Planning and implementing forest operations to achieve ... - Woodweb

On pulled-back roads, ideally, material should be
redefined so as not to restrict their flow with the placed
placed in the order that it came out, large coarse
pullback material.
material on the bottom, mineral soils next, and then
organics on top. If there are not enough organics to Cross ditches vs. waterbal's
have a flail 300ram (1 foot) layer, then quantifies of
good organic material should be placed (dumped) in In the past there has tended to be some confusion as to
mounds 3 Meters (10 feet) apart to provide the best
the definition and use ofa crossditch and a waterbar in
enhanced planting sites,
the deactivation plan;
Mounding as a general technique to enhance a planting
site not only provides shelter from icy winds in the
juvenile years, but the south facing slope now is
warmed by the sun and, in effect, creating a miniclimate.
Seedlings can also now be planted at different
levels on the mound to suit the varying climatic needs
of the different species.
The cross ditch is to drain the ditch line across the road.
Whereas the waterbar stops and redirects the
accumulated rain water on the roads surface.
Cross ditches
The cross ditch is, as a breakdown of its name implies;
cros¢, as to cross the road and ditch, as to drain the
Pullback of over-steepened sidecast material ditch line. It should be as deep as the ditch that it is
draining. The term "cross ditch" is also generically
The degree of pullback is commensurate with used when re-establishing a natural stream crossing.
rendering the hillside stable. Generally, excess For permanent deactivation it is recommended the
material is removed from as far downslope as the
original shape of the watercourse be re-established by
excavator can reach. The operator should aim to removing all fill material from the gully to allow
remove the excess material down to the original duff
unrestricted water flow in extreme event situations.
layer. Provided the area is stable and it is safe to do so, This fill material, if left, could be transported during the
the pulled-back material is placed against the cut-bank storm event.
and on the outsloped and scarified road surface. ('Note:
Natural drainage must be restored and maintained)
The cross ditch should also be constructed so as not to
"pond"or retain water at its inlet which could saturate
When rehabilitating older roads from earlier or place an undue weight on the slope. It should follow
construction methods when side cast material was the natural, pre-existing grotmdline as closely as
acceptable, it may be necessary to prescribe that the possible.
hoe "ramp down" to gain extra reach..But, considering
that the area that you are working on is probably Skew - "to place at an angle" When draining a
unstable ground due to water saturation, buried
ditchline with a cross ditch, and the road is at an uphill
organics, vegetative slip layers and/or uncompaeted
or downhill grade or percentage, the cross ditch should
sideeast, this could be unsafe to recommend. An be "skewed" a certain amount from the 90° angle to the
answer that I have used is to prescribe the use of a
road direction.
cable dragline that can safely reach down the slope for
long distances and can also place the pulled material As a guide, the skew angle should be a minimum of
against a high cut bank to help buttress that slope. A 35* and increase 1° of skew for every increase in grade
large machine of 50 metric tonnes (100,000+ lbs) is percentage. As an example, a road with an 8 percent
again too heavy for safety, as the machine is placing an grade would have a recommended cross ditch skew of;
undue weight on a previously identified unstable slope. 35° (skew) + 8% (grade) = 43° (crossditch skew).
I have usually recommend a smaller machine in the 25
metric tonne (60,000 lbs) class, that has a 2 cubic A deactivation operator will not have instruments with
meter (2 yards) bucket capacity for bulking out which to ascertain the basis figures to calculate culvert
material, yet is light enough on the slope to address the skew. From experience, the operator often will be able
safety factor,
to estimate quite accurately percentages and angles.
However, are you prepared to stand by the chance of a
Drainage concerns for pulled-back sidecast failure of an incorrect installation? And a subsequent
material liability in the event of that failure? I suggest, in order
to eliminate the risk factor, that it should not be left up
Naturalstreams, bank seepages, seasonal streams, and to theoperator. That extra few minutes taken to
dry watercourses, must have their drainage channels identify the outfall and hang a ribbon will be well worth
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