Impacts of humans within the park
Current human impacts on Minnamurra Rainforest began with the
process of logging. Today there are still human impacts but they
are more controlled. These impacts are both negative, and positive.
Early impacts were negative with the removal of red cedar timber
creating subtle changes to
the ecosystem of the rainforest, whilst some of the more recent
impacts have been to repair (or manage) past impacts.
Stop 5 and Stop
7 both document some of the past human impacts that have occurred
at Minnamurra. In more recent times, the changes to Minnamurra
caused by humans have been related to the use of the area for
recreation. When Howard Judd took over the running of the reserve
on behalf of Kiama Council in 1945, the reserve had many walking
tracks with wooden plank bridges constructed to cross the river
and tributaries. During Mr. Judd's time as caretaker for the park,
the facilities were expanded to include a museum (built in 1968),
a kiosk (built in the 1950s), a picnic shelter and two natural
stone toilet blocks which use a septic pump out system. The human
impact of these developments was mainly in the impact that improved
facilities have on increased visitation, although the septic system
also has an impact. By 1980, the park was receiving 100,000 visitors
a year, with the busiest days having around 1500 visitors.
This increased visitation was linked to the heavy use of the
main walking track to the falls, which were experiencing severe
degradation by 1980, with the roots of trees along the track being
exposed by trampling.
The septic system, for example, would have had some impact. Although
it was a pump-out system, some of the waste water from the system
to seeped into surrounding soil, allowing it to enter the river
system increasing the nitrogen and phosphorus in the river. Therefore
there would be an increase in the growth of algae in the river
and possibly change in the plant species represented in the river
and riparian rainforest along the rivers. In addition, to supply
these facilities with water would require that water be removed
from the river. Each time someone flushed the toilet, around 11
litres of water would be removed from the river system and the
rainforest.
In the rest of the park there was a varying quality of land,
with the inner core (20 hectares) being mainly natural, but the
north-eastern area of the whole 401 hectares suffered from clearing
for grazing in the 1930s and subsequent weed invasion. In addition,
in 1939 and 1960, fire swept through the park, altering the ecosystem
and allowing weed invasion. In one area on a steep slope, beside
the river facing north -west, the 1960 fire was followed by a
flood which removed all the regenerating plants from the slope,
leaving it open to invasion by lantana.
Although things like floods are not a human impact, fires are. The impact of the 1960 flood is still felt today because of the prior impact of fire, which was almost certainly started by humans.
So by 1980, the park had undergone various human impacts from
early timber cutting and grazing, to more recent recreational
impacts such as trampling, impaction of roads by large numbers
of vehicles, fires and weed invasion. In addition the facilities
provided for visitors, like the kiosk and toilets, would have
increased the waste in the area that had to be disposed of.
The National Parks and Wildlife Service of NSW took over management
of the park in 1986 and consequently human was managed more actively,
with a somewhat larger financial budget behind it. Human impacts
during this period have been more positive than negative and have
included the establishment of a visitor centre, where the aim
is to educate visitors about the site they are about to enter,
as well as providing facilities such as a kiosk, toilets and picnic
grounds; walking tracks have been overhauled and a series of boardwalks,
suspension bridges and brick pavers now replace the degraded system
of tracks; and areas of the site which were degraded by prior
disturbance, such as clearing for farming, have undergone regeneration.
The bulk of the track is a boardwalk that elevates walkers off
the fragile floor of the rainforest. Finally, the facilities for
cars and buses to park have been improved, as has access from
the car parks into the rainforest, so that this area does not
become as degraded as it was in the past.
The result of all this work has been that initially the level
of human impact to the park was much greater than earlier projects
(i.e. somewhat negative) to make the park accessible and provide
visitor facilities. In the past, cars parked on cleared areas
of ground; however, today they park in specially constructed bays
which are sealed and represent in themselves much greater human
impact than the previous carparks. The positive difference is
that the disturbance created to build these carparks will help
later reduce out-of-control human impacts, such as cars parking
in areas that are not actually car parks, but become car parks
after 10 cars have destroyed the fragile vegetation that was growing
there.
This same principle applies to the boardwalk. The negative impact
of building the boardwalk means that machinery and equipment to
build the boardwalk were brought into the forest, and the path
of the boardwalk would have to be partially cleared of vegetation.
However, in the long term, this impact is positive in that it
protects against the increasing impacts of visitors on tracks
that get muddy and slippery, causing people to walk around them,
through the fragile forest, creating more areas of degraded forest.
So the impacts on the forest have been increased in the short term to bring about positive impacts. These impacts have been to allow people to continue to visit and use the area (and in fact increase the numbers of people the park can cater for), but at the same time to actively promote the conservation of the park in the long term, to the point where some of the past damage might be able to repair itself through regeneration of the rainforest.
Today the human impacts on the rainforest are a direct result
of visitation to the park. Visitation to the park has increased
from the 1991/92 financial year, when 71 082 people visited, to
a peak in 1994/95, when 137 942 people visited. This growth, shown
in graph 8A, was a result of the new works which the National
Parks and Wildlife Service had undertaken to restore the park,
which culminated in the park winning Environmental Tourism Awards
in 1993 and 1994. In addition, in 1994, the new track to the upper
falls was reopened after many years of closure following its need
for repair and a rock fall.
The peak in visitation has levelled off to 106 468 in the financial
year 1999/2000. The park is easily able to maintain present numbers
of visitors, with the hope to increase the numbers of weekday
visitors, such as school students, so that more people see the
park but the load of visitation is spread throughout the week.
When the peak numbers were reached in 1994/95, the park's facilities
struggled to keep up with demand, with long lines of cars waiting
to enter the park on the weekend. This was caused by a lack of
parking and the need to stagger the sheer volume of people in
the rainforest. Too many people would detract from the experience.
The negative human impacts of this visitation at its highest
was increased pollution from cars sitting in lines waiting for
entry, increased waste as people brought in and consumed food
on the site, as well as increased use of toilet facilities. The
increased use of toilet facilities leads to an increase in the
use of water from the river, just as it did in previous times.
Because the water from the river is no longer of high enough quality
(see: external human impacts
) for use in washing and toilets for visitors, it is now specially
treated through a water treatment system that uses UV lamps to
purify the water of organisms such as E.coli, cryptospiridium
and giardia. The system shown in photo 8H passes the river water
across the UV lamps before the water is stored in holding tanks
at the visitors centre.
The sewage and waste water produced from the visitors centre
is then carried off the site by Kiama Council to the Bombala treatment
plant. This impact on the park is not viable in the long term,
because it is taking water from the environment, and in drought
years this is water that cannot be spared in large amounts. Long-term
projects to reduce this impact include an "Envirocycle" system
of sewage and waste water management, which allows the water to
be treated on site in an environmentally safe manner and the water
produced redirected back into the visitor centre's toilets for
further use. This would reduce the use of river water by 70%.
Other impacts on the site by humans can be non-specific in that
they are related to the particular visitor or group. Some groups
will adhere to NPWS regulations and have minimal impact on the
site, aiding conservation of the rainforest by visiting and being
educated about conservation of rainforests generally. Other visitors
are not so light in their impact and will carry out activities
contrary to NPWS regulations, increasing their impact on the rainforest.
These activities might include disturbing fauna on the site, damaging
plants and dropping rubbish or waste along the paths and in the
rivers. Control of these types of visitors is hopefully achieved
by the education they receive in the visitors' centre, giving
them an appreciation of the conservation values that NPWS is striving
for.
Over time the human impacts on the park have varied from quite
severe to those that are aimed at controlling future impacts.
Some of these impacts are further discussed with regard to the
Management of Minnamurra
which reflects the positive actions that humans are now taking
to protect Minnamurra.
|
 |
| 8A. Visitation figures
1991-2000 |
|
 |
| 8B. Minnamurra Falls |
|
 |
| 8C. Boardwalk |
|
 |
| 8D. Suspension bridge |
|
 |
| 8E. Sealed bus parking
area |
|
 |
| 8F Sealed car park |
|
 |
| 8G Boardwalk along ground |
|
 |
| 8H. UV water treatment
unit |
|
|
|