Codestin Geography | River Systems and Watersheds
A river system comprises a main river along with all its tributaries and streams that flow into it, forming a network that drains a specific area of land. This entire land area is known as a watershed or drainage basin. Essentially, a watershed encompasses all the land where precipitation collects and drains into a common outlet, such as a river, lake, or ocean. USGS+2Milwaukee Riverkeeper+2USGS+2USGS+3Education | National Geographic Society+3USGS+3USGS+1Fiveable+1
The boundaries of a watershed are defined by natural land formations like ridges or hills. Rainfall or snowmelt within these boundaries flows downhill, converging into streams and rivers, eventually reaching larger water bodies. Watersheds can vary greatly in size; they may be as small as a few square meters for a tiny creek or span millions of square kilometers, such as the Mississippi River watershed, which drains over three million square kilometers across multiple U.S. states. National Ocean Service+1Education | National Geographic Society+1Education | National Geographic Society
River systems and their watersheds play a crucial role in the environment by transporting water, nutrients, and sediments. They support diverse ecosystems, provide habitats for numerous species, and are vital for human activities including agriculture, industry, and recreation. However, these systems face threats from pollution, overuse, and habitat destruction, which can disrupt their ecological balance and reduce the services they provide. CT.gov
For a visual explanation of watersheds, you might find the following video helpful: