Page 2262 - Week 06 - Friday, 27 June 2008
Molonglo Valley ecological impact review quotes a 1998 report by Adair and Groves which describes the area downstream of Coppins Crossing as “one of the important wildlife corridors linking the river system and mountain ranges to the urban bush and waterways of Canberra”.
It is the habitat for plant and animal species considered threatened under ACT and commonwealth legislation. While it is already known that it provides nesting sites and home territories for the wedge-tailed eagle, the brown gosling and brown falcon, O’Sullivan and Beitzel advise that further work is needed on the impacts of river adaptation on the survival of the pink-tailed worm lizard.
The proposed lake option affects 6.8 kilometres of river length, including a corridor nature reserve. There are many impacts of the construction of a dam which have been left out of ACTPLA’s considerations, including: the construction itself and the development of urban centres nearby, meaning greater sediment and nutrient loads entering the river and contributing to blue-green algae attacks in warm weather. We all know this is becoming a recurrent problem for Canberra’s other lakes. As well, invasion by non-native species will be made easier by the more conducive habitat of relatively still, cold and deep water. It is just what carp love!
Any benefits that ACTPLA and the lake supporters can claim for the lake in terms of water quality may be outweighed by the negative consequences, including increased sedimentation and disturbances caused by the dam’s destruction. The building of Tuggeranong town centre and lake was observed to reduce platypus and macro invertebrate communities. The only way this can be prevented is by ensuring that all water that enters the lake is as clean as is possible. This is an outcome yet to be achieved for stormwater entering any of the other lakes.
Three main options were considered for managing stormwater in the Molonglo Valley: a lake and a Weston Creek pond, a lake and a number of ponds and a chain of cascading ponds. All the environmental studies commissioned to look into these options found that the environmentally preferred option would be the chain of ponds. By the way, nobody looked at the option of leaving the river as a river with rehabilitated wetlands and protected river verges. I think that rivers certainly can have a place in cities.
The Molonglo River corridor boundary study of 2007 recommended against the lake because it would be incompatible with the environmental criteria—ecological, environmental, water quality, flood levels, landscape, cultural and recreational—of the national capital plan. Yet this work has been entirely dismissed, and instead ACTPLA and the NCA are championing a lake. By contrast all the ecologists that I have made contact with strongly oppose this approach. I could go into much more detail here, but I trust that ACTPLA has read the submission I made to them and that the NCA has read the submission I made to them on their proposed plan variations.
I would also like to point out my disappointment on discovering that public transport appears to be an afterthought in this planning regime. I am concerned that the new town in Molonglo will end up with the same public transport deficit as Gungahlin unless planners’ attitudes change. I was shocked to find that, although much of