Monday, November 20, 2006

Snow job on the Snowy River

As the Murray Basin gets another “summit” for it's troubles it is timely to take a good hard look at the facts behind the last river to get the “can do” swagger from our politicians and environmental saviours. In October 2000 the Feds, NSW and Victorian governments gave us another “milestone” in the great pantheon of environmental achievements. They agreed to return 21 per cent of the Snowy River’s water that has hitherto been captured in the dam system and sent down to the Murray irrigators.

The hype merchants and word molesters were out in force. They had “saved an Aussie icon” and “restored the mighty river to its former glory”. There was no room at all for the fact that these custodians of the public good had just seriously impaired the contributive value and efficiency of a public asset, the dam system and related power generating capacity.

But that is only small beer compared to the character, scale and extent of the gross misrepresentation of facts that had been introduced into the policy process, without any apparent challenge by the professional officers involved, leading up to this decision.

A good grasp of the kind of arguments put by the self-appointed saviours of the Snowy River, prepared by East Gippsland Independent State MLA, Craig Ingram, can be seen here. If this MP has made similar representations to the Victorian Parliament then there are grounds to investigate whether he has engaged in grossly misleading and deceptive conduct.
He informed us that:

"The value of the Snowy River to the Australian people is beyond calculation. Right now, this national icon lies at death's door. The once mighty Snowy River has been reduced to a series of small, stagnant pools, choked with weeds and sand. Seawater is intruding upstream and native fish are fast disappearing".

Note the clear implication that river flow is negligible and that this condition is present over the entire length of the river system. This perception was reinforced under the heading “a matter of equity” with the claim that “Australians are asking for 28% of the original flow to be returned to the Snowy River”. And who, one may ask, could possibly argue against an apparent restoration of a river from zero% to 28% of its former flow?

But let’s put this into perspective. This 28% amounts to about 330,000 megalitres or 1.3 times the total volume used each year by the 1.5 million residents of greater Brisbane. It was followed by the claim that, “the water needed for the Snowy can come from efficiency savings in irrigation”.

They quoted Professor John Lovering, former Chairman of the Murray Darling Basin Commission, as saying, “just a 10% improvement in irrigation and farm management practices could deliver one million megalitres of extra water to irrigators”. And then implied that a simple, unstated, back-door, tax-in-kind, of 33% of the farmer's gross, hard won, efficiency gains, on top of all their existing tax obligations, was all that was needed to fix this “matter of equity”.

No one asked if any other segment of the broader community was being asked to hand over a full third of their gross efficiency gains over more than the next decade. Per capita productivity gains in Australia are generally in the order of 1% per annum and those gains are already taxed at between 30% and 45%. But the parties to this water agreement, both Liberal and Labor, thought nothing of taking the first 33% of farmers efficiency gains as water tax, oblivious to the fact that the farmers would subsequently be taxed another 30% to 45% on the remainder. The effective tax on these farmers productivity gains would be 55% to 60%.

In blissful ignorance, it was such a simple, seductive concept that it was easily taken up by otherwise intelligent departmental officers, who lacked either the time or inclination to think the matter through.

The Alliance lists as references:

  • 1994 scoping report commissioned by NSW and Victorian Governments. Recognises 28 per cent of the Snowy's original flow is needed to reinstate the ecological function of the river;
  • 1996 expert panel of scientists conclude that insufficient water is released from Jindabyne Dam to maintain a healthy ecosystem. They recommended 28%;
  • 1998 Scientific Reference Panel of the Snowy Water Inquiry conducted by NSW and Victorian Governments supports a minimum of 28%.

The ACT Environment Commission also gets into the act with the narrow perspective of the Snowy River Shire when it claims, “The scheme diverted close to 99%, or 520 gigalitres each year, of the Snowy River flow into the Murrumbidgee and Murray River system. This left the Snowy River with only 1%, or nine gigalitres, of its average annual flow. A decision in 2002 saw this environmental flow increased to 38 gigalitres each year, or 6 per cent of the total flow.”

But it then includes a very important rider, stating, “No estimate of the volume of water that escapes the Shire in the various river systems, where that water is not captured by the scheme, is available”.

You see, all the claims about absent flows, and so on, have been in relation to the minor portion of the river system immediately below the dams. And both the public, and the policy process, has been encouraged to assume that this applies to the entire river system. But as each additional tributary joins the river on its way to the sea the more “healthy” the river becomes.

Indeed, the East Gippsland Catchment Management Authority provides the first glimmer of evidence that the Snowy system is not quite as bad as it has been made out to be. It has a map showing entirely unmodified tributaries (listed for their heritage values) and a photo of what looks like a very healthy river.

It is not until we go to the Australian Natural Resource Atlas that we get closer to the real story on the Snowy River.

Total catchment area = 1,589,600 hectares

NSW catchment area = 894,000 ha

Victoria catchment area = 685,600 ha

NSW mean annual runoff = 1,317,000 megalitres of which 513,000Ml is captured in dams.

Victoria mean annual runoff = 863,000Ml plus 804,000Ml from NSW.

And this tells us that about 1,664,000 megalitres out of total catchment runoff of 2.18 million still makes it to the sea at Marlo. So we have a river system which has numerous tributaries that still exhibit zero disturbance in normal flows and allow the lower river to still deliver 76.3 per cent of total runoff into the sea.

The claimed requirement for another 330,000Ml, deemed by the above mentioned “expert panels” as the minimum required to restore the ecological function of the river, would send 91.5 per cent (1.99 million Ml) of total runoff into the sea.

Note that there is some discrepancy in the Alliance's maths. If 330,000Ml is 28 per cent of flow then total flow would only be 1.18 million Ml not the 1.317 million Ml reported by ANRA as the NSW share of the runoff. What we do know with absolute certainty is that no mandate would have been given by the public to undermine the efficiency of expensive infrastructure for the dubious benefits of lifting river flow from 76.3% to 91.5%.

But wait, there is more. The Victorian part of the catchment is still largely timbered so we can assume that the runoff volumes from the Victorian portion are close to the original pre-settlement volumes. The same cannot be said about the NSW portion where, outside of the National Parks and reserves, extensive clearing has increased the runoff volume from pre-settlement volumes.

The Australian Natural Resource Atlas has good, but apparently limited access, data on the extent and type of original vegetation and the extent of subsequent clearing. An exact area is not available but by visual estimate about 66% of this part of the catchment has been cleared. And from this we can make a reasonable "guestimate" at the change in runoff volumes since settlement. (Link here. If you can't access this then please follow the links here to find out why.)

We also know the mean annual rainfall at Bombala is 645mm which is quite evenly distributed throughout the year. This even distribution is also present at Nimmitabel with mean annual rainfall of 690mm. And from the work on 21 Victorian catchments by Holmes and Sinclair in 1986, as reported in Vertessy et al, 1998, “Predicting water yield from Mountain Ash catchments”, we can determine the changes in yield with some accuracy.

Where there is an annual rainfall of 700mm a forest will use 650mm while 50mm is runoff. If you clear that forest to pasture and, assuming it is not overgrazed, it will use 545mm of rain with 155mm of runoff, an increase in yield of 210 per cent.

So when we look at the catchment below the dams and above the state border we find 1/3rd uncleared land that produces 100 per cent of presettlement water yield and 2/3rds cleared land that produces 310 per cent of pre-settlement water yield. And this means that the current runoff of 804,000Ml represents (1x 0.333 + 3.1 x 0.666 = 2.4) 2.4 times the original pre-settlement flows.

Hence, the total pre-settlement flow from both cleared and uncleared land was 335,000Ml while the cleared land now delivers an additional 469,000Ml to the Victorian part of the river.

This tells us that the original pre-settlement flows at the mouth of the Snowy River consisted of;

863,000Ml from the Victorian portion;

335,000Ml from the NSW portion below the dams; and

513,000Ml from above the dams,

for a total flow of 1.711 million Ml.

And that means that the current mean annual flow of 1.644 million Ml is actually 96 per cent of the pre-settlement flow. In effect, all but 44,000Ml of the 513,000Ml that is diverted from the Snowy to the Murray is already compensated for by the increased runoff from clearing in the NSW portion.

But the downstream observers in Victoria only have visual and anecdotal references to river flows that have occurred after the upstream clearing activity has increased flows. And it is this man-made increase in river flows that they are now seeking to convert to some sort of baseline for an environmental duty of care to minimise harm. But if they succeed in getting the existing agreement implemented they will lock in an entirely unwarranted ecological surplus at the expense of the Murray system and the communities that depend on it.

The facts are that the current 4 per cent reduction in river flows is almost statistically irrelevant in terms of the normal range of variation in rainfall and runoff. For example, the 1st decile event for Bombala is only 457mm (71% of mean) and the 9th decile event is 866mm (134% of mean) for a natural range of 66 per cent of mean.

This is not to say that the 30 to 40km of river below the dam is not significantly diminished, it obviously is. But pouring $50 million worth of valuable water into the ocean is a very silly, indeed, incompetent way of fixing the problem. There is a much better way - based on the fact that the one type of water use that is most suited to recycling is water used for environmental flows.

The Snowy River itself does a great deal to assist in the recycling of its environmental flows. It traces a large, 95km, bend in the section concerned that ends only 27km away from where it starts. So the construction of a short pipeline and pumping system would enable the release of just a single day’s worth of environmental flow which could then be pumped back to the starting point (recycled) to do the same job each day for the next 364 days each year.

This would take place before the steep drop onto the Victorian lowlands and the countryside that the pipeline would need to cross is already cleared with comparatively mild undulation that is well suited to pumping and syphoning.

The key to the feasibility of this sort of recycling of environmental flows is; can we pump a megalitre of water along a 27km pipe with modest head for less than the price that a farmer would pay for the same megalitre?

Clearly, the answer is an unambiguous “Yes”.

Adelaide pumps its water 170km from the Murray River, and over a hill, presumably at an acceptable wholesale price.

Farmers in the Brisbane Valley are eager to pay for recycled Brisbane sewerage that will be pumped more than 60km.

The plan to reintroduce recycled water into Wivenhoe Dam will involve a lift of more than 100 metres and more than 40km of pipeline and be reintroduced to the urban water system at a profitable margin on a wholesale price of $170 per Ml.

So even if there was a sound case for restoring flows to the Snowy River then taking good water out of the dams is not the best option. The Greens’ target of 330,000Ml in water savings could be ploughed back into more production that will inject $132 million into towns on the Murray each year. A modest pumping load of 100Ml a day would deliver 36,500Ml of river flow to the actual section of river that needs it while leaving 36,400Ml for farmers to add $15 million worth of crop value to the remainder.

For the moment, the most inefficient water users, and those most reluctant to adopt new ideas, technology and innovations, are the Green movement and their captive departmental minions. Unlike sewerage or storm water recycling, water that is released for environmental flows needs no expensive processing to enable it to be used again, and again. And this capacity for multiple recycling gives it an entire order of magnitude greater priority than all other water efficiency options. We all need to get a lot smarter with our use of water but our self appointed environmental guardians have a lot further to go than anyone else.

More importantly, neither the federal government, nor any of the state governments would be complying with our well defined principles of "proper exercise of power" if they continue to try to develop catchment wide water allocation policies without taking the highly relevant factor of clearing induced changes in water yield since settlement into account.

To continue to do so in the face of such overwhelming scientific evidence would not only be grossly negligent but may also constitute criminal conspiracy. It has to stop.

Ian Mott

Copyright 20/11/2006

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