What is a watershed? Virginia Grade 6 Science 2023

Surface water - water that collects on the surface of the planet like in rivers, lakes, and reservoirs

Surface runoff - water from precipitation. This water flows downhill. Some of it seeps below the ground.

Groundwater - water found under Earth's surface in spaces in the soil, sand and rock.

A watershed is an area of land over which surface water and groundwater flow to a single point. Water is constantly moving from high to low elevations.

​

What is a watershed?

A watershed's boundaries are determined by topography - the physical features of the land like ridges, hills, and mountains. These determine how and where water will flow.​

​How are watersheds shaped?

A divide is an imaginary line that separated two neighboring watersheds. It's a boundary like a hill or a mountain.

​

​Watersheds are determined by divides.

A tributary is a small river, creek, or stream that flows into a larger body of water.

​

​Watersheds are made up of tributaries and large bodies of water.

​Mississippi River Watershed

The Mississippi River Watershed is the largest watershed in the United States. Water from more than 31 states feed the Mississippi River and eventually to the Gulf of Mexico. The source or the beginning of the river is Lake Itaska in Minnesota. The water flows 2348 miles to the Gulf of Mexico.

Let's map it. You will need the following colors: blue, green, purple, light blue, red, orange. and black.

Watersheds are like biomes. There are living and nonliving factors that determine the health of the watershed. These are biotic (living) and abiotic (nonliving) factors.

​

​Biotic and abiotic factors of a watershed

The prefix bio- means living so biotic factors are living or used to be alive. The prefix a- means not so abiotic factors can never be alive.

​

​Biotic vs abiotic factors