Environmental Assessment
Volume C-6
Slurry Pipeline
Reclamation and Closure
Ambatovy Project
211
January 2006
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Natural vegetation will be retained near water crossings as long as
possible during construction to reduce the time that bare soil is exposed.
•
Earth cuts and fills will be as shallow as possible, consistent with the
geometric standard being constructed.
•
Areas of concern will be protected with rip-rap, geotextiles or other
methods as required.
•
Cross drains, parallel ditches and diversion berms will be installed on
disturbed slopes susceptible to water erosion to divert runoff into
vegetated areas adjacent to the RoW.
•
Diversion berms will be constructed to minimize the velocity of runnoff
water, and extend from the trench line to the undisturbed edge of the
RoW.
•
Construction and reclamation will be completed sequentially, thereby
minimizing the area disturbed at any one time.
6.3.4
Watercourse Crossings
Watercourse crossings, stream bank, and riparian zone impact mitigation general
considerations are described below.
•
Streams, riparian management areas and machine-free zones will be
identified on plan/profile sheets. Machine-free zones will be flagged.
•
Clearing width will be reduced to the minimum needed for construction
of a watercourse crossing or a water body identified as being sensitive.
•
Waste material, including grubbing and strippings, will not be piled in
areas that may block the flow of water.
•
Initial stream crossings will be by temporary crossing structures such as
skid or log bundle bridges. Initial crossings on fish bearing streams will
be by temporary clear-span bridges.
•
Permanent bridge structures will be used on all fish-bearing
watercourses crossed by the road along the pipeline RoW.
•
Trenchless water crossing methods, if technically feasible, will be
considered at sensitive fish-bearing watercourses.
