What is a Watershed?

What is a Watershed?


Watersheds near Nanaimo

A watershed is an area of land that catches rain and snow and where water flows downward into a specific river, stream, lake, or aquifer.

All land is part of a watershed and we all live in a watershed.

Think about your local creek, river, or stream.

  • Where does it come from?
  • What type of landscapes does it pass through?
  • Where does the water in your backyard go?

All of the area covered is a watershed.

What is Groundwater?  What is Surface Water?

When rain falls on the ground, some of it travels slowly down through the ground to the aquifer. As water makes its slow journey, it is filtered by soil, sand and gravel. This water is called groundwater.

Some of the rainwater runs over the land into lakes, rivers, and streams. This water is called surface water.

How Wetlands Work


How Riparian Areas Work


Interactions between Groundwater & Surface Water

Groundwater and surface water are connected. Have you ever wondered how rivers continue to flow even if there has been no rain for weeks? One answer is groundwater. It continues to supply water through the banks and beds of rivers and streams. Once in the river, groundwater becomes surface water! And sometimes surface water goes back into the ground.  Learn more about Aquifers.

What is Watershed Stress?

Much like a bank account, if more water is leaving than is coming in, the supply will be depleted. A level of reserve is included in the balance. The water use is sustainable when supply and demand are in balance. When demand outstrips supply, a watershed can experience stress.

Learn more about