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GENERAL CONSIDERATIONS
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WORKING PAPER
0. The inventory of the World’s freshwater resources, that was examined during the special session of the United Nations General Assembly in New York in June 1997, has just confirmed that should the present schemes of water resources use continue, almost two thirds of humanity might suffer from a moderate to serious water shortage before year 2005 as compared to one third at present.
1. " Human beings are at the centre of the concerns for sustainable development: they are entitled to have a healthy and productive life in harmony with nature " (Rio Declaration).
2. The objectives of Sustainable Development are:
- to fight against poverty,
- to ensure social advancement,
- to favour economic activities,
- to protect the environment
3. Water is one of the main vectors for Sustainable Development, for which the international community became aware of existing problems, in Rio in 1992 and in Noordwijk in 1996. They concern more precisely:
- the reliable meeting of urban and rural populations’ requirements for good quality drinking water in order to improve hygiene and health and to prevent large outbreaks of disease,
- the agro-food self-sufficiency for local, regional and world populations by ways of a sustainable development of agricultural productions that rely on an appropriate irrigation in particular,
- the harmonious development of industry; energy production, leisure, and, in some sectors, tourism and waterways shipping,
- the increase of fish farming for food purposes,
- the prevention and control of pollution of all kinds and origins in order to ensure the optimal reuse of the resources and the preservation of the biodiversity of ecosystems.
- the prevention of natural disasters and erosion, flood or drought hazards, while taking into account water and ecosystem management,
4. All problems thus posed cannot be dealt with either in a sectoral or localized manner, or separated from one another.
5. Today, the increasing consumption and pollution may lead to difficulties in the use of some resources that are nevertheless available in sufficient quantities, and water may become, in the coming decades, an essential factor limiting economic and social development, as it is already the case in some arid countries.
6. A global and integrated water resources management is therefore needed.
7. The large watersheds or aquifers are the natural and relevant geographic units to organize such a sustainable water management.
A - RESOURCE IS SCARCE, IRREGULAR AND POORLY DISTRIBUTED
8. Although, water is abundant on our planet in all forms, most of the stock is constituted by sea water and ice; inland liquid freshwater is paradoxically globally scarce, the main stock being groundwater.
9. Not considering fossil groundwater, renewable freshwater resources are integrated into the " water cycle " and run off into a flow that is limited in the absolute by the rain volumes that fall on each continent and that progressively return to the oceans where it evaporates.
10. · The distribution of these resources among continents and countries, even among the regions of a country, is highly unequal.
11. Their flow may vary from 1 (Australia) to 15 (South America) when only emerged land is considered. The huge Amazon River basin alone accounts for 15 % of the global flow.
12. There are obviously very big differences in the situation between arid and semi-arid areas, that may be crossed by relatively large rivers, and equatorial and tropical areas or even areas with an oceanic climate crossed by a dense and ramified hydrographic network.
13. On some islands and in arid countries, the use of brackish or sea water desalination has already become a necessity, together with the intensive reuse of treated wastewater for irrigation and groundwater recharge.
14. It should also be noted that more than 215 large international water courses have been counted over the world and their catchment areas cover more than 47 % of the emerged lands.
15. · Resources have shown to be highly irregular over the years and vary greatly between the seasons in a year.
16. The flow rate of watercourses greatly varies depending on the season, and the meaning of a yearly flow rate figure is thus fundamentally different according to the river regime and whether this regime is natural or regulated.
17. In keeping with this idea, a large part of the water volumes may flow during floods and these volumes usually cannot be entirely contained in reservoirs when they exist. This part of the flow cannot possibly be controlled and managed, and might even become a vector of flood disaster. However, in arid areas, flood spreading can be beneficial for local farmers who most often can optimally control it.
18. On the contrary, the occurrence of several successive dry years or merely lower than the average may cause scarcity, or even drought or starvation in some regions that are usually supplied with water in an appropriate or at least tolerable way.
19. Besides, additional scientific assumptions regularly confirm the hypothesis that the climate might not be stationary, but that we could be in a period of climate change, characterized by global warming up with significant effects on the water cycle. Faced with such uncertainty, we should think carefully and take into consideration the fact that the future state of the water resources of a region or a country will not necessarily be the same as today.
B - HUMAN ACTIVITIES HAVE GREATER AND GREATER IMPACT ON RESOURCES AND THE ENVIRONMENT
20. Some developments, excessive withdrawals or discharges cause a change in the natural regime of watercourses, the degradation of resources quality and the disruption of ecosystems.
21. Water consumption was multiplied worldwide by a factor close to 7 since the beginning of the century and has doubled during the last 20 years.
About half of this increase is caused by population growth, which poses the problem of demographic growth control in areas where resources are scarce.
The other half, results from the per capita consumption linked to agricultural and industrial development and to a better social well-being with the rise of local problems of resources allocation for the different uses.
22. The over-exploitation of some aquifers has led to their salinization in coastal areas or too high contents of polluting substances, and that of watercourses may have caused their drying up, during certain periods, with consequences on aquatic fauna and ecosystems that are sometimes irreversible.
23. Point or non-point pollution discharges, especially the badly controlled use of fertilizers and pesticides, have adverse effects on human health and, in many cases, prevent the reuse of all or part of the water volume that is otherwise sufficient for other uses.
24. It is also indisputable that there is a close correlation between water resources and town and country planning:
25. - in rural areas, excessive land reclamation, overgrazing, change in crops or vegetal cover and in plot structure or agricultural techniques, as well as the harnessing or regulation of river and stream bed, have consequences, sometimes very serious, on the change in local climate, evaporation, erosion or on the change in flow regime that may lead to floods or droughts or to pollution, with suspended solids in particular : the soil-water pair cannot be dissociated and balance disruption causes significant dysfunctions;
26. - in urban areas, soil sealing through buildings or infrastructures also causes significant disruptions, especially in periods of heavy rainfall.
27. Evaporation in large man-made reservoirs also represents a very significant part of the consumption of available resources.
28. In some regions, a poor control of the water supplied to plots and lack of drainage have caused the neutralization of a large part of irrigated areas through salt intrusion.
29. In the Mediterranean Basin, where prospective studies have been carried out, the per capita water resources/populations ratio (1995) has shown levels of water abundance or scarcity in countries. They range from extreme scarcity (less than 100 m3/year/inhabitant) in the Palestinian Territories/Gaza and in Malta, to over abundance (more than 10,000 m3/year/inhabitant) in Albania and Ex-Yugoslavia.
Eight countries, whose total population reaches 115 million inhabitants, are already under the threshold of 1,000 m3/year of natural resources per inhabitant (yearly average), a situation in which stresses appear between needs and resources, especially when irrigation is necessary. In six countries (with a population of 28 million inhabitants), resources fall under the absolute " scarcity threshold " of 500 m3/year of resource per capita: Israel, Jordan, Libya, Malta, the Palestinian Territories, Tunisia. Besides, almost all natural renewable resources are already exploited, even over-exploited, in these countries.
The " final water consumption indexes " might exceed the 100 % threshold in 2025 in seven countries of the Mediterranean Basin, as an optimistic estimate, thus representing either intensive reuse, or the use of non renewable or non conventional resources, such as brackish or sea water desalination. Thus, Libya reaches a stupendous index that exceeds 2,000 %, the demand being met at more than 90 % by the exploitation of fossil water. In Israel, Jordan and Gaza, the meaning of these indexes should be mitigated by progressively resorting to wastewater reuse.
C - A CONCERN FOR THE FUTURE
30. Although local situations are obviously very diverse and sometimes contrasted worldwide, some constants do appear:
31. · Flood control, with possible high risks for population safety, remains a concern, as are seasonal or multi-annual droughts
32. At present, the rate of surface water resources regulation by existing dam-reservoirs already reaches high levels and many sites that were economically favourable to the construction of regulation-dams have already been used, at least in the best equipped countries.
33. Too many existing reservoirs have their regulation capacity already irremediably limited by quick siltation, by sediment coming from the erosion of upper basins, due to lack of adequate control of the vegetable cover of land.
34. · Irrigation is the biggest consumer of water, about ¾ of the total requirements and irrigated areas continue to increase rapidly, due to:
- imperatives of food security, especially in the developing countries with high demographic growth,
- policies for controlling the rural exodus towards the big cities and for maintaining the populations in rural areas,
- the need to intensify production on the most productive lands and to protect marginal lands.
35. In many countries, the irrigation techniques used are still traditional and lead to very significant losses in water resources, either upstream through evaporation in lake-reservoirs and open canals, or in plots through infiltration and loss into the ground of most of the water used and which therefore benefits plant growth for an approximate worldwide average of only 1/3.
36. Thus, the overall efficiency of irrigation systems (ratio between, on one hand, the water quantities that are really lost through evapotranspiration of irrigated crops and, on the other, the water quantities withdrawn) is not well known and controlled. It greatly varies and potential water savings are considerable. They constitute a significant economic and environmental challenge, although the water lost through infiltration recharges groundwater downstream.
37. • Globally domestic water demand is rising rapidly, as is that of industry, energy production and other economic and leisure activities. This is starting to raise problems for resources allocation.
38. At the beginning of next century, 50 % of the world population will live in cities and an increasing part of about 10 % will be concentrated in huge " megalopoles " of more than 10 million inhabitants. It is obvious that the issues of drinking water supply and sanitation will be the most acute in these very big cities although consumption seems to be at a standstill or even decreasing for certain uses in some industrialized countries: the problems are exacerbated in underprivileged districts.
39. The same will occur in many medium and small towns and on islands.
40. Many villages also face serious difficulties and, too often, have no access to water.
41. Too large a part of the world population has still no access to water and lives under non hygienic conditions. Too many people are still victims of water-borne diseases.
42. Human health hazards are still found in available or supplied water, inclusive of some large urban centres.
43. Losses in community water supply systems in towns may reach a worldwide average of 50 %.
44. Great delays are found in the treatment of wastewater before its discharge into the natural environment and the operation and yield of many installations, when they do exist, are not sufficient.
45. · The recycling of process water and the control of polluting emissions in industry are still uncertain.
46. In a general manner, the main problems to be solved arise, on one hand, from a poor efficiency of water uses, and, on the other, from pollution produced by human activities.
47. The serious difficulties encountered do not mainly come from an insufficient number of technological solutions, although a better adaptation of techniques to local situations is advisable, but first from an insufficiency in institutional and economic organization, from lack of or non compliance with regulations and standards, lack of appropriate training for professionals at all levels and of all specialities that must intervene, as well as for the various water users and from the insufficient education of the population.
48. The water sector is also highly capitalistic and improvements will require the mobilization of very large investments that the public budgets will not be able to meet alone. A larger and larger involvement of users in water management and funding is unavoidable.
49. Besides, due to lack of capacity for management, operation and maintenance, many installations do not reach their nominal efficiency and deteriorate too rapidly thus requiring costly rehabilitation.
It must be pointed out that recurring operating costs are usually, in modernized services, in the same order of magnitude as investment amortization: they must be sustainably ensured.
50. Knowledge of water resources, uses, discharges as well as of the functioning of the environment remains truly insufficient to enable a global and sustainable management.
51. In order to prevent risks of degradation of the situation, it is necessary to mobilize the whole international community around ambitious but realistic objectives, to coordinate our efforts and to change scales in the prevention of problems, in order to enable:
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