Bank stabilization
River/stream bank erosion is the scouring, undercutting or the
collapse of banks of water caused by the flow of water. The factors that
contribute to this type of erosion are the soil type, the velocity and the
volume of water.
Protection of the river/stream bank will lead to the
stabilization of the water courses, the protection of the farm from "being
eaten" by the water and making productive the area along the river or stream.
Methods of river/stream bank
stabilization
Methods of river/stream bank stabilization
A. Planting of trees, shrubs, bamboos or palms along the bank is
a vegetative method of stabilization whereby the roots hold the soil in place
and reduce the impact of water flow. Following are some pointers in stabilizing
river/stream bank by planting:
1. In the zone from low to medium water level, only
grasses and shrubs are allowed to be planted -the species that are able to
survive prolonged inundation and are flexible enough not to break in the water
current.
2. In the zone from medium to high water level, some tree, palm
or bamboo species can be planted with grasses and shrubs.
3. In the zone above the high water level, trees, palms or
bamboos are planted with or without shrubs.
Stabilization of river/stream banks
through planting
B. Construction of temporary and emergency measures. These
measures are usually applied in areas along banks that are already collapsed or
in danger of collapsing. These measures are used to support the more permanent
river/stream bank stabilization.
1. Rauhbaum Method -- This is the placing of dense and
well-branched trees, tree tips or bamboos along the bank. It is tied and
anchored by a strong peg and the butt end is pointing upstream. This measure is
used to protect the bank from the direct impact of water flow while waiting for
the establishment of the more permanent stabilization measures.
Rauhbaum Method
2. Temporary Groynes -- A series of temporary structures of
dense and well-branched trees, tree tops or bamboos are used. These structures
are placed pointing upstream, perpendicular to the flow of water and pointing
downstream in order to direct the direction of flow, reduce the velocity of
water and partly accept the deposition of soil sediments. The measure is used
only in wide and shallow rivers or streams.
Temporary Groynes
The measure is used only in wide and
shallow rivers or streams.
Plugging of river/stream bank
3. Plugging of river/stream bank - This is a temporary, measure
to protect banks that are in danger of collapsing by placing dense crowns of
brushwood supported by pegs along the eroded portion.
Slating pegs or posts
TABLE 8. RECOMMENDED PLANT SPECIES FOR RIVER/STREAM BANK
STABILIZATION (BY Region).
