What Is a Watershed?
A watershed, also known as a drainage basin or catchment area, is an area of land where all precipitation that falls on it, such as rain or snowmelt, drains or flows to a common outlet. This outlet could be a larger river, a lake, an estuary, or an ocean.
Section 2: Key Components of a Watershed
Every watershed is defined by its boundary, called a drainage divide. This is typically a line of high elevation, like a ridge, hill, or mountain range. Gravity causes all the water on one side of the divide to flow into one watershed, while water on the other side flows into a neighboring one.
Section 3: A Practical Example
Imagine a large bowl placed outdoors in the rain. The rim of the bowl acts as the drainage divide. Any raindrop that falls inside the bowl will collect at the bottom. The inside of the bowl is the watershed. On a larger scale, the Mississippi River watershed collects water from 32 U.S. states and drains it into the Gulf of Mexico.
Section 4: Why Are Watersheds Important?
Understanding watersheds is vital for managing water quality and quantity. Activities in one part of the watershed, such as agriculture or urban development, can introduce pollutants that affect the entire downstream water system. Therefore, watershed management is essential for protecting drinking water, supporting ecosystems, and preventing floods.