sharing its fate with rivers, the wash-up will determine the destinies of future generations.

‘We must ask ourselves: Are we being good ancestors?'

All is not lost – yet. Rivers are irrepressible, and given the chance, possess miraculous powers of recovery. Also, the cycle of renewal continues. Upon vanishing into oceans, the heat from the sun draws rivers up into the atmosphere, ready to fall back to earth reincarnated.