No more dams

KAI DAHL (TC, 6/9) suggests that Australia need more dams to sustain our growing population. No we don’t. More dams, in a country that already stores more water in dams than any other country on earth will solve nothing, just create more problems.

Regarding the threat to native animals from dams, Australia’s native animals have evolved over millions of years, we’ve evolved here over 231 years. Our river systems are a lot more complex and there’s a lot more going on in and around them concerning wildlife than what meets the eye of a casual observer or politician.

As an ecologist, let me give you just one example. Australia’s freshwater turtles. One species endemic and monotypic to NSW and listed as critically endangered (the Manning River turtle) only inhabits an area approximately 75 square kilometres of a system that covers some 8420 square kilometres and is severely fragmented. Why? Because of the entire system, only 75 square km of it can sustain the reptiles due to their complex, specific evolution.

They require, (due to the way the breathe oxygen via cloacal respiration), shallow clear, continually fast running riffle zones free of sediment adjacent to steep overhanging banks and deep pools with underwater caverns containing sunken timber log jams, benthos vegetation and macrophyte beds containing macro-invertebrates. They require gently sloping sandy banks on the eastern side of the river facing west for nesting.

This is a species that’s 55 million years old and has a generation gap of 20 years.

Already facing environmental pressures from farming practices, deforestation - land clearing, fertiliser and chemical run-off, the resulting degradation, trampling from cattle eroding river banks thus affecting water quality and causing increased turbidity combined with high percentage nest predation from the introduced European red fox.

It won’t just “up and move” if a dam was built on that river system, it would go extinct within two years. That is just one example of one species in one river system. I could write you a document that would be thicker than the Toowoomba phonebook of all the species that would be threatened by more dams.

Another standout is the Mary River system in Qld. It would have been an environmental catastrophe if the Traveston crossing dam had of been built, thankfully the federal environmental minister at the time, Peter Garrett cancelled it in November 2009.

There’s tens of examples for every other system on this continent. It’s not as simple as whacking up a wall to hold back the water thinking it’s the silver bullet solution for everything and everyone, it’s quite simply not.

No more dams. KEV McKAY, Toowoomba