|Diversity, Globalization, and the Ways of Nature (IDRC, 1995, 234 p.)|
|7. Managing planetary thirst|
Water has always been a central element in the history of humankind and its use has frequently had profound social, economic, and political implications. Policies and decision-making in this field can have a great impact on the future of countries and societies. There are many examples in which conflicts over water have been a determining factor in the evolution of countries and societies. The following pages will cover some important or representative basins, illustrating some of the key water issues with environmental, social, and geopolitical implications.
The Amazon basin
The Amazon basin, covering 6.157 million square kilometres, is one of the largest river basins in the world. It is shared by seven countries about two-thirds of the basin (4 million square kilometres) is in Brazil, nearly I million square kilometres lies in Peru, 825 thousand square kilometres in Bolivia, and the rest in Venezuela, Ecuador, Colombia, and Guyana.
The region is characterized by a high annual rainfall - averaging over 2 thousand millimetres - falling during two rainy seasons separated by drier periods. The vegetation is mainly dense rain forest, including extensive wetlands (almost 600 thousand square kilometres). The Amazon region is also home to some of the worlds largest and most diverse ecosystems.
Because the basin is sparsely populated (25 million people, mainly living in the highlands and on the slopes of the Andes, with a density of only four people per square kilometre) and there is plenty of water available throughout, there have been few contentious issues related to the management of its resources. With the growing drive to build dams and the encroachment of mining operations, this situation is expected to change.
The population density of the rain forest itself is very small, as most settlements are situated along the rivers. The major cities of the basin are Manaus and Belem, with about 1.5 and 2 million people respectively; others include Iquitos in Peru and Santarem in Brazil. The river plays an important role in both transportation and fishing. Travel between communities of the basin has traditionally been by boat, although lately air travel has also become important. Land routes are few and, in the heart of the forest, almost nonexistent. Fishing has been one of the main subsistence activities of the population. Thus, contamination of the aquatic bioresources may represent not only a health hazard but also elimination of a source of food and income.
The region is also home to numerous indigenous micronations, which are well adapted to using the forest ecosystems. Although the destiny of these groups is closely linked with that of the water systems, decisions on basin management are usually made without any consideration of their point of view or interests. Land policies in Brazil have traditionally favoured the newly arrived occupant, who can prove possession by burning or logging the forest, rather than native groups who have lived on the land for many generations.
An important drive to occupy the region has been promoted by the building of dams, particularly by Brazil, which is the largest country in the area and has defined hydroelectric dam construction as a national strategy. There are plans to build dams at 43 sites on 13 rivers; they will have a generating capacity in excess of 70 thousand megawatts (Mougeot 1988). This hydro-development drive is to be concentrated in three river systems: the Xingu (32%), the Tocantins (20%), and the Madeira (15%). A number of dams have already been built, both on the Amazon and in neighbouring basins (such as the Parana) with similar characteristics. In some cases, disastrous environmental and social effects have been observed (such as in the Tucurui impoundment on the lower Tocantins).
As a result of deforestation, hydrological regimes are already changing throughout the basin. Droughts and floods, formerly unknown, are taking place along many tributaries, and water quality is being affected by the increasing amount of effluent wastewaters entering the rivers from cities and mining operations.
Contamination from mining is related to the establishment of gold mines. Gold is extracted from ore using mercury or cyanide solutions. (In Brazil, the mercury technique is more common.) Both procedures damage the environment. Cyanide is highly poisonous and mercury becomes concentrated as it moves through the trophic chains and may reach toxic levels in some aquatic organisms that are consumed by the local people. In Japan, mercury poisoning affected the villagers of Minamata Bay in the 1950s, killing 1382 people (Serril 1994). In the Amazon, mercury pollution is particularly serious in the upper basins of the Madeira, Tapajos, and Xingu rivers, and there are indications that widespread poisoning may be taking place in some of the most polluted areas. In the fishing community of Rainha, upstream of Itaituba on the Tapajos, tests on the population showed mercury levels far in excess of the 6 ppm maximum accepted by the World Health Organization. Similar data were obtained in several other locations. In the Madeira River basin, hazardous levels were found in the fish-eating Kayapo communities. Continuing mining operations are expected to increase the environmental and human health effects of mercury contamination further.
With deforestation and indiscriminate occupation, the apparently invulnerable Amazon ecosystem is deteriorating, and this is not only affecting its inhabitants but also the population of the world at large. It will not be easy to address the many issues that are producing these changes in the Amazon basin. New policies will be required in many areas. Land allocation rules and recognition of the land rights of indigenous peoples should be reviewed. Migration to the region must also be checked through adequate policies. The environmental and social impact of hydro projects should be strictly and independently evaluated to ensure that no further ecological destruction takes place. Finally, any strategy will have to take into account not only the interests of the distant industrial metropolises but also the views of the people who live in and suffer most from pollution of the Amazon: the indigenous nations who have managed their land in a sustainable way for innumerable generations.
The Rhine basin
In many ways, the Rhine basin is quite different from the Amazon. Its population density is more than 120 times larger. In a relatively small area, it accommodates more than 50 million people and drains a basin located in seven countries Austria, Belgium, France, Germany, Luxembourg, the Netherlands, and Switzerland. Second, the river is much smaller. It is only 1 320 kilometres long, and it drains a basin of barely 185 thousand square kilometres. As the river flows from the Alps to the North Sea, it crosses Switzerland, France, Germany, and the Netherlands. In this medium-sized basin, there are scores of large cities and some of the most densely populated areas on Earth (such as in Belgium and the Netherlands).
Not only does this river basin have a high population density, but it is also located in one of the most heavily industrialized regions of the world. Most of Germanys output, that of the Netherlands and Switzerland, and an important part of Frances (Alsace and Lorraine) is produced or finds its way through the Rhine basin or its tributaries.
The intensive use of the basin has caused heavy contamination of the river, particularly in its lower reaches in Germany and the Netherlands. In 1985, pollutants in the Rhine at the border of the Netherlands and Germany were measured at the following levels chloride, 1.1 million tonnes per year; phosphate, 3 500 tonnes per year; copper, 450 tonnes per year; cadmium, 10 tonnes per year; and benzpyrene, 1 600 kilograms per year (Maurits la Riviere 1989). The situation grew worse until 1980, but has improved more recently. Currently, the four countries bordering the river are cooperating under the Rhine Action Plan to address the problems of water quality in the river. One of the main strategies to be implemented includes improving industrial processes to reduce the number of contaminants entering the environment.
In addition, there has been a trend toward relocating some of the highly polluting industries to developing countries that have less-stringent environmental controls and cheaper labour (see Chapter 2).
The Nile basin
The Nile basin presents potential management problems that could become litigious issues between countries. The sources of the White Nile and its tributaries are in the African great lakes region, mainly in Uganda, but also in Kenya, Rwanda, and Tanzania. The Blue Nile and the Atbara, which are the main eastern tributaries, flow down from the Ethiopian highlands and provide not only a substantial portion of the water volume but also most of the sediment load. The middle course of the Nile, below the confluence of the White and the Blue tributaries, is in Sudan, and its lower course is in Egypt.
Because the river flows from humid areas (in the south) to increasingly dry areas (in the north), the downstream populations of northern Sudan and Egypt have depended on its water for centuries. In Egypt, where rainfall does not exceed 100 millimetres annually, the Nile is the only source of water. Egypt has a population of almost 60 million, concentrated chiefly along the banks of the Nile; most Egyptian towns and farms are densely packed in the 40 thousand square kilometres of the Niles floodplain.
Any change in the Niles regime could be a matter of life and death for the Egyptians. Currently, an international treaty ensures a minimum flow for Egypt at its southern border with Sudan. Sudan does not use its whole share of water; therefore, problems have not arisen yet.
A potential problem relates to the use of groundwater near the river. In northern Sudan and southern Egypt, the river crosses the Tertiary sedimentary basin of Nubian sandstone, which contains a large and relatively unstudied aquifer. An important portion of the water recharging this aquifer comes through infiltration from the Nile. Any large-scale use of the aquifer may result in a reduction in flow downstream. It will be difficult to control Sudans use of the aquifer, as the relation between groundwater and surface water use has not been firmly established. Recent problems in multiethnic Sudan have prevented its inhabitants from increasing their use of water for irrigation.
Another potential problem for Nile communities is the proposed draining of the Sudd wetlands with the construction of a 360-kilometre canal (the Jonglei Canal) and other related waterworks. The Sudd region of southern Sudan is an area of high biodiversity that not only regulates the flow of the White Nile, reducing the risk of catastrophic floods and droughts, but also provides abundant resources to the Nuer, Dinka, and other peoples who have lived in the area for many generations. The continuing state of war in southern Sudan has forced the project to be abandoned, and it is unlikely to be completed in the near future.
Similar problems may arise in Ethiopia, where the Blue Nile and the Atbara rivers arise, providing 85% of Egypts water. Egyptians are concerned about the possible future construction of dams for power supply or irrigation in the upper basins. Political instability in Ethiopia has made any large-scale hydro development impossible, but this situation may change in the future. There have been talks regarding the construction of a dam on Lake Tana, the source of the Blue Nile, and this may affect Egyptian control of Nile waters (Pearce 1991, p. 36).
A more real and pressing problem in the Ethiopian highlands is the widespread destruction of the forest or shrubby ecosystems in the upper basins. River regimes have become much more extreme, with extended droughts punctuated by periods of increased runoff. Intense erosion of the basin soils has caused a considerable increase in the solids content of the water and silting effects downstream. The Aswan Dam has been particularly affected by increased silting, which has reduced the length of its usefulness to merely a few decades.
The Aswan Dam in upper Egypt was completed in 1970; its inauguration allowed the opening for agriculture of extensive formerly arid lands. Apart from its initial positive impact on agricultural production, however, the dam has had a number of negative effects. One relates to conditions necessary for agriculture on the floodplain downstream from the dam. Because the dam has reduced the amount of silt reaching the plain, artificial fertilizers are required, increasing costs and affecting the water quality of the river. The newly irrigated soils have also been waterlogged, and salinization of soils and groundwater has become a common problem. Human health was affected by an increase in schistosomiasis. Construction industries suffered because they depended on a supply of alluvial silt to make bricks. Brick-makers often compete successfully with farmers for the same land. As a result, traditional farming areas have been reduced along with agricultural production.
The Nile basin is a fragile hydrographic system requiring careful management. Much coordination will be necessary to ensure that it is used appropriately and sustainably. However, management of such a complex and multinational basin is not merely a scientific endeavour. It encompasses political, social, economic, and historic issues. Only a holistic approach will permit resolution of its long-term problems without conflict and allow its optimum use to improve the quality of life of its population.
The Jordan River basin
Although the Jordan is a small river, it is located in an area where water resources are extremely scarce because of low precipitation (ranging from less than 100 millimetres in the south to about 500 millimetres in the northern highlands) and a history of acute political conflict between the countries sharing its basin (Lonergan and Brooks 1994).
There are five countries in the basin: Israel, Jordan, Lebanon, Palestine, and Syria. The upper basin is mainly in Lebanon and Syria, where the Hasbani and Banias rivers, together with other neighbouring springs in Israel, feed Lake Kinneret (the Sea of Galilee), which has a volume of 4 billion cubic metres. The main outlet from this lake is the Jordan River, whose waters are shared by Israel, Jordan, and the Palestinian West Bank. The total annual flow in the river brings 611 million cubic metres of water into the Dead Sea, whose salinity is 250 thousand ppm, or seven times that of seawater. To further complicate the political aspect, a considerable portion of the water flows underground (some toward the river valley and lakes and some toward the Mediterranean), increasing the chances for conflicts.
In an international basin such as this one, environmental management must be based on water-management policies and strategies. Every human activity depends in one way or another on the decisions that are made regarding water. Solving water issues in this part of the world will probably be the first step toward a lasting peace.
The Aral basin
For a long time, the Aral Sea in central Asia was the fourth largest lake in the world, with a unique ecosystem that had evolved in isolation for many millions of years and contained a diverse flora and fauna in its 50 thousand square kilometres.
During the early 1960s, the Soviet government implemented a mammoth irrigation project to grow cotton using water from the Syr-Darya and Amudarya rivers. The project affected, directly or indirectly, the republics of Kazakhstan, Kirghizia, Turkmenistan, and Tajikistan. Unfortunately for the surrounding communities, the volume of the lake depended almost exclusively on water from these two rivers. Their flow was substantially reduced as water was diverted to cotton plantations. The amount resuming to the rivers and the lake was, and still is, only a fraction of the previous volume and was heavily loaded with agrochemicals. After three decades, the Aral Sea is dying. Its ports are more than 80 kilometres from the lakeshore, its marshes and forests have perished, and the aquatic ecosystems have shrunk and lost much of their biodiversity (Pearce 1994a). The volume of water in the sea is only 40% of what is was only 33 years ago. Its volume continues to decrease by 27 cubic kilometres every year, the surrounding aquifers are drying up, and, in about 20 years, the sea is expected to disappear completely (Pearce 1994b).
The unsustainability of the model is clear. The cotton fields are waterlogged and the soil is becoming salty. There are almost no fish left in the lake. In some communities (such as Nukus), the water is unfit for drinking. Despite general agreement of the part of the various interested states that the situation must be improved, no targets or timetables have been set for doing so. In light of the current economic situation in the basin countries, it is doubtful that corrective measures will be implemented in the near future.
The Chad basin
The Chad basin is an endoreic hydrographic system extending over about 2.7 million square kilometres in the western part of central Africa. The northern portion of the basin lies in the semi-arid and arid regions of the Sahel and Sahara. The southern and eastern sections are mainly in the savannas of Sudan, Cameroon, and central Africa, although it occupies forested areas in the south. The basin is shared by several countries, of which the largest is Chad. It depends on the basin for most of its agricultural production and fisheries. The centre of the basin is occupied by a water-filled depression whose area varies with rainfall - Lake Chad.
The main rivers of the basin are the Chari and Logone, flowing from the highlands of Cameroon and the Central African Republic. These systems are, by far, the greatest suppliers of water to Lake Chad - 28 billion and 12 billion cubic metres per year respectively. These rivers flood their alluvial plains (the Yaeres) and the shores of the lake annually. The actual flooded area is estimated to be about 59 million hectares. The variations in the hydrological regime of the Logone River are important; at Baibo-Koum, a maximum flow of 4 438 cubic metres per second and a minimum flow of 13 cubic metres per second have been observed.
The Yaeres are the breadbasket of the Chadian region. Rice is cultivated using the floodwaters, and millet is planted in drier areas or after the floodwaters recede. Animal production is carried out in association with farming activities using itinerant strategies. Over 100 thousand animals are brought to the Yaeres annually to graze. Chadians also harvest an average of 80 thousand tonnes of fish annually from the basin.
In the 1960s, a large development project with international funding was proposed for the widespread irrigation of the Chad lowlands: the South Chad Irrigation Project. The project was to use the water to green the surrounding deserts. Planning began in 1962, at the end of a period of unusually high rainfall. According to one designer, the project was a disaster. The hydrologic study was carried out over only 3 weeks, the idea of securing a different source of water was dismissed out of hand, and it was assumed that the project was designed to operate for all water levels in the lake. In 1992, the intake areas were dry and many rotting ships were littering the landscape, often more than 60 kilometres from the lakeshore. As well, 4 thousand kilometres of canals were permanently dry and some villages that were flooded in 1962 were almost 100 kilometres from the shoreline.
This situation is not expected to improve over the medium or even long term. The lake loses 2 metres of water through evaporation every year and the flows of the Logone and Chari rivers have been cut in half. However, it is important to remember that in this case - as in many others - the problem does not lie in the natural variations of rainfall or in the high level of evaporation; rather, it lies in the manner in which the project was conceived, designed, and implemented and in the unnatural and nonparticipatory view of development that inspired the project from its inception.
The Colorado River basin
The Colorado River (Figure 2) rises in the Rocky Mountains and flows down the west face of Longs Peak, almost 4 thousand metres, as it begins its 2 400-kilometre journey to the Pacific Ocean. It receives runoff from the western areas of the Colorado, forming the Grand Valley where the first large irrigation developments are located. When the river enters this valley, its salinity is only 200 ppm; as it leaves the area after irrigating its crops, the salinity averages as much as 6 500 ppm.
Farther downstream, the river is joined by the Gunnison and the Green tributaries before forming the Powell reservoir behind the Glen Canyon Dam. Several new tributaries join the Colorado below this dam (Little Colorado and Virgin), increasing the flow, which is again dammed farther downstream forming several artificial lakes: Lake Mead above the Hoover Dam, Lake Mojave at the Davis Dam, and Lake Havasu at the Parker Dam.
The river then receives the brackish water of the Gila River, which increases its salinity slightly until it reaches one of the largest interbasin water-transfer operations in the world, the aqueduct to California, where one-third of its flow is pumped westward. The water is channeled into the Imperial Valley, Los Angeles, and San Diego to satisfy the needs of thousands of Californian farmers and millions of urban dwellers. Many of the fresh winter vegetables in the United States are produced using Colorado waters, and at least half of the water consumed in greater Los Angeles, San Diego, and Phoenix comes from the Colorado.
Only a small proportion of poor-quality water is left in the river when it finally crosses the Mexican border. To solve critical binational problems, a treaty was signed with Mexico in the 1970s to ensure better-quality water in the lower reaches of the river. Recently, the US Congress approved investments in equipment for salt removal at a Yuma plant. It will cost $300 per unit to desalinate water that irrigators buy for $3.5 per unit upstream.
Figure 2. Dams and reservoirs of the Colorado River.
As will be described in Chapter 12, the Colorado River has been changed considerably, and not necessarily for good reasons. Today, the river is largely an artificial system; aquatic life has been affected both in the river and in the Gulf of California; its flow has been curtailed; and its aquifers have been directly or indirectly modified, reducing the sustainability of the systems. The model of the Colorado River is another example of inadequate and nonparticipatory use of natural resources. We can only hope that the 21st century will see some of the worst effects of these pharaonic, 20th century hydroworks undone.
The aquifers of the western United States
Similar problems of widespread and thoughtless interference with nature can be observed in the aquifers and basins of central California. At the beginning of the century, almost all of Californias water came from groundwater sources; now the proportion is 40%. The farmers of the central valley (Sacramento and San Joaquin valleys) overused the water and, by the 1930s, the farming economy was approaching collapse. The farmers convinced the legislature to authorize the Central Valley Project, by far the largest water project in the world; it was partially financed by the Roosevelt government. In the 1960s, the California Water Project, of similar size, was implemented. Together, these projects provide eight times the amount of water needed for the city of New York.
Despite the additional water, however, overuse continued because, instead of merely substituting the new sources for the older, over-exploited sources, farmers opened up more land for cultivation. Estimates of the amount used over the renewal capacity of the aquifers in California range as high as 3 billion cubic metres per year, causing a growing water crisis throughout the state.
The lack of regulation pertaining to groundwater pumping, a traditional absent feature of the California legal system, has probably been a major factor contributing to the current critical situation (see box 6). However, cases of overexploitation of groundwater resources are not restricted to California or the United States. They can be found worldwide from the valley of Mexico to Bangkok, and from Manila to Havana.
6. The Ogallala aquifer
The Ogallala aquifer is one of the largest and most heavily used groundwater reservoirs on Earth. Most of the water for irrigated farming in Texas, Kansas, Colorado, Oklahoma, New Mexico, and Nebraska comes from this huge underground basin. Continued overextraction has gradually reduced pressure in the aquifer - wells are no longer artesian, water levels have dropped, and pumping costs have increased. Lately, awareness of a vanishing resource has raised questions about the need to respect limits of renewability to protect the water resource.
Traditionally, sustainability of groundwater was not a concern in the US midwest. An example of the philosophy inspiring groundwater policy and decision-making in the field of resource management during the 1950s and 1960s (and today in some cases) is supplied by Felix Sparks, former head of the Colorado Water Conservation Board. When asked about the future of groundwater in the state, he responded with a rhetorical question: What are you going to do with all that water? Leave it in the ground? The state engineer in charge of water in New Mexico (Stephen Reynolds) further illustrated this line of thought: We made a conscious decision to mine out our share of the Ogallala in a period of 25 to 40 years (see Reisner 1986).
According to this approach, the solution to water scarcity was more water projects, including some that were very expensive and resulted in returns as low as 5% in economic benefits.
In Reno, Nevada, gambling and prostitution are legal, but for a long time water-metering was against the law.