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.