19 February, 2010
Water Management
As of today just under 1,400,000 megalitres of water has flowed down the Darling River past Bourke since Christmas. Water "saved for the river" as a consequence of the Government buying Toorale Station and its water licenses, remains at 10,000 megalitres-0.7% of the flow since Christmas.How's that for an investment of $23.75m.?
13 February, 2010
Lakes-Letter to The Australian 13th February,2010
Could someone please explain to me (As one lakes region comes to life, another is saved from death-The Australian February 13th-14th) why returning the Lower Lakes (Alexandrina and Albert) to more like their natural state and allowing sea water to enter as it always did when upstream rainfall and flows were low, would be such a "natural disaster" equivalent to "death"?
10 February, 2010
River Management
Letter Sent to the Sydney Morning Herald on 10.02.10
Water Management in the Murray Darling Basin
Paul Myers (Only rain can solve riddle of the rivers -SMH 10th February,2010) is so right in his central point that only rain can solve the water shortages in the Murray Darling Basin. The Government buying back water licenses, when there is no water and no allocations, will do nothing to increase water when we are not receiving run-off generating rainfall. When we are receiving such rains, and water supplies are plentiful, the cancellation of these irrigation licenses will only restrict agricultural production so badly needed by a hungry world. We need to remember Dorothea Mackellar's line "droughts and flooding rains" to which we could add "and not much in the middle". The key characteristic of Australia's climate is massive rainfall variability.
Under these highly variable conditions there is something we can do to improve water supplies in dry periods. We need more dams to conserve surplus water in very wet conditions. These can also play a part in flood mitigation. Storages need to be deep so as to minimise evaporation losses - valleys in hilly country are best. The diversion of surplus flows from coastal flowing rivers (eg NSW North Coast), with damming and tunnelling, would not only mitigate floods, but also provide water for food production
The South Australian's claim that the dreadful condition of the Lower Lakes (Alexandrina and Albert) is due to extractions and lack of fresh water from upstream. No mention of the fact that under natural conditions the Lower Lakes were sometimes salty and sometimes fresh depending on fresh water flows, or lack of them, from upstream in Victoria, NSW, and Queensland. No mention of the impact of the building of "The Barrages" at the mouth of the lakes which converted the Lakes to all times fresh with the expectation that there would always be sufficient fresh water flows from upstream.
Under natural conditions with no dams in the Upper Murray catchment and no Snowy diversions, with the minimal run-off of the recent drought years, the Murray would have stopped flowing some three years ago. Salt water would have entered the Lakes and the lower reaches of the river itself as it always did under such dry conditions in the past, prior to the building of the Barrages. So it can be argued that the dire condition of the Lakes is largely a man-made problem.It is only the water stored in the Upper Murray dams, the Snowy diversions and restrictions on irrigation that have enabled the Murray to maintain any flow at all.
Water Management in the Murray Darling Basin
Paul Myers (Only rain can solve riddle of the rivers -SMH 10th February,2010) is so right in his central point that only rain can solve the water shortages in the Murray Darling Basin. The Government buying back water licenses, when there is no water and no allocations, will do nothing to increase water when we are not receiving run-off generating rainfall. When we are receiving such rains, and water supplies are plentiful, the cancellation of these irrigation licenses will only restrict agricultural production so badly needed by a hungry world. We need to remember Dorothea Mackellar's line "droughts and flooding rains" to which we could add "and not much in the middle". The key characteristic of Australia's climate is massive rainfall variability.
Under these highly variable conditions there is something we can do to improve water supplies in dry periods. We need more dams to conserve surplus water in very wet conditions. These can also play a part in flood mitigation. Storages need to be deep so as to minimise evaporation losses - valleys in hilly country are best. The diversion of surplus flows from coastal flowing rivers (eg NSW North Coast), with damming and tunnelling, would not only mitigate floods, but also provide water for food production
The South Australian's claim that the dreadful condition of the Lower Lakes (Alexandrina and Albert) is due to extractions and lack of fresh water from upstream. No mention of the fact that under natural conditions the Lower Lakes were sometimes salty and sometimes fresh depending on fresh water flows, or lack of them, from upstream in Victoria, NSW, and Queensland. No mention of the impact of the building of "The Barrages" at the mouth of the lakes which converted the Lakes to all times fresh with the expectation that there would always be sufficient fresh water flows from upstream.
Under natural conditions with no dams in the Upper Murray catchment and no Snowy diversions, with the minimal run-off of the recent drought years, the Murray would have stopped flowing some three years ago. Salt water would have entered the Lakes and the lower reaches of the river itself as it always did under such dry conditions in the past, prior to the building of the Barrages. So it can be argued that the dire condition of the Lakes is largely a man-made problem.It is only the water stored in the Upper Murray dams, the Snowy diversions and restrictions on irrigation that have enabled the Murray to maintain any flow at all.
04 February, 2010
Darling River-Flow Variability and Magnitude
At Christmas time the Darling River at Bourke had ceased to flow and real fears were held for the towns future water supply. Irrigation was out of the question. Then it poured across north/western NSW as the remnants of a cyclone made their way across the continent from the n/w of Western Australia.
The Darling River peaked at Bourke on 23rd January at major flood level height of 10.779 metres with a daily flow level of 47,219 megalitres.
Between the 28th December and the 4th February a total of 1,361,842 megalitres of water (almost three Sydney Harbours) flowed past Bourke. It is estimated that 30,000 megalitres was extracted to fields and off-river storage, by all irrigators from Brewarrina to Louth-2.2% of the total flow.
The water kept in the river as a consequence of the Governments (Federal and State) purchase of Toorale Station and its irrigation licenses was approximately 10,000 megalitres-0.73% of the flow. A pretty poor return on $23.75m!!
The river continues to carry a good flow.
Most of the water flowing past Bourke will be stored in the Menindee Lakes Storage Scheme where approximately 50% will evaporate.
As we Australians seek a better balance between socio-economic and environmental needs these sort of numbers and the fact that such events are not atypical, needs to be more widely understood.
The Darling River peaked at Bourke on 23rd January at major flood level height of 10.779 metres with a daily flow level of 47,219 megalitres.
Between the 28th December and the 4th February a total of 1,361,842 megalitres of water (almost three Sydney Harbours) flowed past Bourke. It is estimated that 30,000 megalitres was extracted to fields and off-river storage, by all irrigators from Brewarrina to Louth-2.2% of the total flow.
The water kept in the river as a consequence of the Governments (Federal and State) purchase of Toorale Station and its irrigation licenses was approximately 10,000 megalitres-0.73% of the flow. A pretty poor return on $23.75m!!
The river continues to carry a good flow.
Most of the water flowing past Bourke will be stored in the Menindee Lakes Storage Scheme where approximately 50% will evaporate.
As we Australians seek a better balance between socio-economic and environmental needs these sort of numbers and the fact that such events are not atypical, needs to be more widely understood.
03 February, 2010
Toorale Water Claims
The Federal Government is now claiming (Penny Wong ABC AM 03/02/10) up to 20,000 megalitres of water returned to the Darling River as a consequence of the Government's purchase of Bourke's iconic Toorale Station. A few weeks ago they claimed 11,000 megalitres, so presumably this new figure is additional?
The irrigation water storage on Toorale (Ross' Billabong) is estimated to hold approximately 10,000 megalitres and this is the only irrigation storage on the Station and apart from any water that may have gone direct on to irrigation fields, this is the maximum amount that can be claimed as being "returned to the Darling" from the current event. Water for this storage can be pumped from the Darling or diverted from the Warrego.
The Warrego River, which is mostly not flowing and is only a shallow gutter, runs through the property from north to south. It has five dams on it, all of which have two four foot diameter pipes (and gates) in the bed of the river. These allow smaller flows to pass through to the Darling. They are/were closed towards the end of a flow so as to retain water for livestock and domestic purposes,both for Toorale and neighbours, not for irrigation.
When there is too much Warrego water for the pipes to carry the river spills out to the west and runs down a natural flood plain, flooding over 20,000 acres before entering the Darling downstream of the main Warrego/Darling junction.
The original dams on the Warrego were built in the late 1890's by the legendary Sir Samuel McCaughey and apart from providing livestock and domestic water storages, one was designed to push smaller flows out on to the western flood plain where the water stimulates the most prolific growth of natural pasture, ideal for livestock fattening.
The very reasonable requirement of the NSW Government, in the second half of last century, to place the pipes in the bed of the river and allow smaller flows to pass through to the Darling, effectively means that natural conditions have been replicated. If there is too much water for the open pipes to carry the river would have spilled to the west anyway.
Thus, the Government cannot claim any additional "savings" as a consequence of the purchase of the irrigation licenses other than the water which could be stored for irrigation purposes in Ross' Billabong-10,000 megalitres.
The conversion of the whole property to a National Park has taken Bourke's most productive station out of production with all of the harmful impact this has on the Bourke economy and the local Mayor's call for the property to again be used as a grazing enterprise should be heeded. Toorale used to pay 10% of Bourke's total Shire rates, now it pays nothing.
The only environmental "benefit" that can be claimed as a consequence of the two Governments(Federal and State) purchase of Toorale, as demonstrated by the current flow event in the Warrego and the Darling, is the aforementioned 10,000 megalitres.Since the Ist January when the Darling commenced to flow again at Louth some 1,163,964 megalitres has flowed past Louth. An investment of $23.75m. for 0.86% of the flow (with plenty more to come)doesn't sound like good economics to me. Particularly when you consider that most of the water flowing past will be diverted in to the Menindee Lakes Storage Scheme where around 50% of it will evaporate.
David Boyd
03.02.10
The irrigation water storage on Toorale (Ross' Billabong) is estimated to hold approximately 10,000 megalitres and this is the only irrigation storage on the Station and apart from any water that may have gone direct on to irrigation fields, this is the maximum amount that can be claimed as being "returned to the Darling" from the current event. Water for this storage can be pumped from the Darling or diverted from the Warrego.
The Warrego River, which is mostly not flowing and is only a shallow gutter, runs through the property from north to south. It has five dams on it, all of which have two four foot diameter pipes (and gates) in the bed of the river. These allow smaller flows to pass through to the Darling. They are/were closed towards the end of a flow so as to retain water for livestock and domestic purposes,both for Toorale and neighbours, not for irrigation.
When there is too much Warrego water for the pipes to carry the river spills out to the west and runs down a natural flood plain, flooding over 20,000 acres before entering the Darling downstream of the main Warrego/Darling junction.
The original dams on the Warrego were built in the late 1890's by the legendary Sir Samuel McCaughey and apart from providing livestock and domestic water storages, one was designed to push smaller flows out on to the western flood plain where the water stimulates the most prolific growth of natural pasture, ideal for livestock fattening.
The very reasonable requirement of the NSW Government, in the second half of last century, to place the pipes in the bed of the river and allow smaller flows to pass through to the Darling, effectively means that natural conditions have been replicated. If there is too much water for the open pipes to carry the river would have spilled to the west anyway.
Thus, the Government cannot claim any additional "savings" as a consequence of the purchase of the irrigation licenses other than the water which could be stored for irrigation purposes in Ross' Billabong-10,000 megalitres.
The conversion of the whole property to a National Park has taken Bourke's most productive station out of production with all of the harmful impact this has on the Bourke economy and the local Mayor's call for the property to again be used as a grazing enterprise should be heeded. Toorale used to pay 10% of Bourke's total Shire rates, now it pays nothing.
The only environmental "benefit" that can be claimed as a consequence of the two Governments(Federal and State) purchase of Toorale, as demonstrated by the current flow event in the Warrego and the Darling, is the aforementioned 10,000 megalitres.Since the Ist January when the Darling commenced to flow again at Louth some 1,163,964 megalitres has flowed past Louth. An investment of $23.75m. for 0.86% of the flow (with plenty more to come)doesn't sound like good economics to me. Particularly when you consider that most of the water flowing past will be diverted in to the Menindee Lakes Storage Scheme where around 50% of it will evaporate.
David Boyd
03.02.10
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