Constructing a brushlayer with a wood terrace. The terrace is optional, but provides additional support. Because the terrace (which is deadwood) is not integral to the design, brushlayers can still be considered to be a soil bioengineering, rather than biotechnical stabilization technique.

 

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Brushlayers are similar to live fascines in that cuttings are planted densely and horizontaly along the contour instead of vertically. However rather than using cuttings in 2 to 3 meter lengths, laying lengthwise parallel to the contour, cuttings in a brushlayer are much shorter (1 meter), and are driven in perpendicular to the contour. The purpose in doing so is produce plants with roots deeper in the soil in order to provide greater support and slope stability. Live fascines by comparison produce shallower root systems that are more useful in holding soil against surface erosion.

Brushlayers are composed of horizontal lines of cuttings driven into a trench perpendicular to the contour, and backfilled.

 

The following spacing guidelines apply to installation of brushlayers on slopes:

Slope_ __slope distance between trenches ____Max. slope length

____________wet slopes___dry slopes

2:1 to 2.5:1____1 meter_____1 meter ____________5 meters

2.5:1 to 3:1____1 meter_____1.5 meters__________5 meters

3.5:1 to 4:1____1.5 meters___2 meters___________6.5 meters

 

Continued: Live pole drains

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