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Water Stewardship Division

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The Role and Importance of Riparian Areas in Manitoba

What Are Riparian Areas?

Riparian areas are the transitional zones that are found along our streambanks, lake shores and wetlands. Often described as "wetter than dry", but "drier than wet" these areas develop unique plant communities. Healthy riparian areas may have any combination of trees, shrubs, grasses, depending on the local conditions. They produce vegetation that is more lush than the surrounding dry land because of better soils and water availability. Healthy riparian areas have many important functions in our watersheds.

Roles of Riparian Areas:

When it comes to water quality, riparian areas are the last line of defense for water that's running off the land into our lakes and streams. They are also extremely important for wildlife. Healthy riparian areas have a number of important functions:

Trap sediment: Riparian areas slow the flow of water, helping to ensure that sediments settle out before they reach the water course.

Filter and buffer water: In addition to removing sediments, riparian vegetation can also trap nutrients and microscopic pathogens that are present in runoff. Studies have shown that a high percentage of pathogens and pollution-causing nutrients in runoff water can be removed by healthy riparian "buffer zones."

Build and maintain streambanks: by trapping sediments and anchoring soils with their extensive root systems, plant communities help ensure that streambanks do not erode excessively.

Store floodwater and energy: Flooded riparian areas act like a safety valve in the watershed because they slow water flows, reduce the size of a flood further downstream and the destructive power of fast-flowing water. When water speed doubles, its ability to erode increases four times and its ability to carry sediments increases sixty-four times.

Recharge groundwater: Riparian areas can help to maintain local water tables.

Maintain biological diversity: In the prairie landscape it has been estimated that riparian areas, which make up less than five percent of the land area, hold the majority of the remaining biological diversity. In some regions, riparian areas are the only remaining natural areas.

Create Primary Productivity: Riparian area vegetation can be harvested in a sustainable manner to provide products such as forage for livestock or high-value hardwood lumber.

What is a Healthy Riparian Area?

Simply put, it is a riparian area that carries out the ecological functions described above. In a healthy riparian area there is vigorous growth trees, shrubs or grasses, stream banks are not eroding beyond what would be considered a normal amount, disturbance by humans or livestock is not excessive, and the watercourse can spill water into the riparian vegetation during a normal flood event.

Some of the key signs that point to the loss of riparian area health include the loss of natural vegetation (quantity, numbers of species and width of the riparian zone) and excessive erosion of the streambanks.

Given that riparian areas are crucial to the health of our surface waters and they are often our only remaining natural areas in some regions, it is especially important that appropriate land use practices are used to maintain or enhance their functions and values.

Useful links:

  • Website of the Manitoba Riparian Health Council
  • Website of The Manitoba Habitat Heritage Corporation includes discussion of riparian program opportunities
  • WetKit for Agriculture: tools for wetland and riparian management
  • Website of the Alberta Cows and Fish Program, an excellent source of riparian information for agricultural producers.