Both Our Rivers Are Dying
Say Scientists 22nd February, 2001 Gundagai
Independent |
A
committee of scientists has told the NSW Government the Murrumbidgee, Tumut
and Murray Rivers should be listed as endangered. The Fisheries Scientific
Committee said all three river systems should be listed as endangered
ecological communities under the Fisheries Management Act 1994. The
poor state of the rivers' ecological systems is blamed on the release of cold
water from dams, the introduction of exotic fish species, the clearing of
riverside vegetation, the use of insecticides and salination.
5.4 million hectares of NSW already have sally groundwater and a further 12.3
million hectares are at risk. Salt
is a huge threat in the Murray-Darling system, "Last year the flow rules
delivered significant benefits to the river as a relatively small amount of
water set aside for environmental contingencies was used to piggyback on
naturally high flows from the Murrumbidgee's tributaries. "Wetlands
right along the river were inundated, triggering aquatic plant growth and
providing ideal conditions for frog, bird and fish breeding. As the water
level dropped, water from the wetlands drained back into the river, taking
with it food for many of the aquatic animals living in the river". The
River Management Plan highlights the processes that threaten the Murrumbidgee's
aquatic ecosystem. For instance, the Plan deals with fish management and
habitat including the management of introduced species, wetland watering and
riparian zone management. Other
possible solutions being considered are fish ladders on weirs, artificial
watering of wetlands and reducing cold water pollution from the dams. Kath
Bowmer also stressed that a wide range of community
programs were improving the health of the Murrumbidgee. These include the $1
million Bidgee Banks program run jointly by Greening
Australia and the Department of Land and Water Conservation. The program is
helping land owners to strategically fence and revegetate stream reaches in
the upper and mid Murrumbidgee catchment as well as providing off-stream
watering points for stock. In
the Kyeamba and Tarcutta catchments a nutrient
control program with in excess of $1 million worth of funds is helping to
rehabilitate eroding stream banks and gullies which are a major source of
phosphorus entering the Murrumbidgee. Both these problems are funded by the
Natural Heritage Trust. The
recommendations that much of the Murrumbidgee River be declared an endangered
Ecological community have highlighted the need for continuing the
environmental planning work of the community-based Murrumbidgee River
Management Committee. The
proposed recommendation by the Fisheries Scientific Committee reflects the
serious threatening processes affecting the Murrumbidgee River below
Burrinjuck Dam and the Tumut River below Blowering.
Damaging
processes include river flow changes, barriers to fish passage, river
temperature changes, introducing fish species, over fishing and clearing of
riparian vegetation. The
Murrumbidgee River Management Committee has been working towards improving
the problems indicated in the recommendation in both the Murrumbidgee and
Tumut Rivers for the past three years, Committee Chair, Kath Bowmer said. "While it will take a long time to
redress the problems of the Murrumbidgee River system, the River Management
Plan currently being finalised by the Committee will produce major
environmental benefits", she said. "These include the possibility
of an en-route storage to assist in the better management of flows in the
Tumut River. "One
of the key achievements of the Committee was the introduction of a set of
environmental flow rules three years ago. "These rules aim to improve
the health of the river and its aquatic ecosystem by mimicking the river's
natural flow variability. Concerns
over the health of the Tumut River were the forefront of a community forum
hosted by the Murrumbidgee River Management committee in Tumut last week. Chair
of the Committee, Kath Bowmer, said community
forums are being held in each town where the committee meets, providing an
opportunity to let the community know about the development of a River
Management Plan and to hear community concerns over river management. The
forum attracted representatives of local businesses. Tumut River Landholders
Association, Tumut Shire, Murrumbidgee Catchment Management Board, Committee
for the Rehabilitation of the Tumut River, Tumut Acclimatisation Society,
Tumut Fly Fishers and Gilmore Landcare. The
main concerns, Kath Bowmer said, revolved around
the high summer flows in the Tumut River. "As with most environmental issues,
there is a need to balance the sometimes conflicting needs of different
interest groups," she said. "The
high summer flows out of Blowering Dam are due to
water use requirements downstream. Unfortunately, these high flows are also
causing river banks to erode and rock walls have been put into place to stop
the banks slumping. A number of land owners commented that the rock walling
is stopping erosion and commended the Department of Land and Water
Conservation on its efforts, but the rock walling also causes problems for
fish habitat and, some believe, loss of tourism dollars due to the loss of
natural aesthetics." "As
part of the River Management Plan, the committee is investigating a number of
options to improve Tumut River health, including the feasibility of an
en-route storage." Other
issues considered by the committee in their meeting included the implications
of the new Water Management Act, the Murrumbidgee Catchment Management
Board's targets and strategies and the further development of the River
Management Plan. The
Murrumbidgee River Management Committee includes water user representatives
from the irrigation industry, environmental interests, local government, the
Murrumbidgee Catchment Management Boar, Aboriginal interests and government
agencies. |