Photo: Australian
Water Quality Centre |
Introduction
Willochra Creek is in the Flinders Ranges and flows into Lake
Torrens. It is a naturally saline stream with bank vegetation
dominated by samphires. The main land use in the catchment is
broad acre grazing. Elevated turbidity and nutrient levels are
the most likely water quality problems. Stream
flow for this site is available from the Department
of Water, Land and Biodiversity Conservation. >>
Map (739KB PDF)
Water quality assessment
Water quality is assessed as being in good, moderate or poor
condition by interpreting water chemistry data in the context
of protecting environmental values. >>
More
The ecological health is assessed in spring and autumn. We use
macroinvertebrates for this purpose because they provide a relatively
simple way to assess the health of an aquatic ecosystem. >>
More
We measure chemical indicators because when they reach a certain
level they can cause stress or toxicity to animals and plants
in an ecosystem. Water chemistry is measured in Willochra Creek
every three months (rather than monthly) because of its remote
location. >> More
Ecological health
We collect two samples of macroinvertebrates, one from riffle
(or flowing water) habitat and one from edge (still water) habitat.
The diversity of the macroinvertebrate community is used to describe
ecological health as being in good,
moderate or poor
condition.
Go
here to find out how we classify ecological health in streams.
Ecological health assessment for May 2006
| Habitat |
Ecological health
|
| Edge |
Moderate
|
| Riffle |
Habitat not present
|
Willochra Creek is a naturally saline stream. This site is usually
rated moderate as it contains only those animals that are able
to tolerate very high salinity levels. A riffle habitat has not
been present at this site during spring since sampling began in
2003.
The edge habitat only had 11 different types of macroinvertebrates
present in autumn 2006, mostly non-biting midge larvae from the
family Chironomidae (Tanytarsus bartitarsus) and dytiscid
beetles that included Necterosoma penicillatus. Notably
the hydrophilid beetle Laccobius zeitzi, an indicator of
saline waters, was found at the site.
The site rated as slightly impacted due to the absence of numerous
macroinvertebrate groups, such as worms, mites, crustaceans, mayflies,
waterbugs, odonates and caddisflies. The high salinity of the
creek (about 30,000 mg/L) would affect many of these macroinvertebrates.
The salinity would also limit the growth of aquatic plants that
provide habitat for macroinvertebrates to utilise for shelter
and food.
Download ecological health data
Water chemistry
The indicators that are measured in the Willochra Creek are nutrients
(nitrogen and phosphorus), turbidity and salinity.
The concentrations of these indicators are used to classify the
water chemistry as being in good,
moderate or poor
condition, according to the needs of aquatic ecosystem protection.
Go here
to find out how we organise and classify the chemistry data.
Water chemistry classification forApril to September 2006
|
Indicator
|
Classification
|
|
|
Good
|
|
|
Poor
|
|
|
Good
|
|
|
Moderate
|
|
|
Good
|
The water quality monitoring results for this period were generally
consistent with or lower than previous seasonal results for this
site, with high total nutrient concentrations and quite low soluble
nutrient concentrations. There is no shade cover over this creek
and limited aquatic plants due to the naturally high salinity
(from groundwater inflows). The high total nutrient concentrations
are usually attributed to the extensive algal growth in the creek.
Nutrients and can be elevated by animal wastes being washed into
the river during storms or by livestock and native animals directly
accessing the creek.
A catchment study has been completed for the Willochra catchment
(Department
of Water Land and Biodiversity Conservation). The Northern
and Yorke NRM Board are supporting landholders to restrict
stock access to the creek and encouraging revegetation with local
native species.
>> Archived results
Download water chemistry graphs
Download raw chemistry data
What is being done to improve the condition
of South Australian rivers and streams
Efforts to improve the condition of South Australia's rivers
and streams are being driven by various government agencies, primarily:
The Environment Protection Authority
The Department
of Water, Land and Biodiversity Conservation
Natural
Resource Management Boards
Department
for Environment and Heritage (SA)
Collaborative projects and programs being run by these agencies
are based on the protection of environmental values, as explained
in the National
Water Quality Management Strategy. >>
More
This page was last modified 25-09-2007
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