Wednesday, February 13, 2013

Environmental Flows and River Health



There have been 2 well known rivers in NSW that have had significant alterations to their health as a result of damming and water diversion for agriculture.  One is the  Snowy river and the other is the Murray-Darling.  We will concentrate on the Snowy River.

As a result of the Snowy hydroelectric scheme, water flows of the Snowy River fell by 95-99%.  Because of this severe degradation, the river had silted up, weeds and feral plants were established, and the fish life was dying out. Scientists had established that it would take 28% of the original flows to restore the river back to good health.




In the late 1990's the NSW and Victorian governments agreed to release this water into the river, gradually increasing it to the 28% level about a decade later.  The drought from 2000-8 caused the governments to hesitate because water was being diverted to agriculture.

Eventually court action by local environment groups force the release of water in 2011.  Water is released seasonally as to mimic the spring snowmelt and copy the behavior of the river in a natural state.  This cylce of large and rapid releases has cleared the river of a lot of the silt and debris, and it is hoped that indigenous water fauna will now return.




A YouTube link is below:

www.youtube.com/watch?v=55WUBhBibkw

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