Thursday, January 07, 2010

Water Wars - the Darling floods

floods Nthn NSW Jan09

This rather impressive photo from the Adelaide Advertiser shows the impact of flooding in western New England and Southern Queensland now sweeping down the Darling River. The photo is one of a gallery of fifteen.

The floods are big news in South Australia with a concerted campaign to try to force release of water. In just the one issue of the paper there are multiple campaigning stories: see here, here as examples.

I have a rather different view.

We speak of the Murray Darling basin as though it is a single entity. The common phrase Murray-Darling River system is an example. It is not, for there are in fact two quite distinct systems.

The first is the far larger Murray River system, the second the smaller Darling River system. The difference in scale between the two is shown by the map, the Murray at the bottom, the DaMurray-Darling_basinrling on the left running to the top.

Discussion on the "Murray-Darling system" is driven by the Murray. South Australia's water problems are linked to the continuing drought along the Murray.

The difficulty that arises is that when the Murray is dry, the water in the smaller Darling has to be shared not just by those in the Darling River catchment area, but also those drawing from the Murray below the junction with the Darling.  

This creates a basic asymmetry. If the Darling is dry, those in the Darling basin receive no benefits from any flows on the Murray. If the Murray is dry, those in the Darling can lose water to support those on the Southern Murray.

I recognise that I am simplifying. Still, the practical effect is that those along the Darling can lose out. We have seen this already.

If, as argued, the continent becomes drier, the relatively higher water resources in Northern NSW will be increasingly demanded by those in the drier south. The votes are in the south.

Northern NSW does not have its own political entity. There is nothing to offset the political pressures that will come from the south. The North must lose.               


Anonymous said...

I'm South Australian. What if Queensland decided to restrict water flow to New South Wales as New South Wales has to South Australia. I wonder if the Queenslander's are thinking the same as you. A bit more thought required I think Mr Belshaw

Jim Belshaw said...

Hi anon. Queensland is already restricting water flows, cf Cubby Station, to the sometimes not always rationsl distress of those downstream.

I don't think that this actually affects my argument, although I would agree that more thought is always required!

Ben said...

Has the urgency in this been forgotten? Just because we've had rain?

Jim Belshaw said...

I don't think so, Ben. Its been going on in the background.