Every time I go down the La Vigie- Nouvelle France road on my way to Plaisance Airport I cannot help feeling a little mad and very sad and very worried at the destruction of vast areas of the natural vegetation to make way for residential development. The first time that I saw what had happened I was flabbergasted. I could not believe that no one had warned Government of the danger to our land and water resources of the uncontrolled destruction of the natural vegetation of our central plateau which is the main catchment area of our reservoirs and rivers. Lots of questions came to my mind. Had the advice of land and water resource specialists been sought and if so why was it not heeded? Did the technical ministries concerned tender their advice even if they were not asked? It is inconceivable that such a thing could have happened without any of the relevant government institutions making their views known. It is all the more surprising that no questions were asked as even laymen know that changes in the natural vegetation affect the hydrological behaviour of the soil. It appears that crude economic or rather financial considerations must have dictated the decision.

Many people believe that land that is left to natural vegetation is wasted or underutilized. They do not realize that far from being of no economic value, the natural forests and vegetation on the central plateau are essential for the regular and continued supply of one of our most precious resources: water. Contrary to popular belief, forests do not attract rain, but they play an essential role in the conservation of water. A little hydrology will enable us to understand how. As rain falls on natural vegetation, the leaves and the grass break the speed of the rain drops and the roots break the soil and provide natural channels for the water to infiltrate the soil. Thus natural vegetation facilitates the absorption of water by the soil. When the layer of soil just below the surface, called the sub-surface, is saturated, the water starts accumulating on the surface and, if there is a slope, runs down the slope causing surface run-off. If there is sufficient rain, the water penetrates further into the ground and forms ground water. When the ground water reaches impermeable soil or rock it starts accumulating and becomes underground water. Underground water runs down the rock formation to create underground rivers that may eventually come out lower down as a source or produce marshes or end up in the sea. Sub-surface and ground water act as reservoirs that slowly release water into rivers and lakes after the rain has stopped, thus ensuring their perenniality. Without sub-surface and ground water rivers would just dry up soon after the rain stops. Underground water is a natural reservoir of water which can be tapped for domestic and other uses. In Mauritius it provides over 50% of the water used for domestic purposes.

Urbanisation results in the replacement of forests and vegetation by buildings and roads i.e. concrete and tarred surfaces. The hydrological consequence is that as rain falls it simply runs off these surfaces and, depending on the topography of the land, accumulates or flows down natural slopes into rivers and drains, causing floods if the rainfall is heavy. Thus the natural processes of infiltration into the soil and of the recharging of the ground and underground water reservoirs are considerably impaired. As a consequence of this the amount of water that is stored in the ground and discharged later into rivers and lakes is considerably reduced thus resulting in lower volumes of water in rivers and lakes and, in severe conditions , even to their drying up. This is what has happened this year in Mauritius. We have had a lot of rainfall during the rainy season and we were told that all the reservoirs were full and then a few months later we were informed that there would be interruptions in the water supply because the levels in the reservoirs were low.

Water shortages, as we all know, can have very serious economic and social consequences. The recent event in Palma is an indication of what popular reaction might be. It conjures up apocalyptic visions of people rioting and burning to voice their anger for the lack of such a basic necessity as water. Our people are not like the peoples of the Sahel region who would just sit down and die while waiting for international aid. Should such a situation arise no economic development would be possible; it would even be difficult to maintain the present level of economic activities.

Many of the land developments that have taken place recently, like those on the central plateau, in the Ebene region and some of the IRS projects constitute a real danger to our water as well as our land resources. Apart from the hydrological consequences that I have described above, there is going to be more erosion destroying the land and causing silting in rivers and reservoirs. It is high time that the State should take its responsibilities. By the State I do not mean just Ministers but top Government officials, Heads of the specialized Government institutions and public and publicly funded research institutions. The State cannot be dictated by the selfish interests of the property developers for whom every square metre of land has to be commercially exploited. We cannot allow the greed of a few to override the welfare of the many.

I would suggest that Government should immediately stop all deforestation and destruction of natural vegetation and set up a Standing Committee on Land and Water Resources comprising the relevant Government, private sector and non-government organizations in order to ensure a more judicious use of these resources to meet our present and long term needs. The official Opposition Parties should also be involved as there should be a national consensus on this issue. I was going to suggest a Land and Water Commission that would be completely independent of politics and politicians, but people might exclaim: ?Not another Commission!? There was once a Land Commissioner but it was a one man institution; obviously it was not meant to function and did not last long. We have to take things more seriously if we want to achieve something?

I remember once telling a very Senior Minister that the location of a dyeing factory on the central plateau was dangerous for our underground water. He looked at me and said: ?Piti, pas gagne letemps pou guette tout sala; sa nou a guette plis tard.? A few years later the factory was moved down to the coast ; in the meantime, the water that was being pumped from a borehole a few kilometers down had turned slightly pink. We were lucky that the underground water had not become unfit for human consumption, as has happened in many countries.

The present situation is much more serious than what happened forty years ago as much vaster areas all over the island are concerned. If we do not take corrective measures immediately we shall be heading for disaster.

<B>Kumara VENKATASAWMY</B>