Stream Bank Stabilization
Stream banks naturally erode as water wears away soil and rock that form their banks. As the erosion occurs streams establish a meandering course. StreambAdopt-A-Stream Logoank erosion, however, has been accelerated by land altering activities such as: stream channelization, straightening of streams, removal of vegetation along the stream, and the construction of impervious surfaces such as roads, concrete structures and rooftops along with other activities. Impervious surfaces significantly increase surface runoff and water velocity. When this happens streams make room by eroding the banks and bed, which results in a deeper and wider channel. Sediment and nutrients are extensively washed downstream. As sediment is deposited further down the stream it may decrease the stream’s capacity, which increases flooding and streambank erosion. Excessive sedimentation also degrades water quality and destroys fish and wildlife habitat. Healthy streams have some erosion and deposition when major storms occur. This erosion and deposition is more dramatic though when runoff is accelerated by urbanization.
Planting native trees, whose roots help stabilze the soil, can diminish the process of stream bank erosion. They also provide shade and cover for stream life and improve water quality. Their ability to withstand flooding, to stabilize soils, and to grow quickly in saturated areas make them ideal for revegetating stream banks. Another way to help slow the process of erosion on stream banks is to create a conservation buffer. Conservation buffers are strips or other areas of land in permanent vegetation. They help control pollutants and manage other environmental concerns. Filter strips, riparian buffers, field borders, grassed waterways, field windbreaks and contour grass strips are examples of buffers. Tree revetments are used to stabilize stream banks on small to medium streams. They are made by anchoring trees along a stream bank. The trees slow the current along the eroding bank thereby decreasing erosion. Silt and sand are deposited among the tree branches, which form good seedbeds for river species to take hold.
Planning development in a watershed in advance would help prevent stream problems in the first place. However, in the absence of planning it is recommended that restoration or stabilization techniques be used to minimize erosion and deposition effects.
Various pamphlets/websites can help you choose the right direction to go regarding stabilizing your stream bank. Some helpful websites are: