This
is a letter written to the Conservation Council of South Australia newsletter.
CCSA Brief:
Dredging of Eight Mile Creek
Eight Mile Creek was
so named because it is located eight miles to the east of Port MacDonnell.
Eight Mile Creek is the interconnection from Ewens Ponds to the sea, approx
2.3 kilometres in length, and as such it is a critical part of the greater
Ewens Ponds system, carrying something in the order of 100 Mega litres
(approx 3 m3 per second) of water to the sea each year from the Ponds.
Ewens Ponds consists
of several freshwater ponds in series, formed by water pushing up out
of the ground in a series of springs that actually continue past the Ponds
and down Eight Mile Creek itself. The Ponds are fairly large in size,
each extending to a depth of about 9-12m, and spread over a distance of
around 300-400m, interconnected by narrow channels.
At one stage the
third Pond contained a cave; today only the remnants of this remain, as
it was virtually destroyed through the use of explosives used for the
fishing of native freshwater eels some 30-40 years ago.
The Ponds, their
interconnecting channels, and Eight Mile Creek provide an excellent location
for snorkelers and divers alike, who visit the area all year round to
admire the exquisite beauty of the site.
This beauty is provided by stunning waterweeds of various shades of greens
and yellows, intermingling with the blues of the water, the browns &
whites of the mud and limestone bottom, and the natural sunlight.
Visibility seems
to reach infinity, as one can see as far as possible in the crystal clear
waters that contain various species of fish, including the protected (and
threatened) Ewens Pygmy Perch and Southern Pygmy Perch, which live off
mosquito larvae. The Pygmy Perch can be found amongst the weed that grows
in the creek, as they are not strong swimmers and avoid those areas of
strong current flow not containing weed. There are also Galaxias fish,
native freshwater crayfish, marron and several other species that I do
not know the names of.
About 40-50 years
ago drains were run into Eight Mile Creek in order to lower the water
table, so that the surrounding wetlands could be converted to dairy pasture.
Today the dairy farms still exist, and so do the drains. A plaque at the
entrance to Ewens Ponds marks the original water level of the area.
In order to maintain
the drainage system our predecessors started the practice of dredging
Eight Mile Creek, from the Ponds to the sea, as the removal of the waterweed
causes the water to flow significantly faster. This results in a drop
in the water level, which in turn more effectively drains the surrounding
land.
Imagine my surprise
last year whilst snorkelling down Eight Mile Creek from the Ponds to sea,
to discover at a point about one-third to one-half of the way down, that
the stunning beauty of the creek suddenly and dramatically turned to silty
water, green from the algae contained within it (photos available).
How could this be?
The South-Eastern
Water Conservation & Drainage Board, with approval from the Government,
still continue the practice of dredging Eight Mile Creek, despite this
creek being the most significant freshwater creek in the South-East, possibly
in Australia, as I know of no other creek of such diversity & beauty,
and which is visited by so many tourists, including many overseas visitors.
Try to imagine two
caterpillar tractors, one on each bank of the creek, pulling between them
a large steel cable about 20-25mm in diameter, to which is connected a
dredge-shaped drag made from large steel girders possibly weighing as
much as two tonnes. Try to imagine these tractors pulling that dredge
up and down the creek for two days, at a speed of about 4-5 kph, under
a 20-30cm high wave of water.
And try to imagine
the devastation as the unique native waterweed containing the threatened
and protected Pygmy Perch is carried out to sea, and then washed back
onto the beaches by the tide, so that almost a kilometre long strip of
beach is covered in rotting native waterweed.
Try to imagine the pelicans, and the 600 or so seagulls, along with other
waterbirds, as they fight for a feed of our endangered freshwater fish.
And try to imagine
not being sent to gaol if you or I did that!
This method is currently
employed to devoid a 1.2km section of Eight Mile Creek of its vegetation,
which totally devastates that section of the creek from the Spencers Pond
(man-made) outlet to the bridge adjacent to the mouth of Eight Mile Creek.
(I understand that until fairly recently Eight Mile Creek was dragged
all the way from Ewens Ponds Conservation Park.)
This is a practice
of the past that was acceptable in the day when the land was being cleared
of anything resembling trees and scrub. Why is it that this practice is
still allowed long after land clearing has been legislated against?
This must not be
allowed to continue within any part of Eight Mile Creek; it must surely
be possible to drain the adjacent land through means that do not interfere
with this natural environment.
The draft Management
Plan of the South-Eastern Water Conservation & Drainage Board 2003-2006,
listed amongst its 'Statutory Functions and Obligations' (South Eastern
Water Conservation & Drainage Act 1992), "The enhancement or
development of natural wetlands and the natural environment generally
in the South East".
I believe the South-Eastern Water Conservation & Drainage Board should
receive our every encouragement in this endeavour.
Your help in changing this situation is sought; the Government must realise
this practice is no longer acceptable.
Yours sincerely
Neville Skinner
|