Before he left office, the secretary-general of the UN Boutros Boutros-Ghali predicted that the next world war would be fought not over oil, gold or land, but over what investors now describe as the world's most valuable commodity . . . water. Already, there have been a few minor 'incidents' on the border between Malaysia and Singapore, where a vast network of water pipes from Malaysia keeps the citizens of the former British colony alive courtesy of their neighbours . . . for now.

Already dubbed 'blue gold', the UN has declared the next 10 years the decade of water.

Is there enough water in the world?

"Water, water everywhere, nor any drop to drink." Over 150 years ago, English poet Samuel Taylor Coleridge in his poem 'Rime of the Ancient Mariner' unwittingly predicted the looming crisis.

Three quarters of the world is covered in water. But just 3% of that is fresh water and two-thirds of that is trapped in ice caps, leaving less than 1% available for the six billion people in the world. Worse, not only is the world's population increasing rapidly, but water consumption per head is doubling every 20 years. Jacuzzis, washing machines, multiple bathrooms, etc, means that people in the developed world consume around 800 litres of water per day, while those in developing countries consume around 75 litres. When, not if, the demand for water from the developing countries reaches the level of consumption in the developed world, the supply will dry up. That is when the trouble will start. In the world's most rapidly developing economy, China, two thirds of its cities already suffer from water shortages.

What about Ireland?

Despite being an island nation and the perception that it never stops raining, Ireland is no better off than any other western country. The problem is that while we have lots of rain, we don't have the technology to catch it.

Also, getting water to the highly populated urban centres is the key difficulty. A few weeks ago, Dublin City Council caused a stir when it suggested that it may have to build a pipeline to Shannon to access water for the burgeoning population in the greater Dublin area.

Who uses the most?

It is hardly a shock to find that the US is the biggest consumer of water in the world.

Total aggregate daily water usage per capita in the US is 3,925 litres while in Europe it is roughly half that at 1,987 litres. Africans use just 598 litres each.

Who are the water users and wasters?

Globally, agriculture uses 70% of the world's available water supply, industry takes 22% and domestic users consume just 8%. It takes 100,000 litres of water to produce one kilo of beef, 3,500 litres to produce a kilo of chicken and 1,000 litres to make 1 kilo of rice.

But in the developed countries, industry takes the largest slice (59%) of the available water.

Leaky pipes are one of the biggest water wasters in the world. In eastern Europe and central Asia 35% to 50% of the drinking water is being lost through leakage. In your own home, a small drip from a tap can waste as much as 75 litres a day.

What can we do?

One of the major problems with water is that its supply is finite. The same amount of water is trapped in the atmosphere and our ability to catch what we need is being depleted by pollution.

Desalination plants, which extract the salt from sea water to produce drinkable water, are an increasingly popular solution. But such plants take an awful lot of another natural but rare resource to run them . . . oil . . . which explains why they are such a popular solution in the oil-rich countries of the middle east. But in the west, it is a bit like robbing Peter to pay Paul. Also, the salt residue left behind after the process is a major pollutant.

Are we doing it?

Significant investment will have to be made in water infrastructure including research, investment in treatment plants, pipe networks, dams and reservoirs in an ongoing effort to maximise the tiny fraction of water we can get from the atmosphere to slake the thirst of our growing population.

Already, traditional filtration treatment plants which use chloride are being replaced by plants which clean water using ultraviolet light.

How much will this cost?

Billions. In the US it is estimated that it will cost $150bn to upgrade/replace the existing water infrastructure just to comply with safe drinking water laws. India wants $3.2bn from the World Bank for water projects. In Ireland in the last three years alone, the government has spent 1.5bn on water services.

Who is going to pay?

You are. Some years ago, Geoff Read shocked the nation when he persuaded the Irish to actually pay for drinking water called Ballygowan in a plastic bottle which hitherto was freely available from a tap. It is not such a leap to charge consumers directly for the amount of water they use, particularly as the current cost of water is taken indirectly from Irish taxpayers.

Aware no doubt of the political ramifications for each member state, the EU's current policy is to try and persuade each state to adopt the 'let the user pay' principle. The theory is that by charging for it, people will cut down, which in turn will help reduce the shortage.

Last week, the ESRI said that people do not appreciate the real value of things they don't pay for and the government should impose water charges.

Who benefits?

Last week, the Belgian-based asset-management company KBC spoke enthusiastically about the huge gains to be made from investing in water technology companies, desalination plants, pipe manufacturers, etc.

But in order to attract investors, water will have to produce increasing streams of revenue and that means people will have to pay up. KBC's chief economist, Eoin Fahy, admitted that while it is not up to the economists, water charges will be a reality in Ireland within the next five to 10 years.

Is water a good investment?

As KBC has pointed out, water supply is finite, in short supply, irreplaceable, and essential for life. That makes it a very valuable commodity.

Almost as valuable as the air we breathe.

But let's not get ahead of ourselves . . . yet.