Since the 1900′s there has been even more extraction of water. The hydrologists tell me the Lakes would become hypersaline if the barrages were removed now

Paul

Before the barrages, Mulloway (aka jewfish or butterfish) came into the lakes and a thriving fishery in the towns of Milang and Goolwa. Mulloway are an estuarine species. So ‘the always been freshwater’ theme is just incorrect.

Just check the history. It’s all there. The National Library of Australia has it all scanned in black and white. http://trove.nla.gov.au/

And these newspaper articles and reports from the 1900′s are not behind a ‘paywall’ they are free.

It is incorrect to state that salt levels and Adelaide water supply quality will depend on 3,500 GL of end of system flows. The water quality in the actual river and the water supply offtakes at Mannum during 2010 were quite adequate with only the MDBA specified dilution flow of about 350 GL into the lower lakes. The only problem was that the massive evaporation of 1.2 m of water per year from the shallow lakes with an average depth of 2.5 m lowered the lake levels to below sea level and increased salinity levels below Mannum. The problem with salt levels was therefore the evaporation from the lakes and not the amount of flows out of the Murray mouth.

Salt levels in the River Murray would be fine above a new lock at Wellington, a dilution flow of 350 GL and the barrages allowing sea water in at times of low flows to make up for evaporation from Lake surfaces.

NSW Irrigators Council created an impact calculator (http://bit.ly/r33bMz) that simply analysed existing data sets based on megalitres cut (input) to determined jobs and economic productivity lost (output). The datasets are not new – they were fully published prior to the Guide. The analysis of the datasets is contained within the calculator for all to see, comment on and criticise – there has been none of the latter (to date).

It is free to use for anyone on any side of this debate.

Andrew Gregson
Chief Executive Officer
NSW Irrigators Council

http://joannenova.com.au/2011/05/climate-commission-report-debunked/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+JoNova+%28JoNova%29&utm_content=Google+Feedfetcher

Btw, you missed the insurance industry in on this scam. My goodness, I bet KAOS organising meetings are, well, chaos…

While this process occurs naturally, changes to the hydrology of inland rivers and wetlands have contributed to the accumulation of these sediments in some areas. If left undisturbed and covered with water, sulfidic sediments pose little threat. When exposed to oxygen, such as under drought conditions, chemical reactions may lead to the generation of sulfuric acid. When these sulfuric sediments are re-wetted and the amount of sulfuric acid produced exceeds the buffering capacity of the system, there is a risk that sulfuric acid may be released into the water, adversely affecting the health of wetlands and/or rivers.

Other risks associated with acid sulfate soils include mobilisation of heavy metals, decrease in oxygen in the water column, and production of noxious gases. These processes can lead to substantial environmental damage and serious impacts on water supplies and human health.

MDB Annual report 2008-9

key points- keep oxygen out, achievable with seawater
– “Acid sulfate soils form naturally when sulfate-rich water (e.g. saline groundwater, or sea water) mixes with sediments containing iron oxides and organic matter” ie formed as a result of seawater intrusion into the lower lakes inthe first place.

Yes the 3000GL will benefit assets upstream, but simple mathematics suggest 1000GL is used by the environment in this scenario. This 1000GL could conceivably be applied more efficiently to the environment. If keeping the Murray mouth open 90% of the time is paramount then some thought must go into the role of the barrages on that figure. Nature had done an amazing job all by itself prior to the barrages, perhaps close to 100% even.

We’ve just been through an unprecedented procession of low inflows to the Murray system, and the lowest 15year average on record, yet the mouth has been open close to the plans indictaed 64% model during this period. I reiterate during the lowest set of years in over a hundred years of records.

If we look at the years from the early 80′s(from which I take as near full development of the MDB) the mouth has been closed 7 or 8 years out of 30. Open 75%, inclusive of unprecedented record drought years.

If I remeber rightly the science of a few years ago (circa 2006) indicated 1GL/day was required to keep the mouth open. Taken in conjunction with Jennie Fluin’s paper:

“These data suggest that the primary role of River Murray discharge was to:
- keep the Murray Mouth open and allow sea water into The Coorong
- generate estuarine conditions at the northern end of the North Lagoon during high
flow periods
- facilitate circulation and mixing in the North Lagoon such that salinities were
maintained at or below those of seawater.”

One would have to ask the question what the benefit of 12500GL over 5100GL outflows really is. Especially if the 1000GL or so total Murray inflow of 2006/7 and 2200GL in 2007/8 is appraised. A period when 3000GL + of NSW general security water alone had 0% allocation. Or another way, after filling nearly all onfarm storages on the Darling, filling the Menindee lakes, filling the Murrumbidgee storages as well as Lake Hume let alone the Lower lakes themselves- all from low bases- water is still flowing out to sea. Yes it is a wet year, and that is what our irrigation storage and infrastructure is about. Harnessing the wet and spreading the water to the dry.
What we tend to forget is that while there is water in storage in those dry years, under pre-development conditions that wet years water would have been and gone.

Cheers

cheers

I agree that there are no easy solutions, but I am sure if anyone can find a workable way through this challenge, it is Australian farmers, scientists and people.

I was pleased to see your comment about this issue having implications beyond the borders of Australia. While the world can probably do without our lower priced wine, many people outside Australia also rely on staples produced within the system. We need to think about how to continue to boost food production with less water. We don’t want to create other problems by solving this one.

In response to your comment “Now we find the ground rules have changed, and feeling dispensable is not gratifying to say the least”, I could not agree more. Most farmers are working within the rules, work hard and take risks to produce food and support their families. It has been government policies that have created this mess, and as I said in the post, the whole of Australia has to take some responsibility to fix it. I would support measures to assist communities to work their way through these proposed changes. By the way, not all cuts will need to come from reduced allocations, and we all hope that much can be achieved to find more savings through water delivery efficiencies.

1, There are more profitable crops, but to grow them on the scale of even a 25% reduced cotton area will flood the Australian market, if not the world. I’ve met more the few brocolli farmers overseas who knew of a certain goondiwindi cottongrower who flooded the world market with brocolli. Neighbours here tried the onion market but it is who you know when it comes to marketing. No objections to further study, it would be a win on all counts to find such a crop.

2, different areas have different issues. While larger regional settings will prosper others won’t. Irrigation does not have a monopoly on the rural workforce, and I would wonder why other industries could not have established themselves concurrently with irrigation before now. Given the skillsets rising unemployment won’t be the spark for new businesses.

3, true australia will not want for food simply because the MDB’s supply falls. Unfortuately the same can’t be said for other countries that depend on imports. Whilst we don’t supply them all, our presence as an exporter helps keep prices affordable. Few countries have exportable surpluses. Despite our small overall production we are usually in the top 5 exporters.

4, Comments like cotton and rice shouldn’t be grown in Australia, and primitive or idiotic irrigators do little to support this statement. As an irrigator I didn’t set out to ruin the Murray, nor, I think, would any other irrigator. An allocation was decided decades ago and we’ve worked within those constraints since. Now we find the ground rules have changed, and feeling dispensable is not gratifying to say the least.

5, Hard to say, as the govt are purchasing actual entitlement, then by rights the water is not available to others except by sale. Govt has sold water back in the Gwydir Valley, so I have to say that makes a mockery of needing more buybacks in that valley.

6, This might be where I ask you what those economic and environmental costs would actually be? After all the long term average outflow is still supposed to be 5000GL+ each year

Cheers