What is a Watershed

Watershed Defined:

a watershed is the land area that drains water to a particular stream, river, estuary or bay. It is a land feature that can be identified by tracing a line along the highest elevations between two areas on a map.

Not only does water run into the streams and rivers from the surface of the watershed, but water also filters through the soil, and some of this water eventually drains into the same streams and rivers

Watershed Diagram

The diagram below suggests a typical watershed that starts with small head-water streams in the higher elevations of the drainage basin. Water flows downhill from the drainage divide into larger streams, eventually joining a river. As more tributary streams join the river, the volume of water increases. This river eventually flows downstream into an even larger river at the confluence

A Healthy Watershed

Watersheds direct­ly affect water quality, whether it’s for drinking or recreation.  For example, algae blooms or anoxic events resulting from nutrient rich runoff draining into waterway, harm watershed health, as do pesticides and contaminants.  PEI is dependant on its ground water supplies so extreme care must be taken to protect it.

An Unhealthy Watershed

Watersheds affect wildlife. The polluted water supply that results can become harmful to humans. Aquatic life quickly suffers the effects of watershed pollution while new pollutants introduced into ecosystems alter wildlife habitats. This reduces biodiversity by eliminating some species and introducing new, invasive ones that destroy the native species. That, in turn, can affect the food chain in our watershed, from microbial organisms that feed birds and animals to fish that feed humans.



Components of our Watershed

We are all part of a watershed and dependant on the water that runs through it.

A watershed is the area of land that catches snow and rain and drains it to a larger body of water, such as a marsh, lake, stream. river or estuary. Topography defines the entire watershed, as it shapes the course and speed of water moving through the area.

Watersheds can range in size from a few hectares to thousands of square kilometres.  All watersheds flow from headwaters (the headwaters of the Whetley River Watershed come from Brookfield ) to outlets (the WR empties into Rustico Bay ), eventually ending in the Gulf of St. Lawrence and the Atlantic Ocean.

Watersheds fulfill three primary functions: to capture water, filter and store it in the soil then release it into a water body.

The Wheatley River’s Watersheds are composed of many parts, including, surface water – (estuary, bay, river, creeks, stream’s and wetlands), riparian areas, uplands and groundwater.

Natural water flow in the Wheatley River changes with season. In the spring flow is high as the snow melts. But steams flow can be is reduced to a mere trickle in hot summers when there is little rain.

The Wheatley River has many tributaries that feed into it. (see maps).


A wetland is an area of land that is saturated with water for all or part of the year. A wetland can be a marsh, pond or bog. Wetlands are typically surrounded by riparian vegetation.

Wetlands are like giant sponges. They store water collected during wet periods, reduce flooding, filter out pollutants, diseases and nutrients, and slowly release the water into groundwater andor rivers, streams and creeks during drier periods.  In addition, wetlands provide habitat for wildlife and healthy wetlands naturally attract wildlife.

Riparian Vegetation

The plants that grow along or near the riverbanks, lakes and wetlands are called riparian vegetation. Natural riparian vegetation in the Wheatley River Watershed includes plants such as alder, dogwood, willow, chokecherry and cattails, s well as maple, birch and other tree species. Riparian vegetation is important for a number of reasons:

  1. The roots of riparian plants stabilize stream banks, and prevent erosion and silting-in of streams and river channels.
  2. Spongy soils in riparian areas slow and store water, reducing flooding and later releasing water to aquifers and streams.
  3. The roots and stems of riparian vegetation are filters that absorb and trap nutrients, diseases and pollutants, thereby improving water quality.
  4. Riparian vegetation provides important habitat for aquatic insects, fish and wildlife.


The uplands of our watersheds are areas where there is not usually standing water and would typicly be either forested or agricultural land.


Groundwater is also part of a watershed. Groundwater is all water under the surface of the ground. It is stored in the soil and it can be found far under the ground in deep aquifers (underground water-bearing formations capable of yielding water), or very near the ground surface. Groundwater flows through the soil into our streams, river, estuary and wetlands. Groundwater also rises to the surface in springs.

Groundwater is always naturally in motion. Recharge areas are places where surface water soaks (infiltrates) into the soil to become groundwater. Discharge areas are places where groundwater seeps or flows into surface water (e.g. springs). The Wheatley River and it`s tributaries are fed by many springs along their paths.