Head (hydrology)

A head is like the start of a river. It is the very beginning of the flow of water in a particular area. Think of it like a bathtub when you first turn on the faucet. Before the water starts to fill up the tub, there is a little piece where the water first comes out. That is like the head of the river.

In hydrology, the head is the highest point in a river or stream. This is where the water begins to flow downhill. It can be a pond, lake, spring, or even a big rock where the water starts to run off. From there, the water starts to move downhill, following the path of the land until it reaches a larger body of water like a lake or an ocean.

The head is really important because it determines a lot about the water that flows downstream. If there is pollution or debris at the head, it can affect everything else down the line. That's why people study the head so they can understand how to keep our water clean and healthy for everyone and everything that needs it.