Craig Knowles, chair of the Murray Darling Basin Authority, writes: Last week, we kicked off our first public meetings after the release of the draft basin plan. I say this because we have been consulting with communities, individuals and representative groups since February.
The formal part of the public consultation started in St. George, Queensland and Murray Bridge, South Australia. It was a great opportunity to get back-to-back perspectives from both ends of the basin. This week we met with communities in Shepparton and Griffith, and we have meetings in Deniliquin today. But it won’t stop there and throughout the rest of the 20 weeks of consultations on the draft plan, I will be meeting with more basin communities to hear their ideas, concerns and work towards getting the best starting point for water reform in the basin.
As we continue on the consultation process, I thought I would take the opportunity to address one of the concerns that has continually been raised — and that is how we came up with the proposed limits on water use. As anyone following the debate will no doubt know, we are proposing that 2750 gigalitres per year of water need to be returned to the environment. Already there have been significant efforts to recover water for the environment, which means there is 1468 GL/y left to be found by 2019 to meet this target.
But how did we get to the target of 2750 GL/y?
Well, working out an environmentally sustainable level of water use for a basin that is greater in size than the combined area of France and Germany is not an easy task. It is complex and challenging. It involves looking at a diverse range of environments, catchments and communities, which are all connected to one another.
There has been a long history to determining the environmental water needs of the basin, which dates back at least as far as the early 2000s when work first began on The Living Murray initiative. However, for the sake of brevity, I will just go back to a little over 12 months ago to the release of the Guide to the proposed Basin Plan which built upon much of this work.
When the guide was released in October last year, it suggested that between 3000 and 4000 GL/y of water needed to be returned to the environment. These numbers were based on a simple assessment that aimed at achieving a minimum of 60% of flows at the end of each of the major rivers in the Basin, in the expectation that this would be enough water to support the basin’s environmental values. Given the simplicity of the method, it was useful for an initial assessment but lacked the necessary rigour for the draft basin plan.
Instead for the draft plan we returned to a method that the MDBA has been developing since 2009. Called the “hydrological indicator site method”, it involves looking at the environmental water needs of sites ranging from large floodplain wetlands (such as Narran Lakes, Macquarie Marshes, Lower Murrumbidgee Floodplain, Barmah–Millewa Forests) to small points along the length of the basin’s river channels. For these selected sites, environmental objectives and water requirements have been identified. Together, these sites combine to build a picture of the environmental water requirements of the basin’s environment.
We have published a report that details the method in full, including the underpinning science, the environmental water requirements for each site and the expected environmental outcomes in each catchment. I commend to all those who are interested, to take the time to read this report. However, there are some key findings and approaches I would like to highlight.
While the guide looked at a range of 3000–4000 GL/y, for the purposes of the draft basin plan we have focused on the lower end of this range (based on socio-economic considerations). Using the hydrological indicator site method, our ecologists and hydrologists have been busy modelling the environmental outcomes that can be achieved with returning between 2400–3200 GL/y of water to the environment. And from the results, the starkest contrast between the three volumes modelled (2400 GL/y, 2800 GL/y and 3200 GL/y) is for sites downstream of Euston Weir on the Murray, such as Hattah Lakes, the Chowilla Floodplain and the Coorong.
At 2400 GL/y, it is unlikely that salinity targets at the Coorong and flow targets for river red gum forests at Hattah Lakes and Chowilla Floodplain will be met during drought conditions.
In comparison, returning either 2800 GL/y or 3200 GL/y to the environment has a marked improvement on both the ability to manage salinity in the Coorong and maintain the health of the lower floodplain forests on the River Murray. However, at 3200 GL/y, while there are some incremental improvements in environmental outcomes compared to 2800 GL/y, there are greater socio-economic impacts.
Significantly, under all scenarios, it is not possible to deliver water to meet the needs of higher floodplains in parts of the basin. This is due to operational and physical constraints in the system, such as those in place to avoid flooding private property. It is possible that some of these constraints could be overcome as part of the “rules review” to be carried out in coming years. In the meantime, by including these constraints in the modelling we can be certain the recovered water can be delivered.
Part of this modelling was a detailed analysis in the Condamine–Balonne and the northern basin (including investigating the environmental outcomes at Narran Lakes and the Balonne Floodplain). This information led to a 50 GL/y reduction in water recovery targets in the Condamine-Balonne. Based on these assessments, the Authority believes returning 2,750 GL/y to the environment will achieve sustainable levels of water use across the Basin and optimises economic, social and environmental outcomes.
A key component of the draft basin plan is the environmental watering plan. We have made a conscious decision, in line with feedback from stakeholders, not to specify when, where or how much environmental water is used. This allows both flexibility and local input into decisions on environmental water use. Instead, it outlines the environmental objectives, principles and processes that should be followed.
Throughout the development of the draft basin plan, we have had our science and socio-economic analyses independently peer reviewed. These reviews are all publically available and have been supportive of our methods and analysis. Contrary to reports otherwise, this includes the recent CSIRO-led review of the science, which is supportive of our approach and the underlying data and modelling.
Finally, I would encourage anyone interested in the draft basin plan to make sure you take the time to read our documentation and see firsthand what we are proposing and what we expect the outcomes to be. And having read our documents, join in the discussion over the 20 week consultation period. Because, in the end, this is just a draft Basin Plan and the proposals it contains are just that — proposals.
Murray Murmurings is back! Crikey’s environment blog Rooted is publishing a series of articles from different interested parties — farmers, lobby groups, environmentalists. Now the draft plan’s been finally released (head here for an overview of it), we’re doing it again. If you’d like to contribute your thoughts, please email ajamieson[at]crikey.com.au
4 Comments
Moderator: Please post this version instead.
Mr Knowles,
Why are the lower flood plains a higher priority than the higher flood plains to receive environmental flows? Why is “achieving a minimum of 60% of flows at the end of each of the major rivers in the Basin” the most desirable environmental outcome?
Your essay confirms the hold that the South Australian water mafia has over the whole MDBA plan. You don’t mention that this 60% target requires the filling of the artificial and highly inefficient freshwater lakes of South Australia (such as Lake Alexandrina).
You also don’t mention that the pursuit of this goal means that critically important wetlands such as the Wakool River basin (with its magnificent national park red gum forests and one of the most important Murray cod hatcheries….and actually the deepest river in the so called “Murray Valley” at its latitude) are being sacrificed by the MDBA under their “we must get water to South Australia” mantra.
Water that should flow down the Wakool river, as an example of one of many wetlands sacrificed under the MDBA’s lower murray holy grail, is instead diverted down the Murray and Edward rivers…..because the Wakool river is seen by the MDBA as a “poor regulator”. What this really means is that all the redgums, billabongs
and intermittent creeks along the Wakool consume quite a lot of water. The MDBA would rather deliver water to South Australia via rivers such as the Edward river and the Murray both of which have had most of their logs removed for paddle steamers and so now serve as a better “water supply canals” to serve South Australia, than more deserving rivers for environmental flows such as the Wakool.
The very idea that rivers are chosen for flows based on how much water runs out the end causes the MDBA to divert water away from the rivers that need water the most. The “naturalness” of rivers such as the Wakool, with all its logs intact, restricts the flow of the river and causes all the billabongs and anabranches to fill during periods of high flow…..becomes the reason the MDBA sees such a river as a “waste of water”.
Diverting water away from the Wakool River and down the Edwards river in October 2010 caused an artificial black water event that probably killed every Murray cod fo along a 200 kilometer length of the Wakool. [ See: http://www.abc.net.au/am/content/2010/s3038982.htm
PLEASE DON’T KILL THE WAKOOL RIVER WHILE YOU ARE SAVING THE MURRAY!
When the writer says ” there are greater socio-economic impacts.” read ” we are scared shitless the irrigator lobby will kick shit out of us in the media”.
requires the filling of the artificial and highly inefficient freshwater lakes of South Australia (such as Lake Alexandrina).
“Lake Alexandrina is the finest sheet of fresh water I ever saw. Indeed so formidable did it look, with a stiff wind blowing up quite a sufficient swell to make one seasick, that I could scarcely believe it to be fresh. Such is the fact however. It is forty or fifty miles long by twelve or fifteen wide and the shores around it receded into the dim distance until they become invisible, in the way which we are accustomed only with ideas of salt water. Supplied almost entirely by the Murray, the whole lake retains the muddy tinge of which I have spoken, and this sadly detracts from the otherwise beautiful appearances of this magnificent sheet of water.”
http://books.google.com.au/books?id=tsENAAAAQAAJ&pg=PA45&redir_esc=y
Edward Wilson visiting in 1850s
Defiantly not artificial
Timothy,
If it’s not artificial then why are the barrages necessary to keep the ocean out? When Edward Wilson visited in the 1850′s it was probably a year much like 2012. Absolutely, Lake Alexandrina can be a fine sheet of freshwater…..but it is meant to be a dynamic estuarine environment, sometimes fresh, sometimes saline, depending on the flow of the river.