Jennifer Marohasy

a forum for the discussion of issues concerning the natural environment

Murray River

Some Time by the Murray River

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I have enjoyed spending the last couple of weeks living on a bank of the Murray River just upstream of Barham.

The bird life is especially amazing with wood ducks in the river, white ibis, sulphur-crested cockatoos and galahs on the lawn, superb blue wrens in the bush outside my office window, swift parrots in the red gums and very black ravens drinking out of the bird bath.

I saw a lot of black swans when I visited the salt evaporation ponds at Wakool. I saw a shag in the Gunbower Forest. There were two pelicans at the Toorrumbarry Weir.

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Just downstream of the Toorumbarry Weir, November 6, 2007

I have started most days with a large glass of Murray River water and on the best days finish with a swim in the river.

While many of the forests, tributaries and anabranches in this Murray Valley section of the long Murray River are suffering from a lack of water, the river itself is running strongly with releases from Hume Dam at the top of the system destined for South Australia at the other end.

Anyway, tomorrow morning I’m off to Sydney.

Thanks Faye and Ken for your hospitality! And Daryl, I took photographs at Riverdale this morning which I will post at this blog in the next week or two with comment from the MDBC report.

Murray River Tributary Reduced to Billabongs

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While the Murray River is flowing strongly despite the drought, many of its tributaries are drying up.

Yesterday I visited the Wakool River with Wakool Landholders Association Chairman John Lolicato.

He showed me a spot downstream of Gee Gee bridge where there is still water in deep holes. A bit upstream the river has been reduced to billabongs and further upstream in Possum forest some of the billabongs have dried up.

John Upstream Gee Gee Bridge (copy Wakool River 026).jpg
Downstream of Gee Gee bridge

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A billabong that was Wakool river

John has moved some Murray Cod from drying billabongs to larger water holes.

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John looking for some water and stranded fish

Also yesterday, the NSW Minister for Climate Change, Environment and Water Phil Koperberg announced that a pulse of water would be released into the Wakool River to provide stock and domestic water and environmental benefits.

Mr Koperberg acknowledged that the Wakool River had not had flows for months due to the severe and extended drought.

“The diversion of water into these systems will provide landholders with access to stock and domestic water for the first time in months, help improve water quality and provide significant environmental benefits to stressed populations of native fish and other aquatic species,” he said.

“The water cannot be used for irrigation and additional deliveries for irrigation are not viable as they would exacerbate additional water losses that cannot be supported.”

After the ‘Top Island’ Fire in the Barmah Red Gum Forest

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Aborigines managed much of the Australian landscape with fire. This management strategy favoured fire tolerant and fire resistant species – perhaps why gum trees dominate so much of the Australian landscape. But river red gums, Eucalyptus camaldulensis ssp., unlike most gum trees, are not particularly fire tolerant.

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A boat on the Murray River in the Barmah Forest. Photograph taken last Tuesday.*

The timber cutters and cattlemen who live and work along the middle Murray (river) have gone to great lengths to keep fuel-loads in red gum forests low through controlled grazing and the collection of firewood. This, combined with a network of rural fire fighting brigades, has made it possible to stomp out fires started from lightening strikes or camp fires.

This may explain why some foresters and aboriginal elders call river red gums ‘white fellas’ weed’ and why areas which were once open woodland are now covered in dense red gum forests including at Barmah.

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This area in Barmah Forest was once known as Duck Hole Plains

But the situation is changing. The Victorian Environmental Assessment Council (VEAC) wants more wood and grass on the forest floor apparently to increase biodiversity. This means higher fuel loads and according to some white fellas** the forests will ultimately be severely degraded by uncontrolled and uncontrollable feral fires.

A wildfire in the Barmah Forest, in an area known as Top Island, burnt out 800 hectares last October.

Barmah Fire blog (Copy Redgum 026).jpg
Burnt forest at Top Island in October 2006, photograph taken Tuesday November 6, 2007.

Old habitat trees are apparently the first to go when a hot wildfire burns through red gum forest. Last week the Barmah woodcutters showed me how the old trees ‘burnt like chimneys’ from the inside – out.

Parts of ‘Top Island’ look like they are regenerating. But I’m told that the green coppice growth will eventually fall off – that these fire-damaged trees will never develop as habitat trees. Habitat trees have hollows for wildlife.

Barmah Fire Regrowth blog (Copy Redgum 028).jpg
Coppice and a burnt-out old habitat tree.

Where the forest has been completely burnt, for example after the sand-spit fire of the late 1960s, and where there has been no management, the red gum regrowth can be very dense.

Barmah Sandspit fire growth (copy Redgum 072).jpg
Regrowth from the 1968 Sand-spit fire, Photograph taken November 6, 2007.

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* All the photographs in this blog post were taken in Barmah forest last Tuesday – on Melbourne cup day.
** I use the term ‘white fellas’ to refer to the guardians of traditional European knowledge in the Barmah forest.

Thinning Red Gum Forests at Koondrook

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I’ve been staying with friends who live on the Murray River in western New South Wales and I’ve seen a lot of river red gums – beautiful old habitat trees, thickets of young saplings, healthy forests, water-stressed forests, bushfire- damaged forests, trees ready to be made into railway sleepers, others into veneer.

Many of the forests are suffering from the drought. While some activists claim the solution is more environmental flow water allocation, this is unlikely until the drought breaks. In the meantime some believe some forests can be ‘drought proofed’ through thinning.

In the following picture the density of red gums has been reduced through a thinning operation on private land. On the other side of the fenceline the trees have not been thinned.

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Koondrook Forest, 3rd November 2007

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Habitat tree clearly marked for saving.

A recent Victorian Environmental Advisory Council (VEAC) report proposes that more red gum forest along the Murray River be converted to national park – this time about 100,000 hectares.

The report states that many forests are severely stressed and that there is evidence that without improved environmental flows many of these forests may be lost over time.

But locking them up as national parks may only exacerbate the situation. Indeed what many forests appear to need now is thinning, to reduce competition for water between trees.

Some of the forests along the Murray River in the best condition right now are the more actively managed forests – with lower tree densities from thinning as well as forests that received environmental flow allocations in the last few years.

Still Water in the Murray River

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Last week I drove from Brisbane (south eastern Queensland) to Barham on the Murray River.

Listening to the news in Brisbane I was getting the impression the Murray River was nearly empty of water.

In fact there is still a lot of water in the river but the Hume and Dartmouth dams are very low. Also, some of the tributories of the river are being shut-off with cod dying in the ‘shrinking’ billabongs. And many river red gums on the flood plains are looking very stressed from the drought.

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But as this picture shows, the river itself is still magnificent and the red gums along the river beautiful.

Remove the Barrages for the Coorong: A Note from Rojo

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Hello Jennifer,

I have been a reader and minor contributor at your blog over the last few months.

A few weeks ago I was discussing the Coorong with another commentator in relation to the Prime Minister’s new $10 billion National Water Security Plan in particular the hyper-salinity aspect.

With all the talk of the Murray “dying” I had thought the hyper-salinity was due to lower flow from the Murray River, the direct implication being less dilution of the Coorong as well as not being able to keep the mouth open.

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As an irrigation farmer it is not pleasant to be accused of being partially responsible for destroying the Coorong.

Having been across the barrages and seeing the Coorong first hand late last year, meeting affected stakeholders and talking to South Australian government officials, I couldn’t help but feel it is the right thing to send the Coorong more water and thus that I should support the $10billion plan in its aim to buy back water for the river.

However, if my interpretation of this report ‘A Paleaecological Assessment of Water Quality Changes in the Coorong, South Australia’ is correct, the actual water from the Murray River has had no noticeable influence on the Coorong.

In fact, according to the report:

“Before European settlement the northern lagoon of the Coorong was dominated by tidal input of marine water. Marine flushing also strongly influenced the southern lagoon but less
frequently or to a lesser extent.

At no time in the 300 years before European settlement has the Coorong been noticeably influenced by flows from the River Murray.

The northern end of the southern lagoon occasionally experienced hypersaline conditions in the 300 years before European settlement. Elsewhere in the Coorong, the salinity was typically at, or below, 35,000 mg/L. In the southern lagoon the presence of diatom and ostracod taxa preferring salinity levels ~ 5000 mg/L suggests regular freshwater input. This source is likely to have been from the south-east.” [end of quote]

The report also states that “the extended presence of marine diatom taxa in Lake Alexandrina suggests the tidal prism regularly extended into Lake Alexandrina throughout the last 6000 years”, which I take to mean long periods of low flow where the mouth evidently did not close but rather was flushed by the sea.

What few people now realize is that there are barrages, construction completed in 1940, across each of the five channels connecting the lakes with the Coorong. These barrages restrict tidal flow into the lakes and stop freshwater flowing out of the Murray River’s mouth.

So effectively we might spend billions taking water from upstream irrigators and in the process displace jobs/communities and achieve nothing for the Coorong.

I do realise there are other “iconic” sites on the Murray that will benefit from more water, but they benefit already from the environmental nature of water deliveries prior to extraction, and don’t require 1000GL of fresh water evaporation from the lakes in low availability scenarios.

I now wonder if the most natural thing we can do for the Coorong is to remove the barrages and allow tidal action to do it’s business in particular flushing the Coorong. If this study by Adelaide University is correct the fresh water from the Murray River is not what the Coorong needs. It needs to be flushed by the ocean and this would be facilitated by the removal of the barrages.

Using stored fresh water from upstream to keep the mouth of the Murray River open, as currently advocated by various environment groups and the federal government shouldn’t really be an option.

There is currently a proposal to build a weir on the river at Wellington which is upstream of the lakes.

Irrigators currently dependent on the Lakes would have to be supplied from water upstream of this proposed new weir, much to their benefit by getting better quality water. Funding under the new $10 billion water plan could allow this to happen.

If we don’t get significant inflows the weir at Wellington will be built, the lake levels will fall and the irrigators won’t be irrigating anyway. But the situation at the Coorong will not improve unless the barrages are removed or opened.

If we do get substantial inflows, what was the problem again?

Cheers
Rojo