Floods and Dams

The first week of 2011 sees near-record flooding across sub-tropical north-eastern Australia.  The Fitzroy River, flowing out to the Great Barrier Reef (GBR) Lagoon near Rockhampton, has peaked at flood levels last seen in 1991.  The Condamine-Balonne River, the northern most river valley in the Murray-Darling Basin, will peak over the weekend at levels almost certainly higher than last year’s record flood.  And the Cooper Creek in Queensland’s south-west is flooding into the Lake Eyre Basin, an internally draining system that fills only a few times a century (though, incredibly, it filled last year as well, the first time since 1990).

Thousands of homes and businesses have been damaged and, while there will be long term benefits for farmers from more water in farm storages in and in the soil profile, many farmers have lost stock or this season’s crops.  Coal mines have also been flooded in an area that produces 50% of the world’s steel-making coal.  World coal prices have jumped in recent days in response.

From an environmental perspective, the news is both bad and good.  In the short term, muddy Fitzroy River discharges to the GBR lagoon will cause significant coral die-back.  Algal blooms are also possible, as are outbreaks of the coral-destroying Crown of Thorns Starfish.  For the inland draining rivers, ‘blackwater’ events are possible where tannin rich water, ponded over the dry period in floodplain billabongs, is flushed out into rivers causing mortality to fish and other river animals.  In the longer term, the effects on the environment are nearly all positive.  Fish, bird, amphibian and crustacean populations usually explode after floods, and floodplain vegetation will have a massive growth spurt in response to the increased soil moisture.

On the political front, the climate change sceptics are out in full cry already, along with those who yet again want to try to ‘drought-proof’ Australia.  Conservative politicians are already calling for more dams to capture the ‘wasted’ water flowing south over the border or to the ocean.  Federal opposition leader Tony Abbot has today said that his party will develop a new plan for a “series of dams around the nation”.  Mr Abbott, quoted in today’s newspapers, said “I just think it is a bit odd in a country with as many water issues that we’ve got, that there have been virtually no dams built in the last two decades”.

There will be those in the water industry who agree with Mr Abbott, but there will be many others who will take some convincing that building more dams in rural Australia will solve our agricultural water shortage problems.  It is a bit like thinking that new freeways will solve our urban traffic problems.  Yet we know that bigger roads just bring more cars and bigger traffic jams.  Likewise, more dams always bring calls for more water use and more irrigation.  And dams almost inevitably bring more environmental degradation.

It is also hard to believe that we would have the political will to leave water sitting ‘in reserve’ in these dams, just waiting to help irrigators get through the next drought.  History shows us that we cannot resist the temptation to use up the water in our storages ….saving it for a sunny day is just not in our nature.

And a Happy New Year to all !!……

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