Snowy River environmental flows 2011

Snowy River environmental flows 2011


The Snowy River is raging once again thanks
to an agreement by the New South Wales, Victorian and Australian governments. In the 40 years Jill and Bruce Hodges have
lived by the Snowy River, they’ve never seen it quite like this before. Bruce Hodges: “Well a granddaughter came
down yesterday and said ‘Oh you’re not beside the river, you look like you’re beside
the ocean,’ when she could see it from the house. It’s quite a different view. We can normally hear the river at home, but
at night time now …” Jill Hodges: “It’s quite loud.” Bruce Hodges: “Even me with my bad hearing
can hear what’s going on.” The river started roaring past the Hodges’
property after a mass of water was let loose from Jindabyne Dam, just upstream, to increase
environmental flows. Over 19 days in October 2011, 84 billion litres
– about 42,000* Olympic swimming pools worth – were released from the dam in an exercise
carefully managed by Snowy Hydro Limited and the New South Wales Office of Water. The river’s headwaters run from Mount Kosciuszko,
Australia’s highest peak, and historically its naturally fast flows are a result of rain
and melting snow gathering speed in the mountainous catchment. But with regulation of the Snowy River in
the sixties, these fast snow-fed flows have all but disappeared. Without strong flows to flush the system,
silt and rocks have built up, smothering habitat for native species. In 2010, top-layer silts were effectively
dislodged from the river bed by a smaller release of nearly 17 billion litres of environmental
water, the first of its kind in the Snowy River. This 84-billion-litre release is five times
bigger and strong enough to flush out rocks the size of footballs, allowing silt trapped
underneath to also be washed away. Simon Williams, New South Wales Office of
Water: “All the rocks on the top are heavily armoured, they’re all locked together, and
below those rocks is a series of heavy silts and muds. We want to move the rocks and scour the silt
and mud out of the bottom of the river.” The clean river bed will provide habitat for
the invertebrates that native animals, including platypus, feed on. Scientific monitoring will track the long-term
success but already there are promising signs. Simon Williams, New South Wales Office of
Water: “A lot of the plants that are growing into the river channel, we actually saw them
when the water was first released actually being picked up and moved down the river,
which is what we want; we want to be able to create a more defined river channel, we
want that vegetation out of the channel.” The releases are timed in spring to mimic
the high flows the river experiences under natural conditions as snow melts off the Snowy
Mountains and runs into the river channel. Spring releases of this year’s scale are
set to become an annual event for the Snowy River, except in dry years, thanks to investment
by the New South Wales, Victorian and Australian governments. * based on 1 GL or 1 billion litres=500
Olympic swimming pools

Leave a Reply

Your email address will not be published. Required fields are marked *