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Chapter 4 - Best Management Practices for Erosion and Sediment Control <br /> • 4. 07 BRUSH BARRIER <br /> ( ES BMP 1 .07) <br /> ' Definition <br /> A temporary sediment barrier constructed at the perimeter of a disturbed area from the <br /> ' residue materials available from clearing and grubbing the site . <br /> Purpose <br /> To intercept and retain sediment from disturbed areas of limited extent, preventing <br /> sediment from leaving the site . <br /> Conditions Where Practice Applies <br /> Below disturbed areas subject to sheet and rill erosion , where enough residue material is <br /> available for construction of such a barrier. <br /> Planning Considerations <br /> Organic litter and spoil material from site clearing operations is usually burned or hauled <br /> away to be dumped elsewhere . Much of this material can be used effectively on the <br /> construction site itself. During clearing and grubbing operations , equipment can push or <br /> dump the mixture of limbs , small vegetation and root mat along with minor amounts of soil <br /> + and rock into windrows along the toe of a slope where erosion and accelerated runoff are <br /> expected . Anchoring a filter fabric over the berm enhances the filtration ability of the <br /> barrier. Because brush barriers are fairly stable and composed of natural materials , <br />• maintenance requirements are small . <br /> Design Criteria <br /> A formal design is not required . <br /> Construction Specifications <br /> 1 . The height of a brush barrier shall be a minimum of 3 feet (90 cm) . <br /> 2 . The width of a brush barrier shall be a minimum of 5 feet ( 1 . 5 m) at its base . (The <br /> sizes of brush barriers may vary considerably based upon the amount of material <br />+. available and the judgment of the design engineer.) <br /> 3 . The barrier shall be constructed by piling brush , stone , root mat and other material <br /> from the clearing process into a mounded row on the contour. <br /> If a filter fabric is used (Plate 4.07a) : <br /> 4 . The filter fabric shall be cut into lengths sufficient to lay across the barrier from its <br /> upslope base to just beyond its peak. Where joints are necessary, the fabric shall <br /> 4-31 <br />