To Paradise and beyond - Page 7
From Griffith REVIEW Edition 20: Cities on the Edge
© Copyright Griffith University & the author.
Written by Peter Meredith
HEADING NORTH ON THE Bruce Highway, downstream from the proposed dam site, I get brief glimpses of the Mary, mostly wide, green and dawdling. On the edge of Tiaro township, the administrative centre of Tiaro Shire (population 4,800), the river flanks Petrie Park, a shady camping and recreation area. The river is about fifty metres wide here and almost still. It has another eighty kilometres to go before it reaches Hervey Bay.
As families mess about in boats in the background, I talk with sixty-two-year-old Darryl Stewart, a pig farmer and shire councillor. He has a businessman's no-nonsense air, an effect softened by a greying beard and moustache. His resonant voice would be useful in the council chamber.
The Mary River is not pristine, and Stewart describes what ails it. The problems, he says, stem from a barrage built in 1982, about twenty-three kilometres downstream at the behest of farmers, mostly sugarcane growers looking for more irrigation water. The barrage acted as a dam, blocked upstream tidal movement that once reached Tiaro and created a permanent reservoir of fresh water that could be pumped to towns and farms.
The barrage has had dire environmental impacts even while it has provided huge benefits, Stewart says. Where previously the river rose and fell twice daily, now it's always still and wide – and getting wider and shallower all the time as the banks slump and erode. The number of fish species in the river upstream from the barrage is nearly 70 per cent lower than on the downstream side, and aquatic weeds such as water hyacinth and salvinia are thriving.
Stewart believes a dam at Traveston Crossing would worsen these impacts. Water extraction at Traveston Crossing would stem the Mary's flow and reduce the number and intensity of the floods that flush the river and keep it healthy. A large loss of flow would have catastrophic impacts on society in the region as well as the natural environment. With less water for homes, industry and farms, the regional economy would slump. ‘A lack of water is going to mean a downturn in cropping production. Maryborough Sugar Factory is estimated to put $40 million a year into the Maryborough economy. Without irrigated cane, that figure is likely to drop by about half and that would seriously affect the viability of the factory. It's one of the major employers in Maryborough, so job losses are going to be pretty huge.'
If farm production fell, farmers would lay off workers. This would hit towns like Tiaro, where small business is vulnerable. Stewart's intensive pig-rearing operation relies exclusively on the Mary for water. ‘If there's no water in the river, our business is no longer,' he says. ‘The Mary is the lifeblood of the community in this catchment. Damming it will have a huge social effect. It's one of the dumbest ideas I've ever heard.'
BEYOND MARYBOROUGH, the Mary River does a ninety degree jink to the south-east, then loops back twice on itself before widening out into Great Sandy Strait about fifteen kilometres south of the city of Hervey Bay. It ends officially at River Heads, a terminal for Fraser Island ferries and a picnic area. Here, to the clank and roar of boats being launched at the ramp nearby, Roger Currie, an environmental scientist contracted to Maryborough City Council and a member of the Wide Bay Conservation Council, explains why worsening conditions in local inshore waters will worsen even further with a new dam on the Mary.
With a dense white beard and bushy ponytail, Currie looks like a character from Lord of the Rings. He is, nevertheless, very much of this world. He has lived and fished recreationally hereabouts for more than thirty years, and thus has a good historical perspective on the area's fisheries.
‘A statistical analysis of the fisheries yield in the region over the past twenty-five years shows a significant decline,' he says. Dams on the Burnett and the barrage on the Mary are partly to blame because they reduce the flushes that bring huge quantities of nutrients into the Bay and stimulate fish breeding. There's every reason to believe Traveston Crossing Dam would worsen the situation. ‘This area relies enormously on recreational fishing. It brings in about $30 million a year. This will be under threat as a result of the dam due to the reduced flows and the impacts on fisheries productivity. There will be an economic loss to commercial fishing too. For instance, scallops are totally dependent on nutrient flow from the river. So the scallop industry is under threat, as is the fledgling pearl industry. Both have been supported by the Federal Government.'
While scientists and fishers are sure that reduced river flow and smaller, less frequent flushes will have detrimental impacts on fisheries in Hervey Bay and the Great Sandy Strait, no one is sure how, or whether, flow changes will affect the salt content of inshore waters. Some believe altered salinity may impact on whale numbers in the area. Whale-watching, recreational fishing, the Ramsar values of the wetlands and the world heritage values of Fraser Island just across the strait all buttress Hervey Bay's tourism industry. The threat of change that many people believe will be for the worse hangs over them.
This preys on the mind of lawyer Steve Dixon, president of the Hervey Bay Chamber of Commerce. Since the 1960s, Hervey Bay's population has grown more than tenfold to fifty-five thousand people. This growth has been driven largely by a search for a particular lifestyle, Dixon says. ‘That lifestyle is interwoven with our environment. Most people who come here, whether as new residents or visitors, have a fishing rod in the boot. The recreational fishing industry is substantially larger than the commercial fishing industry here. This city is built around tourism.'
Dixon recognises that the $1.6 billion due to be spent on the dam would benefit local business, but he doubts that the gains would offset the losses from the dam's impacts. ‘The issue is: what will the damage be when you start reducing flows from River Heads? I think it will be substantial. We really want to see good reasons for building this thing.'
Joe Mcleod, deputy president of the Independent Trawler Association, is a commercial fisherman who reckons he has plenty of good reasons why the dam should not be built. A compact, chunky bloke with amazingly fair skin considering his lifestyle, he has been working out of Tin Can Bay, at the southern end of Great Sandy Strait, since his twenties. He tells me that over this thirty-year period he has seen the increasing restrictions on the flow of the rivers reduce the size and frequency of big flushes. Ask older fishermen, he says, and they'll tell you that a year or so after a big flush there is a bumper crop of fish, prawns and scallops.
Fresh river water also reduces salinity in bays and inlets. Many sea creatures need less salty water during breeding and growth cycles. Around the mouth of the Burnett, McLeod says, only species that tolerate very salty water have survived; others have disappeared. The banana-prawn industry has been particularly hard hit.
Although freshwater run-off from Fraser Island may partly compensate for reduced Mary flow if a dam is built, ‘no one can convince me that the marine population will stay the same,' McLeod says. ‘Some species will dwindle; others will be severely impacted, the way it's happened already with the Mary River barrage. The carrying capacity will definitely be reduced.'