West Lakes are an artificial marine environment, built to enhance
the local residential amenity in an area that was previously a
natural marsh wetland. Water movement through West Lakes is controlled
by a marine inflow near Tennyson and an outflow to the Port Waterways
at Bower Road. Stormwater drains also flow into West lakes at
several points. The major water quality issues, that are influenced
by polluted coastal waters and stormwater inputs include nutrients,
algal blooms (as indicated by chlorophyll a), faecal bacteria
and turbidity.
>> Map (212KB
PDF)
>> More on the impacts
of urbanisation on streams and coastal waters
Water quality at West Lakes is monitored by Transport
SA and is assessed as being in good,
moderate or poor
condition by interpreting water chemistry and algal (chlorophyll)
data.
>> More
Water quality classification for April to September 2006
|
Indicator
|
Classification
|
| Ammonia |
Good
|
|
|
Good
|
|
|
Good
|
|
|
Poor
|
|
|
Good
|
|
|
Good
|
|
|
Poor
|
|
|
Good
|
Notes NA = not applicable
The water quality monitoring results for this period were generally
consistent with previous seasonal results for this site.
Chlorophyll (a) is often classified as poor throughout West Lakes.
This is probably due to high nutrient concentrations that enter
West Lakes via the intake near Tennyson as well as stormwater
runoff. The high chlorophyll (a) indicates that algae are abundant
in West Lakes, which can cause the water to appear unpleasant
and possibly toxic.
West Lakes water quality was good in terms of the bacterial levels,
although the Department
of Health recommends that people do not swim in West Lakes
for up to three days after rain and avoid areas of discoloured
water. As a general note, the South Australian Department
of Health has useful information on the safe
use of recreational waters.
>> Archived results
The water quality issues in West Lakes are influenced by polluted
stormwater. The Greater
Adelaide and Mt Lofty Ranges NRM Board have a program of educating
industry and the community about reducing stormwater pollution.
The NRM Board is also actively constructing wetlands and other
stormwater management systems within the catchment.
The EPA established the Adelaide Coastal
Waters Study in 2001 in response to concerns about the decline
in coastal water quality. This study is expected to be completed
at the end of 2006 and is designed to answer the main questions
we have about coastal waters. This knowledge should lead to improvements
in the West Lakes inflow water quality.
