A more thorough explanation:

A natural watercourse is a body of water that flows in a defined channel with banks and a bed. This can include rivers, creeks, springs, lakes, and marshes that have flowing streams. It does not include surface water that flows intermittently and in an indefinite channel.

For example, a river that flows through a valley with banks and a bed is a natural watercourse. However, a temporary stream that only flows during heavy rain and does not have a defined channel is not a natural watercourse.

It is important to note that an artificial watercourse, such as a man-made canal, may be considered a natural watercourse if it has been maintained for a sufficient length of time and has the characteristics of a natural watercourse.

Overall, a natural watercourse is a significant feature in water law as it determines the rights and regulations for water use and appropriation.