In South Australia we are lucky to have great beaches and recreational lakes in which to swim and participate in water sports. Along the metropolitan coastline, our beautiful long, white beaches are generally clean and safe for everyone to enjoy. Water quality monitoring completed by the EPA indicated that “beaches were safe for recreational users in terms of microbiology; however, there are instances where the turbidity at some beaches may reduce visibility in the water” (EPA, 2004).
Across the metropolitan area we have a network of stormwater drains that collect run-off from our streets and gutters when it rains. Nearly all of metropolitan stormwater flows to the sea through the stormwater system, as well as the creeks and rivers situated along the Adelaide Plains. These include the River Torrens, Barcoo Outlet, Onkaparinga River and Christies Creek.
The Natural Resources Management Board, together with local councils, has taken action to improve the quality of stormwater. However during large rainfall events water quality does decline for a short period of time.
The water flowing out of these stormwater systems after rain can be discoloured and has contaminants associated with the pollution washed off of our streets. Summer storm events that occur after long dry periods have the largest impact because material accumulated over several weeks is washed into the sea.
Stormwater can be unpleasant to look at, reduces visibility and can smell. There is also a risk that ingestion of the stormwater could cause mild illness such as a stomach upset. It makes sense to avoid swimming in this water which is usually contained to areas near discharge locations. Even after heavy storms, the discoloured water will normally disappear within 2-3 days.
Signs have been erected on some metropolitan beaches to mark sections of beach that have a significant stormwater outlet nearby. They warn beachgoers that polluted stormwater could be discharged into the sea after rain and to avoid swimming if water is discoloured.
Resources Management Board has a network of monitoring stations to assess the
flow and quality of stormwater within creeks and rivers that discharge to the
Stormwater flow is collected on a continuous basis and can indicate when
stormwater events are occurring which could discharge to the sea.
Current data from these coastal sites is presented graphically with a CAUTION icon present when stormwater events are occurring.
Additional information regarding these monitoring stations is available at
the AMLRNRM monitoring network website
or click on a warning sign
on the map to access site information directly.
It should be noted that these datasets are unverified and only provide an
indication of stormwater run-off.