As a person with no academic qualifications beyond the old leaving school certificate but with the experience of having lived my entire life, (83 years) on the banks of or within a few kilometres of the Namoi River at Carroll I have watched the recent debate on the management of the Murray Darling basin with bewildered disbelief. As children in the late 1930's and early 1940's we came home from school each afternoon, and went straight to the river to swim and to fish. There was no TV or electronic device to distract one at that time, so we literally spent hours each day at the river. In those times the river frequently stopped running, and on some occasions the number and size of the water holes shrunk considerably. We did experience very occasional fish kills, mainly of bream and cod, and occasional fish deaths when a particular muddy fresh came into a clear river after a long period. I don't know if blue green algae existed in those times, we occasionally had a slimy red scum on the edge of a water hole.
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Then in the 1950's Keepit dam was completed, and the river changed forever, and I cannot believe anyone would wish to have no dam there. The government of the day approved the construction to stabilise a developing irrigation industry, based on the premise that the increased taxation revenue from increased agriculture production would eventually pay for the construction and maintenance of the dam. The expansion and development of irrigation took some time and for many years Keepit Dam kept the river running at a substantially higher level than would have been the case if there were no dam. Many people have come to the false belief that this was the natural river. Since those days irrigation has expanded to the extent of more demand than supply and over a decade in recent times was spent in allocating the available water between the towns dependent on river water, the environment and the irrigation industry. This formula had the agreement of all parties, every sector probably feeling they gave up more than the others. The boating and fishing recreational sector has enjoyed many years of activity on the dams with the only expenses associated with the amenities provided and no contribution to the maintenance and operation of the dams. It is my understanding that all other river valleys feeding the Murray Darling Basin went through a similar process. There were provisions for a review of the process after a number of years, and this recently took place with some alterations to the cap in some valleys.
If Keepit Dam and Chaffey Dam and Copeton Dam and others on the Darling River system had not been built for irrigation, then the condition that exists at Walgett and other towns at this time would have begun 1 or 2 years ago and there would be very few water holes existing at all at this time. The wrecked paddle steamers in the bed of the Darling are testament to the fact that it has stopped running many times previously in the history of settlement and undoubtedly in times before that. And so we arrive at the current debate, with South Australia's Royal Commission Report, The Wentworth Group of Scientists, South Australia's self appointed protector of the environment The Hon Senator Sara Hanson Young, amid many others castigating the performance of the Murray Darling Basin Plan and staff who work for the body who implement it. Quite a large predominance of South Australians in this group. I find it strange that none of these even mentioned the earliest and still the greatest impacting event on the environment of the Murray River, the construction on the Barrages between Lake Alexandrina and the Coorong. For thousands of years the Murray River emptied into the sea through a healthy salt water estuary. Almost with the stroke of a pen and no environmental impact study, the construction of the barrages converts this estuary to a fresh water lake. I have taken my information on the Barrages from The Lower Lakes Local History web site.
The barrages keep seawater out and create an artificial exclusively freshwater environment. They were constructed between 1935 and 1940 to create a pool of freshwater to stabilise the river level for both irrigation and transportation.
From the report” Ecological Assessment of the Lakes and Coorong Fishery” September 2005.
Construction of the barrage network transformed about 87 per cent of the original estuary into a freshwater catchment (Lake Alexandrina and Lake Albert) changing the natural flow regime, which has altered the morphology of the Murray Mouth and imposed significant impediments to the natural fish passage. This had a generally negative impact on the overall health of the ecosystem, in particular the habitat available for a range of estuarine dependent fish species, native plants and water birds. Use of the barrage network has significantly reduced the flow of the water into and out of the river mouth under tidal influence. Because of this the Murray Mouth approaches closure more frequently than would have occurred naturally.
Extract from interview with Jim Marsh barrage superintendant at Goolwa September 1999 by Rose Geisler.
“ When you get back to the size of the estuary reducing by 87 per cent, they reduce what we call the tidal prism. This is the force, the column of water that surges in and out of the Mouth daily by just the effect of the tide That was enough to keep the Mouth clear. When they reduce the size of the estuary, they reduce the size of the tidal prism and greatly reduce the velocity and volume of that water passing in and out. Ever since 1945, we have had yearly a net gain of sand, and that was first shown up fairly soon after, with the formation of Bird Island. That wasn't there before they built the barrages. This also had an effect on the native fish,- the Mulloway, Mullet, Flounder, Bream all need the estuarine conditions to complete their breeding cycle. Especially the Mulloway, they use the Coorong now- which is all that is left of the estuary- they used to use the whole lower lakes as a nursery area.”
Not only do the afore mentioned groups and individuals neglect to consider the monumental affect of this construction, but they demand allocation of an incredible volume of water each season to evaporate in the preservation of this artificial fresh water construction. They talk of the deterioration of the health of the lower Murray. Perhaps some in South Australia can remember their families talking of 1915,when the sea water penetrated up to Mannum, they were catching Mullet at Mannum, and there was even a sighting of a shark at Tailem Bend, and a Dolphin at Murray Bridge.
Yes many of our rivers are in a sorry state right now as they have been before and will be again. But an incredibly large group of representatives of diverse organisations, have in good faith negotiated a plan which deserves to be nurtured and enhanced. Abuse, insults and suggestions of throwing present agreements out of the picture will only lead to anger, conflict, and financial hardship for individuals, families, communities and society in general.
I am proud to have been an irrigation farmer. I have never owned or benefited financially from a river licence. I have owned a groundwater licence since the early 1960's. We surrendered 75 per cent of our allocation in the early negotiations of the groundwater plan associated with the Murray Darling Basin Plan. I don't know of any irrigator who has not made significant financial sacrifice, to be part of the community endorsing the Murray Darling Basin Plan
Bill Weakley
Gunnedah
