Environmentally Sensitive Channel- and Bank-Protection Measures (2005) / Chapter Skim
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Appendix A - Descriptive List of Channel- and Bank-Protection Techniques
Appendix A - Descriptive List of Channel- and Bank-Protection Techniques
Pages 29-40
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From page 29... ...
Two to five structures are typically placed in series along straight or convex bank lines where flow lines are roughly parallel to the bank. Spurs, groins, and deflectors have no specific design criteria regarding crest height, crest slope, or upstream angle and therefore differ from vanes and bendway weirs.
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From page 30... ...
Variations include cross vanes and rock vanes with J-hooks. BENDWAY WEIRS Bendway weirs are discontinuous, redirective structures usually constructed of rock, designed to capture and then safely direct the flow through a meander bend.
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From page 31... ...
This technique represents an effort to achieve erosion control benefits available from a continuous stone toe and habitat benefits associated with spurs. COCONUT FIBER ROLLS Coconut fiber rolls are manufactured, elongated cylindrical structures that are placed at the bottom of streambanks to help prevent scour and erosion.
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From page 32... ...
Live brushlayering provides enhanced geotechnical stability, improved soil drainage, and superior erosion control. It is one of the most effective ways to establish vegetation from live cuttings.
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From page 33... ...
LIVE STAKING Live stakes are very useful as a revegetation technique, a soil reinforcement technique, and as a way to anchor erosion control materials. They are usually cut from the stem or branches of willow species, and the stakes are typically 0.5 to 1.0 m (1.5 to 3.3 ft)
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From page 34... ...
Posts and poles are also excellent candidates for combination with other structural methods, for example, LWD structures, vegetated gabion baskets, live cribwall, and cross vanes. LIVE FASCINES Live fascines are bundles of live (and nonliving)
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From page 35... ...
Rootwad revetments and tree revetments are primarily intended to resist erosive flows and are usually used on the outer bank of a meander bend when habitat diversity is desirable and tree materials are available and naturally occurring. LIVE BRUSH MATTRESS A live brush mattress is a thick blanket (15 to 30 cm [6 to 12 in.]
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From page 36... ...
A gabion mattress can be used as either a revetment to stabilize a streambank or, when used in a channel, to decrease the effects of scour. Live cuttings are introduced through the rock filled mattress and inserted into native soil beneath.
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From page 37... ...
RIPARIAN BUFFER AND STREAM OPPORTUNITIES LIVE GULLY REPAIR Live gully fill repair consists of alternating layers of live branch cuttings and compacted soil. This reinforced fill can be used to repair small gullies.
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From page 38... ...
If a constructed or modified channel lacks such features, adding boulder clusters may be an effective and simple way to improve aquatic habitat. NEWBURY ROCK RIFFLES Newbury rock riffles are ramps or low weirs with long aprons made from riprap or small boulders that are constructed at intervals along a channel approaching natural riffle spacing (5 to 7 channel widths)
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From page 39... ...
As the fascines begin to root and sprout, the root system acts like a filter medium, stabilizing fine particles and reducing piping and sapping. Live pole drains provide drainage and stabilization immediately after installation and, once established, produce roots that further stabilize bank and levee slopes.
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From page 40... ...
SLOPE FLATTENING Flattening or bank reshaping stabilizes an eroding streambank by reducing its slope angle or gradient. Slope flattening is usually done in conjunction with other bank-protection treatments -- including installation of toe protection, placement of bank armor, revegetation, and erosion control -- or installation of drainage measures.
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