The Southern Spring Flow has reached the central Murray, inundating areas of iconic river red gum forest and replenishing groundwater reserves.
Senior Environmental Water Manager Paul Childs said the flows would achieve a number of outcomes as they moved through the river system and across the floodplains.
‘Water releases essential nutrients into the aquatic food web, which provides a boost to available food for insects, crustaceans, shrimp, fish, turtles, frogs, birds, small and large mammals and plants,’ Mr Childs said.
‘Regular floodplain flows provide a steady supply of carbon and nutrients. Without this injection of food from the floodplains, the only source of nutrients would be the river channel itself.
‘River red gums require regular inundation to grow, flower and set seed.
‘Some of the river red gums in the central Murray are hundreds of years old.
‘When river red gums go without water for more than four years, they are known to drop around seventy percent of their canopy (leaves).
‘When water eventually arrives, the volume of leaf litter increases the risk of hypoxic blackwater which results in low oxygen levels in the water and can lead to increased risk of fish deaths.
‘By providing regular inundation, these river red gums remain healthy, stress-free and contribute regularly to the aquatic food web while avoiding excessive build-up of leaf litter,’ he said.
The river red gum forests of the Murray Valley National Park are Ramsar listed and are of international significance.
The forests have cultural and spiritual importance to the Bangerang and Yorta Yorta people. These forests have evolved over countless generations to survive and thrive through cycles of wetting and drying.
‘Before river regulation, these low lying areas of river red gum forest received flooding flows in most years, even in drought.’ Mr Childs said.
‘Water for the environment allows river managers to mimic some of these natural flow patterns and maintain the health of the plants and animals that live alongside our communities.’
To see the latest update on progress of the Southern Spring Flow, go to the Southern Spring Flow 2019.