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Projects for Improving Riparian Habitat

The riparian area is the land beside the water.

The Forestry Action Committe is preparing plans for Sucker and Kelley Creeks to restore the streams to a more sinuos and natural flow.

What is Sinuosity?

Sinuosity is the curves in the stream

The more sinuous a stream is the more stable it is because the water takes a longer, slower path as it travels down the valley. When the water slows down as it goes around curves it deposits some of the sediment it carries. Riparian vegetation grows in these patches of sediment.

What Helps Sinuosity?

Riparian Vegetation

A stable stream bank is a complex network of vegetation, roots, wood, and sediment. If there are many layers of roots and vegetation, they offer a powerful resistance to bank erosion. Riparian vegetation also helps lower the water temperature by providing shade. If the water gets too warm, it can be fatal to salmon.

Large Woody Material

Random events such as landslides and windstorms deliver trees and large wood to streams. Large down trees promote curves in the stream channel. They also catch sediment and help stabilize gravel bars. Large wood provides habitat diversity such as pools and side channels. Large wood also helps slow down water during winter storms. Baby Coho salmon winter in Sucker Creek and the large wood provides them protection from the swift winter current.

Side Channels

Side channels provide space for water during winter storms and floods. Side channels help reduce erosion by slowing down water as it flows down the channel. Side channels also provide protection for baby salmon.

What Degrades Sinuosity?

Removal of Riparian Vegetation

Erosion occurs when a stream has more energy applied to the bank than the bank can withstand. Removal of vegetation or simplification of root depths along water ways decreases the amount of strength in the stream bank, making it more susceptible to erosion.

Removal of Large Woody Material from the Stream channel

In the past people removed much of the large wood from streams. Today we have better understanding of the benefits of large woody material and the role it plays in stream health and bank stability.

Sediment Overload

When a stream levels out as it comes out of the mountains it drops sediment which makes the stream bed shallower. Gravel bars widen, sometimes causing erosion on opposite banks. Pools and swimming holes fill in, reducing the quality of fish habitat. The channel becomes wider and shallower, and the stream course more erratic.