The Niagara Escarpment contains the headwaters of five major river systems: the Nottawasaga, Credit, Humber, Saugeen, and Grand Rivers. The Niagara River crosses the Escarpment through the famous Niagara Falls and Niagara Gorge. There are also smaller rivers such as the Pottawatomi and Noisy rivers, as well as many streams.
Streams and rivers are important freshwater links through the Escarpment. They are home to a variety of fish, plants, animals, and insects. Hike along the Escarpment and you might see trout, crayfish, freshwater shrimp, water lilies, and snapping turtles in the streams you encounter.
Rivers and streams have obvious importance for fish. For example, the Noisy River is a small headwater tributary of the Nottawasaga watershed. It is a very clean, clear river and has been noted as an important cold water fishery, containing both brook trout and rainbow trout populations. Other fish present in the Noisy River include several species of dace and minnow.
As well as their direct importance for fish habitat, streams can also be used as indicators of the health of an ecosystem. Streams that have clean water, a range of plants on the banks, meandering routes and plenty of aquatic invertebrates can be thought of as healthy streams, and generally indicate that the surrounding ecosystems are in good condition.
Riparian areas are really important to stream quality. A riparian buffer is the vegetated area immediately adjacent to the stream bank, that forms a transition zone between the watercourse and the surrounding land use. Riparian buffers are perhaps the most effective form of protection for rivers and streams. Riparian vegetation protects the stream banks from erosion and plays a role in regulating the water temperature. It also filters pollutants such as pesticides and prevents them from entering the river, which helps to maintain good water quality.
Riparian areas contain their own biodiversity, which often interacts with the stream’s biodiversity. The plant community in the riparian zone is made up of water-loving grasses, shrubs and trees, and provides great habitat for wildlife. Birds such as the belted kingfisher can be seen nesting in riparian areas on the Escarpment, feeding on insects that emerge from the water.
Unfortunately, rivers and streams are sensitive to human impacts and not all Escarpment streams are in the best condition. Land clearing such as for agriculture, urban development, roads etc. can have a negative effect on water quality and quantity, particularly when the riparian buffer is reduced or lost. These factors can cause increased run-off and sediment loading, which have negative consequences including increased levels of contaminants entering the water, increased water temperature, and depletion of oxygen. This can make the river uninhabitable for some native species and result in reduced biodiversity.
Stream rehabilitation activities can help to restore degraded streams to a healthier state. The first step in stream rehabilitation is typically to restore the riparian buffers in order to stabilize the stream banks. This involves planting trees and other vegetation along the edge of the stream. On farmland, fencing may be required to keep livestock away from the stream bank. Other activities that can help restore streams include installing structures to trap silt and provide shade for fish.
For example, Ducks Unlimited Canada and Credit Valley Conservation are currently undertaking stream rehabilitation efforts in the Upper Credit River. To help stabilize the banks along a degraded part of the stream, volunteers help to install old christmas trees in the edges of the streams. The christmas trees will trap silt from the river and help to keep the water clean, as well as provide a stable bank that riparian vegetation can grow on.
If want help rehabilitating a stream on your property, contact your local Conservation Authority – they can often help out with activities such as planting riparian buffers, dam removal or modification, fish habitat rehabilitation, and natural channel restoration.