Riparian Zone: The Edge That Gives You An Edge

A riparian zone is the area of vegetation that runs along the bank of a river. Thick vegetation, including shrubs, vines, trees, and grasses, characterize a riparian zone.

Healthy riparian zones are important to a watershed. They help maintain streams and rivers in their natural state.

Thick riparian vegetation acts as a buffer between the land and the water. Chemicals, such as fertilizers and pesticides, which are applied to the land, will run downhill into the river. Riparian plants absorb many of these excess chemicals through their roots. During heavy rains, dense riparian vegetation slows the downhill flow of rainwater into the river. This helps maintain an even water level and current in the river, and helps prevent floods. Dense roots along the river bank help prevent erosion of the river bank.

Thick riparian vegetation also protects upland habitat. Floods are a natural process. After heavy rains water levels rise, and the water flows faster (see Hydrology - Surface Water for more information). Dense vegetation acts like a wall to reduce flood water overflowing onto the land.

Thick plant cover also provides important habitat for many species. Riparian zones offer an ideal site for birds to build nests that are hidden from predators. Small mammals can take shelter in the thick plant cover. Grazing animals, such as deer, find an important source of vegetation to eat year round.

We have destroyed many sections of riparian zone along rivers throughout the United States. Sometimes riparian vegetation is removed for planting crops or raising farm animals. Vegetation is also removed for building homes and industry. Sometimes vegetation is removed to make room for levees. People build mounds of sand and gravel, known as levees, along the banks of a river. Levees act like a wall to prevent floods when the river is high. The good thing about levees is that they prevent large floods and allow people to live and farm throughout the entire floodplain (area of level land on either side of a river, prone to being flooded). A problem with levees is that they prevent small, regular floods from enriching the uplands with water and rich sediment. Instead, the land next to the river can become very dry and erode, thereby making large floods much worse when they do happen.

To learn more about how you can help preserve riparian zones, see Protecting our watershed: What YOU can do to help.