How do they work?
The large trees on the bank next to the river send roots deep into the bank helping to stabilize it from erosion. The overstory canopy of these big trees covers portions of the river protecting it from too much sun and helps regulate the river's temperature. The understory trees and shrubs do much of the same as the overstory trees. They both contribute to the circle of life in and near the river providing food and shelter for all the fauna and flora needed for stream health. Behind the overstory and understory trees and shrubs there should be a zone of native grasslands. This zone slows water, and collects sediment and chemicals that would otherwise enter the water and impair the river's health.
What would be the ideal plant life in a Riparian Buffer?
All levels of the riparian buffer should be a variety of native trees, shrubs and grasses. These varieties will bring more balance to the life of the river and continue to contribute to the circle of life that has developed over thousands of years. Here is a link from the Virginia Department of Forestry with a list of common Virginia riparian plants.
So how much Riparian Buffer is needed?
This would be dependent on the size of the stream or river, the type of land surrounding it and its use. Buffers less than 35 feet usually cannot sustain aquatic resources; widths of 35 to 100 feet are needed under most circumstances. Buffer widths toward the lower end of the range support some of the physical and biological needs of the stream ecosystem, especially on small streams. Those at the upper end of the range are more likely to protect the physical, chemical, and biological characteristics of larger rivers and aquatic resources.
Here are three great internet resources for planning and planting riparian buffers for healthy waterways:
Cuyahoga River Community Planning Organization:
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Guidelines for Riparian Buffers and Stream Restoration from the USDA
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A plethora of stream restoration information from the USDA
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Protecting Our Waterways: Creating a Successful Riparian Buffer from the Dan River Basin Association
Filter- it removes harmful substances from runoff or changes them into less harmful substances so they don’t contaminate our water
Transformer- it can change a unhealthy waterway into a healthy waterway
Rumble Strip- it slows down water to mitigate erosion
Bucket- it holds nutrients that otherwise might end up in the river causing algal blooms
Home- it houses terrestrial/aquatic plants and animals
Breakfast Lunch and Dinner- it contains trees that provide falling leaves and falling insects which are the food base for the aquatic ecosystem
Highway and Roadside Inn- it provides travel corridors for wildlife to move from place to place and provides cover for rest, water and food
Pillow- it provides cover for rest, water and food for migrating birds
A pair of Sunglasses and or an Ice Pack- it contains large trees that shade and protect from the Sun, cooling waters which increases oxygen to support fish and other aquatic life
What do Riparian Buffers consist of?
Riparian buffers consist of native vegetation zones that help protect the water from too much sun and adjacent land use. These vegetative zones will be different depending on the body of water they are protecting, the land's physical attributes surrounding the water and the land use that is nearby. In our area one of the biggest needs is to buffer agricultural use. The Middle River is over 70 miles long and has many tributaries running through some very dynamic agricultural land. The buffers for the Middle River should include large trees right on the bank next to the river then understory trees and shrubs that fill in gaps in the overstory trees. Behind the overstory and understory trees there should be a zone of grasslands. Best practices for planning as well as the planting of Riparian Buffers is covered in the links below.
Riparian Buffers
Sometimes called a stream buffer or riparian zone.
Riparian- refers to things alongside a river bank, wetland or other body of water. It is usually used in reference to physical, biological and chemical processes but can also include laws governing these zones.
Buffer- an area or zone next to a wetland, stream, river or other body of water that is essential for its health.
A great way to explain Riparian Buffers is to use metaphors. Look at these common terms we all know to learn more about what a Riparian Buffer does.
A Riparian Buffer is a:
Sponge- it holds water and mitigates flooding
Straw- it pulls water out of the ground and into the atmosphere through tree and plant respiration
Black Walnuts for Riparian Buffers,
with Philip Davis, NRCS in 2019
How to Use a Hoedad for Tree Planting, with Joe McCue