Explore the Lake Champlain Basin

Land, rivers, streams and lakes work together to process, filter, and help manage rainwater.

But when there are pollutants, erosion, sediment or other materials in rainwater runoff, it creates short and long-term problems in the environment.

What is a Watershed?

Learn about what makes up a watershed and how stormwater runoff affects the stream, rivers, and Lake Champlain.

A watershed is an area of land that drains all the streams and rainfall to a common outlet, such as the outflow of a reservoir, mouth of a bay, or in this case, Lake Champlain. The word watershed is sometimes used interchangeably with drainage basin or catchment.

A watershed is an area of land that drains all the streams and rainfall to a common outlet, such as the outflow of a reservoir, mouth of a bay, or in this case, Lake Champlain. The word watershed is sometimes used interchangeably with drainage basin or catchment.

The watershed consists of surface water—lakes, streams, reservoirs, and wetlands—and all the underlying ground water.

Larger watersheds contain many smaller watersheds. It all depends on the outflow point; all of the land that drains water to the outflow point is the watershed for that outflow location.

There are actually 11 different sub-basin or smaller watersheds that feed into the Lake Champlain watershed. Smaller watersheds can be found on the New York side of Lake Champlain, the Vermont side, and even north into Canada.

Watersheds are often separated by hills, mountains, or other geographic features.

Rain and snow melt are commonly referred to as stormwater. Any stormwater not absorbed by the ground flows into streams and rivers, carrying with it pollutants and dirt picked up along the way.

Over time, streams and rivers carry stormwater to Lake Champlain. The stormwater carried into Lake Champlain brings with it pollutants and dirt.

Water that is absorbed by the ground is often filtered before it reaches groundwater deposits. This groundwater also feeds into the lake underground through percolation, the movement of groundwater in the saturated zone. Water moves slowly by percolation through very small pores along parallel, threadlike paths.

By decreasing the amount of stormwater that flows directly into streams and rivers, you can help reduce the pollutants and dirt in streams, rivers, and Lake Champlain.

Stream Monitoring

As part of our monitoring program, we ask volunteers to monitor “impaired” streams each year. These include streams that are at-risk for pollution or other problems. We test for phosphorus, chloride, and turbidity (how cloudy the water is).

Learn More about Stream Monitoring

Stream Storytelling

In recent years, we asked our volunteers to record their experiences when visiting our monitored streams, including what they saw and how they felt.

Read their thoughts, and see their photos in our Google Earth Project.

For Kids

We’ve included science experiments that are easy to do with your children. The experiments highlight the impact of stormwater runoff and how it can affect the lake.

About Algae Blooms

Cyanobacteria, or blue-green algae, is a photosynthetic bacteria that occurs naturally in waters used for recreation, such as swimming, boating, and waterskiing.

Certain environmental conditions, such as elevated levels of nutrients, warmer temperatures, still water, and sunlight exposure can promote the growth of cyanobacteria to higher densities, forming algae blooms.
Learn more about algae blooms and what you can do to help prevent them.