Snowy River flow release

After years of drought in eastern Australia, a large environmental water allocation is good news for a river.  It’s particularly good when it’s for the Snowy River.

The Snowy River, iconic in Australia (think the 1980s acclaimed ‘Man from Snowy River’ movies), is a large snow-melt river, something that is not too common in Australia.  It links the Snowy Mountains, in New South Wales, to the Bass Strait, between Victoria and Tasmania, and in former natural conditions it had a huge flow during spring and summer.

Dammed in the 1950s as part of the Snowy Mountains Scheme supplying hydroelectricity and irrigation water for south-eastern Australia, the Snowy River’s ecology and geomorphology have endured 50-60 years of extremely low flows. The new Jindabyne Dam captured about 99% of Snowy River flows downstream.

In 2000 , the Snowy River was the first major, high profile environmental flow allocation decision made in Australia.  The joint Commonwealth-NSW-Victorian Government decision provided $375 million to recover 282 GL for the environment (210 GL for the Snowy River, 70 GL for the River Murray).  This was based on a target to restore 21% annual flow to the Snowy River below Jindabyne Dam by 2010 (and up to 28% post-2010).

Since that time, a consequence largely of nearly a decade of drought, not much environmental water has made its way down the Snowy (less than 50 GL in total or about 4% natural annual flow).

But, it’s just been announced that 84 GL will be released into the river during October over a 3 week period, and that flows should reach 12 GL per day for 3 days during that period.

The release is said to be ‘the biggest environmental water release into the Snowy River since the construction of the hydro-electric scheme’.

Last November, environmental flow releases of 3 GL per day into the Snowy over 4 days were the largest since the 1950s.  Monitoring and assessment afterwards found effects on the salinity of the estuary, and some scouring of the upland channel, although confused by ‘freshes’ from rainfall. More of the river bed was inundated, but there was not enough flow to cover relatively small natural barriers in the river which limit fish passage.

This newly announced release follows years of water recovery by the ‘Water For Rivers’ joint government enterprise set up after the 1998 Snowy River Inquiry.

It is good news for the Snowy!

*1 GL = 1 billion litres = 1 million cubic metres = 811 acre feet

Snowy River downstream of Jindabyne Dam ...waiting for the flow! (NSW Office of Water photo)

 

One thought on “Snowy River flow release

  1. A lot of emotion is caused by the statement that only 1% of water flows down the Snowy River. In fact the Jindabyne dam only captures 14% of the Catchment Area. Hence 86 % ( less the Mowamba River) of the Catchment Area is unregulated. The Snowy downstream of the Delegate River has good flows. The Snowy River at Orbost has flooded many times including the 1971 record flood since the Jindabye Dam was commissioned in 1968.

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