This document compares the effectiveness of VeDver System Technology (VST) to other erosion control methods on a steep, unstable slope. VST involved planDng veDver, which formed an extensive root network that fully stabilized the slope within two years, preventing sediment runoff even after heavy rainfall. In contrast, previous attempts using hydroseeding, geofabrics, and shallow-rooted planDngs all failed to control erosion. The presentaDon shows VST is highly effecDve and cost-efficient for steep slope stabilizaDon compared to convenDonal methods.

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2. INTRODUCTION
This
presentaDon
shows
the
effecDveness
of
VeDver
System
Technology
(VST)
as
a
tool
of
bioengineering
as
compared
with
other
commonly
used
methods
to
control
erosion
on
steep
slopes.
The
site
was
on
a
highly
erodible
fill
materials
consisted
of
weathered
sandstone
and
sandy
soil.
It
is
on
a
very
steep
gradient,
averaging
45
degrees
and
up
to
50
degrees
at
some
secDons.
The
original
baVer
was
built
from
material
excavated
and
pushed
down
slope
for
a
home
site
on
a
very
steep
mountain
range
The
climate
is
subtropical,
with
cool
and
occasional
frost
in
winter,
and
wet
summer
with
prolonged
period
of
high
intensity
rainfall
and
occasional
cyclonic
downpour
This
presentaDon
shows
the
result
two
years
aXer
implementaDon
aXer
numerous
storms
and
recently
a
350mm
rainfall
over
a
5
day
period.

3. This
is
a
very
complex
site,
with
very
steep
gradient
in
two
direcDons,
with
slope
gradient
up
to
500
in
some
parts
100m
long,
up
to
500
400m
long,
up
to
450

4. Original
baVer
from
material
excavated
and
pushed
down
slope
for
a
home
site
House
House
100m
long,
up
to
500

5. Original
baVer
from
material
excavated
and
pushed
down
slope

6. House
Front
of
the
house
House
100m
long,
up
to
500

7. Hydroseeding
with
turf
grass
to
control
erosion
and
stabilise
the
baVer

8. Rilling
started
soon
aXer
Hydroseeding

9. Rilling
started
soon
aXer
Hydroseeding
House
100m
long,
up
to
500

10. Rilling
was
so
severe
that
a
geofabrics
was
used
to
cover
the
whole
baVer
to
prevent
further
erosion

11. House
A
very
elaborate
and
expensive
operaDon,
including
sand
bags
to
weight
down
the
geofabrics
cover

12. Lomandra,
a
shallow
rooted
ornamental
species
was
planted
to
stabilise
the
baVer

13. Despite
this
costly
measure
the
baVer
collapsed
during
an
average
summer
rainfall
and
it
was
rebuilt
with
imported
fill
materials

14. The
baVer
was
rebuilt
with
imported
fill

15. Concrete
blocks
was
built
as
retaining
wall
at
the
foot
of
the
baVer

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17. Laying
Georics:
Jutemesh

18. VeDver
planDng

19. VeDver
planDng

20. Six
months
aXer
planDng

21. 8
months
aXer
planDng

22. 10
months
aXer
planDng

23. Two
years
aXer
planDng,
aXer
slashing
Two
years
aXer
planDng,
before
slashing

24. Two
years
aXer
planDng,
aXer
slashing

25. Two
years
aXer
planDng,
prolific
growth,
2.5m
high
with
roots
to
at
least
2m
deep

26. PracDcally
no
sediment
in
downslope
drain

27. CONCLUSION
This
presentaDon
shows
the
superiority
of
VST
as
compared
with
other
commonly
used
methods
to
control
erosion
on
steep
slopes,
both
in
term
of
effecDveness
and
cost.
VST
has
passed
the
ulDmate
test
two
years
aXer
implementaDon
with
a
recent
rainfall
period
of
over
350mm
in
5
days.
In
addiDon
to
its
steep
slope
stabilisaDon
efficiency,
it
also
completely
prevented
sediment
moving
down
the
slope