|
|
Sand
mining
Stormwater
runoff
Illegal
rubbish dump
Pepper
tree
Cats
Claw
|
|
Extraction
The majority of current and past operations have
been worked without any planned rehabilitation. The 'closing of the
gate after the horse has bolted' has devastated the creek environmentally
and may take millions of dollars to rectify.
Since European settlement, the sand of both Oxley and Blunder Creeks
has been mined extensively, particularly in the lower and middle reaches.
It has been the biggest source of prime building sand in Brisbane. Typically,
mining recovers sand from dredging pits and, in the washing process,
silt and clay remains suspended in water held in settlement ponds. This
suspended material increases the murkiness or turbidity of the creek
when floods breach the ponds. High turbidity can cause gill damage in
fish, smothering of aquatic plants and bottom dwelling animals, increased
temperature, and reduced visibility. Sand mining has also cleared the
catchment creek banks of natural vegetation, altered the natural creek
flow and increased erosion.
Contamination
Stormwater runoff is one of ways contaminants
enter waterways. Dog faeces, careless disposal of industrial, household
and garden wastes, detergents, effluent from Wastewater Treatment
Plants, removal of wetlands and natural vegetation which once filtered
and slowed down runoff and illegal dumping and the filling in of watercourses,
all contribute to contamination of our waterways.
Infestation
When the natural bush is disturbed or removed,
exotic weeds and species soon establish themselves. Their seed are
spread by birds, animals, wind, humans and water. A number of species
will root naturally from cuttings and unless controlled soon establish
a dominance or in some instances, a monoculture. Birds and wildlife
can survive in some circumstances, but prefer natural or rehabilitated
vegetated areas.
|
Chinese
Elm
|
Camphor
laurel
|
Cats
claw creeper
|
|
Lantana
|
Madeira
vine
|
Morning
glory
|
|
