Wetlands Australia National Wetlands Update February 2013
Issue No. 22, February 2013
New structures open natural flow paths to long stranded wetlands
NSW Office of Environment and Heritage
New regulator at Paika Lake.
(James Maguire, OEH)
In the spring of 2012, newly installed regulators, pipes and culverts enabled the delivery of environmental water flows to long-stranded Lower Murrumbidgee wetlands located on private property in south western New South Wales.
"The Lower Murrumbidgee wetlands support diverse native vegetation and provide important habitat for waterbirds, frogs and other wildlife. However, Cherax Swamp, Hobblers Lake and Penarie Creek, north of Balranald, were in poor condition after decades without substantial water flows," said Justen Simpson, Environmental Water Delivery Manager for the New South Wales Office of Environment and Heritage (OEH).
To help improve the health of the wetlands system, landholders fenced off the areas from stock and planted wetland plants native to the local area including common reed, lignum and tall spike rush. New structures were installed to enable the delivery of environmental water to the wetlands.
The water infrastructure works, funded by the OEH and Australian Government Biodiversity Fund, include the installation of three water control structures in Yarrawol and Paika Creeks, enlargement of box culverts in the bed of Paika Creek at the Ivanhoe Road crossing and installation of a number of control pipes.
Importantly, carp screens were also fitted at key locations to prevent the movement of adult carp into the wetland areas, to the benefit of native fish populations.
Mr Simpson said Cherax Swamp, Hobblers Lake and Penarie Creek are located north west of Paika Lake where thousands of waterbirds (including threatened species) foraged and bred after the lake was filled last year for the first time in 100 years.
Great crested grebes have been observed
at Cherax Swamp.
As the environmental water flows began to reach the far end of the wetland system and Cherax Swamp filled in October 2012, large numbers of waterbirds were observed. Even early in the water delivery approximately 20 000 black-tailed native hens and thousands of ducks and coots were observed as well as glossy ibis and great crested grebes.
The OEH worked in partnership with the Commonwealth Environmental Water Office and with local landholders to plan the environmental water delivery to the wetlands.
Peter Morton, owner of the property Dundomallee, said the water flows during spring will greatly benefit the growth of newly planted vegetation. "Carp feed on aquatic vegetation and negatively impact on habitat for native fish populations. We have successfully trialled carp screens on a smaller scale and seen the results with abundant aquatic plant growth. These new carp screens along with the environmental water delivery should have a big positive impact on the wetland systems."
A total of 8000 megalitres of environmental water was made available for the event, from Commonwealth and NSW environmental water accounts. The environmental water flow was identified as an action in the Annual Environmental Watering Plan for the Murrumbidgee Valley, developed in consultation with the Murrumbidgee Environmental Water Advisory Group.
For further information on environmental watering in the Murrumbidgee Valley visit the Office of Environment and Heritage website at Murrumbidgee Valley environmental water .
Carp screen at Cherax Swamp.
(James Maguire, OEH)