The Lake and its Water

The Lake and its Water

In the early days before the lake was formed, we can assume that a little creek gurgled its way down the valley from Mitcham to Blackburn on its way to the Yarra River. It would have been joined along the way, particularly in winter, by many little rivulets and streams; some of these gullies can still be seen as you walk around the lake today. In summer, the creek may even have dried up at times.

The creek was dammed in the 1880’s and the valley flooded to form the lake, which has a steep embankment on the western side and more swampy edges along the eastern side. It was initially about 50 feet deep where the creek had been mined for antimony, but recent studies show that it is not that deep today, having silted up over the intervening years.

In the 1920’s, diving towers were erected and swimming lessons were held at the lake, the water must have been much cleaner than it is now! The Blackburn Swimming Club was forced to close in 1931 due to vandalism of the facilities.

During the 50’s and 60’s, the lake became a dumping ground for rubbish, and there are supposed to be old car bodies and other rubbish at the bottom. These would have leached acids, lead and hydrocarbons into the water over the years.

In 1962 the dam wall in Lake Rd was built by the MMBW to form a retarding basin to prevent flooding further down Gardiners Creek, and the picturesque Lake Rd Bridge (as shown below and on our postcards available from the reception area in the Visitor Centre) was demolished in 1965.

Before this, residents recall having to change shoes on the north side of the Lake Rd Bridge and don gumboots to cross "boggy hollow" as it was locally known!

Lake Road Bridge, Blackburn

(reproduced from ‘
Blackburn-A Picturesque History’ by Robin da Costa,Pioneer Design Studio Pty Ltd, Lilydale)

Built c. 1888 of
handmade Blackburn bricks.

Demolished 1965

Over the years all the water which flows into the lake comes from stormwater drains. The catchment area has become more industrial, orchards have given way to housing estates and there have been some instances where dyes, sewerage, oils and other pollutants have been either deliberately, or accidentally, released into the drainage system and ended up in the lake. (A map of the catchment is below).

With the vigilant and swift action of observant "friends" and the Environment Protection Authority these spills have been cleaned up quickly and in some cases stopped before entering the lake.

EPA Study - 1995

In 1995 the Environment Protection Authority conducted a study of the water in the lake.

The results showed that

Dissolved oxygen levels are very low below about one metre
The lake is very turbid, although this would reduce the risk of algal blooms considerably
Nutrient concentrations are very high
Sediments contain substantial quantities of heavy metals and extremely large quantities of petroleum hydrocarbons.
Fish and yabbies have accumulated high concentrations of heavy metals and hydrocarbons in their flesh.
Invertebrates found were species tolerant of only very poor water quality.

The lake water is improving!

In the late 90’s, the lake water was considered to be almost dead!

There was no appreciable aquatic life, tadpoles and frogs were rare, carp abounded and even rainfall brought, not fresh water, but oil and petrol soaked run-off from the roads and litter down the drains.

With the lake silting up and eroded banks caving into the water, the verges of the lake are losing the reeds and rushes, home and protection for reed warblers, ducks and other aquatic birds.

However, as bleak as this picture may seem, there is a good population of native ducks, coots, cormorants, herons, an occasional swan or pelican, and a colony of tortoises.

With the dawning of the new century and a lot of hard work and special projects the quality of the water is now improving.

Whitehorse Council has invested funding to remove carp, inappropriate weeds, restore the lake verges, and create suitable access points.

Whitehorse Council and Melbourne Water have made considerable improvements to the inlet from Central Road which can be seen from the Friends Bridge. Construction of wetlands along the major inlet at the head of the lake is about to begin. This work is designed to filter many of the pollutants from the water before it reaches the lake and subsequently the Bay. Litter traps will also be installed to trap gross litter in the catchment area before it enters the lake.

Whitehorse Council, Melbourne Water and the EPA act very quickly to reports of pollution in the lake. The water quality is regularly monitored by Whitehorse Council, Melbourne Water and independent studies such as Boonerwrung Waterwatch.

The Community has a role:

Everyone can assist to improve the quality of water in the lake:

reduce litter in the street
clean up after dogs to reduce the level of nutrients and bacteria in the water
limit the amout of bread given to the ducks; it really feeds the carp and rats
reduce the use of pesticides & herbicides in your garden
report littering or pollution to the EPA or Council
find out if you live, work or shop in the Blackburn Lake catchment area

Duck Stencil The Blackburn Lake Sanctuary Advisory Committee is being assisted by Scouts and local primary school students to stencil drains in the catchment area of the Lake to raisecommunity awareness exactly where the storm water drainage goes. The catchment area starts as far away as the corner of Whitehorse and Mitcham Roads. Litter such as a cigarette butt dropped in the street ends up in Port Phillip Bay!

Look out for the the little duck stencilled on the drain in your street if you live in the catchment area.

From Blackburn Lake to the Bay