Many people are now discussing water security as the issue hots up. It will be the hottest of issues as demands for fresh water increase with rising population and increased usage. Because it is not just water piped into homes that is the issue here. In fact water piped into homes only accounts for a small proportion of the fresh water we use. Much of it is used in agriculture and industry. Much of the fresh water from around the world comes as run off from mountains and hills feeding into rivers and lakes. The rivers are then used to irrigate crops, taking the water from the river before it reaches the sea. For this reason many of the worlds largest rivers are not actually reaching the sea much anymore. The Yellow River in China is one example.
So how does an increasing population adequately supply itself with enough water to supply its industry, its homes and its agriculture? For example Coke, the most popular soft drink in history, with an addictive quality, takes nine parts of water to create one part of Coke. In some areas of California for example, there is a stretch of prime arable land which has been artificially created by engineers and farmers. It should be an arid stretch of land. But they take water from a number of sources including underground aquifers and water this large piece of land so that it can produce all manner of vegetables, crops and fruits. However because of the population demands and limited water supply, these two parts of the human system are now competing for this water at increasing levels. In fact this land may have to be abandoned and crops shipped in from else where.
Part of the solution is knowing what to do with water that has been flushed into the sewage system. Stuff that we have used just gets wasted and flushed into the sea. And desalination plants are expensive to build and run and can only really supply sea side towns and cities, because of the huge costs of pumping water inland. Recycling on the other hand can borrow natural filtration systems. They take the water coming from sewage and feed that water through a treatment plant. They then run the water through the ground and into the underground aquifers. They then collect it and run it through a treatment plant again before re-feeding it into the pipework to homes and businesses. It is essentially what happens to water anyway. Its just a system borrowed from nature and put to work by humankind. The engineers who proposed the Californian scheme say that the water is purer than treated rain water.
Desalination plants are another option. However the energy needed to produce the filtered water is enormous. Over the years countries like Saudi Arabia and Australia have built them and made them so that they use less energy than before. But the energy levels are still unsustainable high. It makes the water more expensive for the end user. The costs of pumping water from desalination plants is also high, adding yet more cost to the end user. So without a sustainable energy source desalination plants can only really be used en-mass in two circumstances. One that the water is delivered locally, i.e. to seaside towns and cities. And two if the energy they use comes from a sustainable source.
I think that recycling is the best chance for water security. Because as well as river systems not reaching their delta's anymore, but underground fresh water aquifers are drying up very quickly indeed. It will be a matter of decades before our usage levels outstrip the replenishment from natural sources, if not sooner. If not now. We need an overall, global agreement on water with plenty of funding for engineering project and we need to begin this process now.
