Rice growers along the Murrumbidgee River are likely to be among the hardest hit if the federal government proceeds with its new water sharing plan. If the region loses 45 per cent of its current allocation as proposed by the Murray Darling Basin Authority, an unintended consequence will be a dramatic decline in the populations of over a dozen species of frog. These frogs have benefited from water being pooled in upper catchment areas for rice production; if the plan goes ahead more water will end up going down to South Australia and over the barrages into the Southern Ocean, to the detriment of flood plain wildlife.
Early explorers, John Oxley and later Charles Sturt, described what is now known as the Murrumbidgee Irrigation Area as a desolate, uninhabitable landscape. That was before irrigation. Today the region produces wine grapes, citrus, apples and stone fruits, vegetables, wheat, barley, oilseeds and, of course, rice.
Proud locals boast that despite the drought, and because of irrigation and the vertical integration of the food industry, 160 semitrailer loads of quality, fresh food ready for the supermarkets of Australia leave the towns of Leeton and Griffith each day, and a further two and a half trains of containerised food for markets around the world. Not all is produced on irrigation farms, but the certainty irrigation provides has facilitated the development of the food industry with value adding occurring locally to an industry now worth between$2.5 and $3 billion annually.
Leeton is known as the headquarters for the Australian rice industry, and is the location of one of Australia's most successful, vertically integrated agribusinesses - SunRice.
In years of adequate water about 150,000 hectares of rice are planted across the Murray Darling Basin providing habitat for an estimated 5 billion frogs. The spotted grass frog, barking marsh frog, plains froglet and Peron’s tree frog are four of the most common species which live in remnant patches of bushland and breed in flooded rice bays and irrigation channels between August and May. Scientists at the Institute of Applied Ecology at the University of Canberra estimate that every hectare of Australian-grown rice produces 33,000 frogs in addition to the almost ten tonnes of rice.
Of course birds eat frogs, and so perhaps not surprisingly the Murrumbidgee Irrigation Area has also become home to thousands of water birds including rare migratory species.
Incredibly the Guide to the Proposed Basin Plan released last Friday does not mention the word “frog”, or “Amphibian” - not once.
The Guide recognises that most of the 30,000 wetlands scattered across the Murray Darling Basin are on private land and states there are 2,442 key environmental assets across this predominately agricultural region.
In fact during the last 90 years through a constant improvement in management, irrigation techniques, fertility and productive capacity the “desolate” plains are now teeming with wildlife. Of course not all frog species have thrived all the time with the endangered Southern Bell frog undergoing recent decline from the introduction of exotic fish and the degradation of some wetlands particularly from overgrazing.
It was progressive politicians who witnessed the devastation and totally dry rivers that accompanied the droughts of the 1860’s and the late 1890’s that drove the early development of irrigation in the Basin: they wanted to conserve water at times of excess, to sustain farming communities even in drought years. Few realise that since European settlement the Murrumbidgee has run bone dry four times: during the droughts of the 1840s, 1860s, 1890s and 1913-1915. It was so dry in the early 1860s that horse races were held in the bed of the Murrumbidgee River downstream of Gundagai.
Water infrastructure is now extensive across the Basin, so, even during the recent prolonged drought, there was enough water in the Hume and Dartmouth dams to provide for the world’s largest ever environmental water release in October 2005 with 513 gigalitres of water (the equivalent of a Sydney Harbour of water) released into the Barmah-Millewa red gum forest which straddles the Murray River upstream of Echuca.
Without the dams, given the severity of the drought, the Murray River would have likely run dry over the last decade - never mind having enough water to flood a very large forest.
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