Picnickers and passers-by often leave their litter behind or, worse, throw it inside the bird sanctuary.
Much litter also washes into the Sanctuary from surrounding roads via stormwater drains.

Environmental Challenges

Litter in Aloe St stormwater inlet

Sewerage Spills

Two pumping stations pump the sewerage which drains from the entire suburb, to the treatment plant a few kilometres away.
Spills into the pan occur due to pump failures, pipe blockages and cracked pipes.

Sewerage inflow aftermath

Feral and




Cats enter the Sanctuary to catch birds and frogs.
Escaped exotic water fowl sometimes appear such as domestic geese, or black swans which have naturalised in the Sanctuary.

Alien and Invasive Plants

Invasive vegetation is our biggest environmental threat.
Some troublesome Category 1b plants found in Korsman include:
   -  Black Locust             -  Spear Thistle
   -  Bugweed                  -  Pom Pom Weed        - Purple Top                Jerusalem Cherry         
Control methods used at Korsman

Galleries of categorised invasives and weeds

Spear Thistle

Water Level Control

As the pan has no natural outlet, it can overflow in times of high rainfall. This reduces biodiversity by flooding the grassland, eliminating habitat for waders and encouraging overgrowth of reeds.
Runoff is higher in recent years due to the higher housing density and large paved areas in complexes.
An evacuation pump in the Westdene North pump station transports the water via the Benoni Lake golf course into Middle Lake.
Cat with frog

Secondary Poisoning

Owls which eat poisoned rats and vermin are killed in turn by the ingested poison. The best way to prevent vermin is keeping the property clean. All rat poisons are dangerous, with Racumin the least toxic.
Dead owl

Invasive Fauna

Common myna birds eat the eggs of and kill chicks of local birds, especially hole nesters such as barbets.

Photo by Eugene Liebenberg
Mallard ducks are a Category 1b invader as they interbreed with Yellow-billed ducks and teals.

Hybrid Mallard photo by Werner van Goethem
Carp are a Category 2 invader which compete for food sources with indigenous fish and dabbling waterfowl.

Photo by Eugene Liebenberg
Asian Harlequin beetles are a variable species that look like ladybirds. They outcompete indigenous ladybirds, carry parasites and even eat their larvae.

Harlequins are recognised by the black W / white M shape on the pronotum (behind the head.)

Air and Noise Pollution

Air pollution comes from nearby industries and illegal rubbish burning.
Noise pollution is caused by industries, firework displays and loud events.


Speeding Vehicles

Vehicles on The Drive kill birds, frogs and crabs, and threaten pedestrians and cyclists.

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