I have mentioned before that even if every bit of an average urban garden was planted with food, it would still not produce enough food to sustain a family. Things like staples, the carbohydrates we eat in larger quantities as the bulk of most peoples’ diet, are required in volumes unreasonable to produce on a “quarter acre block”. And so it means we rely on the rural farming communities to provide us with bread and pasta and rice.
When looking at agriculture in Australia, we are really talking about the Murray Darling Basin. This catchment stretches all the way down the east coast of Australia, from southern Queensland, through New South Wales and Victoria and into South Australia. It contains the majority of Australia’s farming activity, and produces a massive proportion of all crops, cereals, vegetables and fruit, including about 40% of the total dryland crops in the country. Dryland crops are those which are grown using only natural rainfall as irrigation. This distinguishes them from irrigated crops, grown using diverted or stored water from surface run-off or waterways. Many cereal crops, such as Wheat (Triticum spp.), Oats (Avena sativa) and Barley (Hordeum vulgare), are dryland crops. Rice (Oryza sativa) is irrigated using water predominantly from the Murumbidgee river, and is a prime example of what sorts of issues arise from this kind of farming.
Rice farming started in the 1920′s in Australia, but massively expanded in the latter part of the 20th century partly due to increased domestic demand, but more so the potential exports to growing economies in South East Asia. Almost all the rice grown in Australia is produced in the Murray Darling Basin, so close to 100% it’s barely worth considering the competition. All of this Rice is grown using flood irrigation during the hot growing season (October to March in the Riverina) with water diverted from the inland river system. While farmers have been reducing their water use over the past few years, and increasing yields, they sill use more water than any other cereal producers in Australia. The main purpose of the flooding is to reduce weed competition, and varieties have been selected over the years to produce best under these conditions. The flooding itself causing low oxygen conditions in irrigated soils, resulting in anaerobic decomposition of organic matter in the soil, and a resulting increase in methane production by soil microbes.
Water used through the growing season seeps into the water table, which is known as deep drainage. While this may not appear to be a big deal, we are talking about 1643 gigalitres (GL) of water, the equivalent of one and a half times the capacity of the Thompson dam (Victoria’s largest water storage). Considering the Thompson is less than half full at present, and rice growers use this much water every year, it may start to ring alarm bells. Deep drainage causes artesian water tables to rise, that is, the increased volume of water underground begins to approach the surface. Due to dissolved salts in the artesian water, (which can be tasted in bore water), the soil salinity in areas with rising water tables may become too high for plant roots to tolerate. Eventually soil salinity can approach levels too high for any plant growth, and once useful farming land is lost. This salinity is similar to dryland salinity, which occurs in non irrigated areas, but is caused by clearing of deep rooted, high water use vegetation resulting in more drainage of rainfall into the water table. Salinity in all its forms is a major threat to agriculture in Australia, both in the Murray Darling and elsewhere.
But we need food! That is reasonable conclusion, against which it is difficult to argue. But it should be noted that only 5-10% of rice produced in Australia is consumed here. The vast majority is for export, in other words, it is on behalf of local hungry pockets that the irrigators really lobby, not local stomachs. Okay, so 40 million people eat Australian rice every day. This is good, we are actually helping alleviate world hunger. But economic forces are at work here, not altruistic ones. People don’t starve for the most part because of a lack of food sources, but because of a lack of access to those sources, which in the modern world means a lack of money. Nobody is giving this stuff away, and at present the rice harvest in Australia is worth over $200 million annually. Sure this is nothing compared to the beef export market at over $3 billion, but let’s not get ahead of ourselves, a lot of that is grown on land that is literally unsuitable for any other kind of farming. Sure, maybe we should just let it go, but it’s a different set of arguments to be had. We are, as it has been pointed out, very good at growing rice in Australia, our yields are about double what the average is in the rest of the world. But if we are genuinely concerned for the rest of the people reliant on rice as a food source, we should be exporting our knowledge to them, not just selling them our rice.
Currently, the situation in the Murray Darling basin is precarious. Irrigated crops draw water from the river systems, and either release it back, polluted with fertiliser, pesticides, or just plain salt, or it soaks down into the water table to cause problems elsewhere. All that flows off the irrigated land, and non-irrigated properties for that matter, ends up back in the river system. This in turn flows into wetlands and estuarine systems and into the sea, where it affects all of the associated ecosystems along the way, by polluting and generally decreasing the quality and quantity of water available for the natural environment. This is greatly discounting the amount of water that doesn’t flow off, due to actually being used by the crops and livestock, and exported from the region and from the country as produce. The nature of salinity means it takes a long time for symptoms to appear, and possibly even longer to reverse them, which is yet another layer of difficulty for the region on which we are so reliant. The federal government set up the Murray Darling Basin Authority to investigate these issues, and soon they are to deliver a plan which was to balance environmental and economic concerns. The Basin supports more of Australia’s agricultural economy than anywhere else in the country, but the rivers that flow through it are vital for the survival of some of our most important natural environments.
It seems as though the Authority has been swung in favour of the economic outcomes, though. After promising to buy back “water rights” from farmers to allow more water to continue down the rivers without being diverted, a recent announcement has reduced the original flow volumes by up to 30%. The Wentworth Group of Concerned Scientists have resigned from advising the Authority, as they have not been allowed access to the “great new science” that has prompted this back pedalling. If ever there was a situation that needed qualified, objective study, it is a situation like this one, where personal gain and conflicts of interest are inherent in the problems. Political group GetUp! have been organising a petition to encourage the Authority to release their “new science” for public scrutiny.
To be honest, I don’t believe there is such a possibility as “environmental flow” when it comes to a scale like this. No matter how much water flows down a river, the organisms that depend on it will be selected by natural processes to survive those conditions. If it’s a lot of water, species will be selected for wet conditions, if it’s less, species will be selected for dry conditions, and if it’s somewhere in between, then the median will select. There is no way humans can predict an “ideal amount” of water to provide, except to maintain an ecosystem in the state they have observed it. This is not natural. It is conservative, but it is not conservation. It is management, pure and simple. There is no way human beings can avoid having an impact on the development of the natural world, especially as it exists downstream from us. The idea of “minimum flows” is a ridiculous misunderstanding of what “natural” means in the first place, as the only truly natural solution would be to remove all reliance on diverted water. That probably includes all the farm dams as well, and water tanks, and drinking water reservoirs, and fish ponds and swimming pools for that matter.
But this is unlikely to happen. One thing is for certain is that there can be no “maximum” flow through the river systems, and the minimum needs to be as high as possible to enable anything approaching a natural amount of water reaching the wetlands and the estuaries. This means any reduction of a minimum flow must be greeted with skepticism, especially where the group who is in favour of such a reduction has so much to gain from it economically, and potentially so much political influence over the government charged with making the decisions.