Rivers are the lifeblood of so many cities and civilisations. A great many of the largest cities on earth grew around rivers. For example, London sprouted up around the River Thames. The original Dutch settlers to found New Amsterdam (later New York) knew how important the Hudson River would be to their settlement’s long-term survival. The River Nile is famous throughout history for how it has sustained Egyptian civilisation. There’s so much that rivers give us, but what makes a river a river, as opposed to a stream or brook?

According to The Wiley Online Library, in the United States a stream is defined as a flow of water with a width no greater than 15 metres. A stream becomes a river when the width goes beyond 15 metres. In essence then, some of the greatest rivers in the world begin life as humble streams. From small beginnings, great things can grow.

This brings me back to the River Thames, which is said to originate at Thames Head, near the village of Coates in the Cotswolds.

The above image serves to show how the origins of a river can be, um, fluid. Here, the Thames origin point has dried up, and the limestone filters that provide the Thames’ fresh water supply bring up the water further along the river’s route. It’s no wonder the origin point is often a subject of dispute! At this stage, the Thames is far from being the roaring river that it’s so well known as, but like I said, all great things must start somewhere.

There’s a lesson there.