Case study of sub-region Barmah-Millewa Wetlands Slide 2
Geographic Characteristics Location- the sub-region straddles two
states, Southern NSW and Northern Victoria. Its scale is 66,000ha
of floodplain between the townships of Tocumwal, Deniliquin and
Echuca. Slide 3 Barmah choke The capacity of the River Murray at
Yarrawonga is 25,000 ML/day but at the Barmah Choke it is only
about 8,500 ML/d The Barmah Choke acts like a partial dam, forcing
floodwater to frequently back up onto the floodplain, thereby
inundating the extensive River red gum forests of BarmahMillewa
Forestexplaining the triangular shape of the forest. Slide 4
Wetlands Are regions either temporarily or permanently covered by
water and can be either natural or artificial with water that is
still or flowing, fresh, brackish (slightly salty) or salty. Slide
5 Why are wetlands important? Slide 6 It forms the largest river
red gum forest in Australia and is valued for wood products,
grazing, conservation and recreation. High ecological value and
cultural significance to Indigenous people and the broader
community It is listed on the migratory bird agreements between
Australia, China and Japan- Ramsar list of designated Wetlands of
International Importance. Regularly supports 20,000 or more
waterbirds- supports large breeding colonies of Australian White
and Straw- necked ibis. It provides habitat for the endangered
Superb parrot Slide 7 The Cadell Tilt Block Slide 8 The forest
contains a diverse range of wetland environments and, the Murray
River crayfish and many other threatened plant and animal species,
including native fish and reptiles. It is an important source of
food for fishes, spawning ground, nursery and/or migration path on
which fish stocks, either within the wetland or elsewhere, depend.
It relies on regular flooding from the Murray River for it
survival. YouTube - BARMAH FOREST Slide 9 Problems and changes Over
the last century, the construction of dams, regulation of flow and
the extraction of water to supply irrigators has changed the
frequency, magnitude, timing and duration for the flooding. The
Barmah-Millewa Forest is downstream of Hume Dam and Yarrawonga
Weir, which regulate River Murray flows. As a result, the natural
pattern of river flows and flooding in the forest has altered
significantly. There is now less variability and an overall
reduction in the volume of water. Storage of catchment runoff in
winter and spring has reduced the frequency and extent of natural
floods across the floodplain. However, water released for
irrigation during the summer months has increased unseasonal
flooding of low-lying floodplains. Most of the river is flooded
less often and for a reduced amount of time in the past. Some low
lying areas are flooded more often because of the way the river is
operated for irrigation. Overall health of the forest has declined.
Slide 10 Living Murray Initiative Policy established in 2002 in
response to declining health of the river system Aim to achieve a
healthy, working, Murray River system by ensuring more water is
available for the river. Strategies- $500 million to improve
irrigation systems and water buy backs from willing sellers. 6 icon
sites throughout the MDB. Slide 11 Location of icon sites Slide 12
Living Murray Ecological Objectives The Living Murray objective for
the Barmah- Millewa Forest is to enhance forest, fish and wildlife
values by: successful breeding of thousands of colonial waterbirds
in at least three years in ten healthy vegetation in at least 55%
of the area of the forest (including virtually all of the Giant
rush, Moira grass, River red gum forest, and some River red gum
woodland).
