“A good wetland should be able to drain and should dry out over the winter after the nesting season once the last of the colonial water birds has completed its nesting season.
The egrets are usually the last ones to nest and fledge their young and so the environmental water should be kept in until the last of the egrets have completed their nesting cycle. But there also needs to be some wetlands with water over the winter as drought refuges for those birds that don’t migrate. A lot of the wetlands dried out during the drought, even so-called drought refuges such as Hut Lake in the Barmah-Millewa forest which always contains water.
Bush bird numbers crashed during the drought and they have yet to fully recover. You would think it was impossible to come in to the forest and not hear or see pardalotes or honeyeaters but their numbers did fall off considerably. A farmer asked the president of our bird club ‘Where have all the bush birds gone?’ and he replied ‘They’re dead.’
A lot of people seem to be opposed to environmental water being released in to wetlands along the Murray River thinking that the water is wasted, gone, but that’s not true. In the case of Barmah-Millewa, one of the CMA and DSE representatives tried to measure the amount of environmental water going in to the Barmah-Millewa forest and over a period of time measured the water coming out and they concluded the B-W is like a bucket of water with lots of holes in it. The environment body that did studies on the NSW side found that at least 80 percent of environmental water was flowing back in to the system which can be used downstream by irrigators and in towns.
I’m concerned about people who doubt the word of the science and people have the gall to think they know better than experts in the field. And when scientists who are experts in ecology and hydrology tell us the wetlands are in trouble and need more water we should be listening. In this case we have the Wentworth group of scientists telling us we need more environmental water and we should be listening to their arguments.
There’d be several adverse consequences if there was any reduction or no increase in environmental water allocation.
One is the giant rush, Juncus ingens , which is native could take over some of the remaining moira grass plains. We’ve lost most of the moira grass plains, and they provided excellent habitat for brolgas and other birds, which are nowhere near as numerous these days. What happens is that in the past, floods would have been deep enough to drown young saplings and kill them off, and it would have been deep enough to perhaps limit the expansion of Juncus ingens, the world’s tallest rush. So we would lose our remaining moira grass plains such as Steamer Plain, unless action is taken.”
By Ian Kenins, Environment Victoria, February 2012