What’s happening to the lake?
As stormwater enters the lake it is slowed by the sudden widening of the water body. Slowing of the flow was designed to allow sediment and nutrients to be deposited as the water traversed the lake’s length. This, however, has meant that the depth of the lake has been reduced over time as the sediment built up.
Plants that normally wouldn’t be able to grow in deep water have almost taken over as the sediment has built up. While in some ways good, because they can absorb excess nutrients, the rampant plant growth is detrimental to some of the native wildlife. The large waterbirds, like swans and pelicans, no longer have enough open water on which to land and take off again. Waders, like black-winged stilts and black-fronted dotterels no longer have the lake edges along which to wade and catch their food.
The current stage of work is to remove the excess plant material. Work started in early March 2013, but we now need an excavator to come in and finish the job. This is expected to happen on April 26. However, there are areas an excavator is going to have trouble accessing. In these areas the Friends have started removing some of the Typha by hand.
Further work will be required to reshape the bottom of the lake to return it to full function. Sedges will be planted around the lake edges to provide less invasive habitat and regular maintenance will be required to ensure the lake continues to function at its best.