Annex. Reproduction of a page on “Roading” from the operational database.

Techniques Available

A. SIDECASTING & CUT AND FILL

Machinery

Crawler tractor with angle blade Hydraulic excavator Motor scraper Grader

Potential Adverse Impacts

· Sedimentation and runoff from roads and sidecast spill may cause reduction in water quality
· Visual impact
· Loss of productive forest area
· Reduction in slope stability on unstable sites

Methods of Reducing Adverse Impacts

· Identify and avoid unstable areas

· Locate roads on ridges or benches where possible and away from waterways

· Plan and mark road alignment prior to commencing earthworks

· Form watertables and install sufficient culverts and flumes to control run-off as soon as possible, and maintain

· Install flumes so that runoff falls on stable ground away from fill areas

· Step unstable batters, reduce batter slope or hydro-seed

· Channel run-off on to spurs where possible

· Filter run-off through vegetation before entering water course, or use sediment traps

· Keep spoil out of waterways

· Use cut and fill or end-hauling techniques on sensitive slopes

· Establish vegetation cover on batters and spill where necessary

· Avoid working in wet conditions

· Use excavator in sensitive areas

· Allow road to consolidate before use

· Maintain road surfaces, watertables, cutoffs and culver installations

Comment

Sidecasting is the least costly and most commonly used technique for roading. Road surfacing may be necessary, factors to consider are compaction, drainage, subsurface binding properties and gradient. Cut and fill techniques are used on steep or broken terrain, where surplus material can be moved short distances to provide fill.