KAWA MULTIMEDIA PUBLICATIONS
Introduction
These are river dam projects set up using financial and technical assistance from developed countries aimed at solving a number of problems in an area ad leading to the development of the area. They are called multi-purpose because they are designed to produce more than one benefit, which can increase the country’s and improve on the standard of living of the people.
Various multi-purpose development schemes have been set up in Africa. They are essentially aimed at controlling the flow of rivers, reducing floods, and solve other problems that affect the life of the people. Such problems include floods, famine, shallowness of the water, as well as pests and diseases.
A multi-purpose scheme therefore, aims at solving the above problems. According to the modern geographical analysts, ”a large dam with a man made lake behind it can provide the answer to most if not all these problems”. That is what multi-purpose development scheme is all about whether in Africa or else where in the world.
However, as the construction of such projects takes place more practical problems are created. Such problems include: displacement of people; the occurrence of water snails which cause bilharzia; flooding also affects some villages.
The control of Africa's rivers is, arguably, of greater lasting importance than the discovery of oil or precious metals. The rivers will be there long after these have gone; and so will the benefits they bring when they are controlled. Water can provide power for industry and it can make crops grow where none grew before. Rivers can provide this water, but sometimes they do not. Often they nearly dry up and then at other times they flood uncontrollably. The water rushes uselessly out to sea, leaving dry lands without crops, industry without power and countries remain poor. Water can provide even more because fish grow in rivers and, being a source of protein, are a valuable food. In many countries people suffer from a protein deficiency because meat is too expensive. A fishing industry could supply this need; but fish cannot live in any quantity in rivers which sometimes dry up. Many countries would benefit greatly from an efficient and regular riverine transport system; but boats and barges can only sail on rivers which have no rapids and which do not dry up. Large and valuable deposits of minerals remain unexploited because there is no power supply available.
'A large dam and the man-made lake behind it can provide the answer to most, if not all, of these problems.'
That is what multi-purpose river development is all about, whether it is in Africa or elsewhere. The hydro-electricity which is produced by these dams tends to receive most publicity, but many of the other results are also of great importance. River development does not bring only benefits, but problems as well; however, generally speaking the good things tend to outweigh the new problems that may arise.
Africa has tremendous potential for river development, including H.E.P. The Aswan Dam is one of the.better known examples and will be dealt with in more detail later, together with Lake Nasser, the man-made lake which has grown up behind it.
Most of the potential lies south of the Sahara where many large rivers flow through the very narrow gorges they have cut as they plunge off the multi-stepped high plateau regions on their way to the sea. The River Zaire must have the greatest potential of them all, if you include the many huge tributaries which flow into it from north and south.
It is best that the market for hydro electricity should not be too far away from the dam site because a considerable percentage of the power generated is dissipated and lost if it has to be transmitted over long distances. However, this is not essential if a site is excellent for building a dam and for the creation of a man-made lake behind it.
It is even less important, as we shall see, if the reasons for building the dam are based on political considerations as well as economics.
First of all then, let us look briefly at one or two of the less well known examples of river control; examples which may, perhaps, receive greater recognition in a year or two's time.
The River Zaire has the greatest potential of all Africa's rivers and one of the first of its projects is to be found at Le Marinel in Shaba province where the N'Zilo Dam produces power for the copper mines from the headwaters of the River Lualaba as shown in Fig. 84. The lake, which is now nearly 100 kilometres long, provides fish for nearby towns like Kolwezi. The Inga Dam shown on page 103 now produces 1200 megawatts from the rushing waters of the Inga Falls near Matadi for the power hungry region between Kinshasa and the coast. Soon the second phase will be finished, while another dam in the Kisangani Falls region will supply Kisangani and its growing industries with a further 350 megawatts.
Further south on the Angola-Namibia border is the River Kunene where a combined H.E.P. and irrigation scheme is being built. Financed by South Africa it has, unfortunately, suffered many interruptions because of civil war in Angola and the struggle for independence in Namibia. The River Cunene (Kunene in Namibia) has tremendous hydro electric capacity and, all told, it is planned to build seventeen dams along its length which will produce 2400 megawatts. As well as the power, the irrigation potential for both countries is enormous. However, the plans so far call for three dams. One, a long way up stream at Gove is just a storage dam and was completed in 1973.
The other two dams are at Calueque and Ruacana and are virtually completed. The Calueque Dam has a dual purpose in that it will store water and control the flow to the Ruacana Dam and also pump water along a 130 kilometre irrigation canal to Oshakati in Ovamboland. Forty kilometres downstream from Calueque is the Ruacana Falls Dam where a 240 megawatt underground power station has been built, with room to add a further 80 megawatts. The power station is in Namibia and water is diverted from the Kunene along a headrace tunnel which has a 100 metre vertical drop to the generating plant, before being led into the tailrace on its way back to the Kunene.
Unfortunately the initial phase, as outlined, will only benefit Namibia and mining complexes like the new uranium mine at Rossing. Already a transmission network has been built ready for the new power. Once peace comes to this troubled area however, the completed project will bring great benefits to all concerned.
The River Cunene rises on the high plateau region of Angola: the Bie Plateau, So also do some of the tributaries of one of Africa's greatest rivers, the Zambezi, whose waters make their first great plunge on the way to the sea at Victoria Falls. It is on the Zambezi and its tributaries that some of the greatest river development projects in Africa have taken place. Power stations have been' built at Victoria Falls and the great 600 megawatt Kariba project is world famous, with a new power station on the north bank of the dam site as well as the one on the Zimbabwe side. The Kafue Dam near Lusaka and the Shire River project in Malawi are further examples. The biggest project of all on the Zambezi is in Mozambique.
Various multi-purpose development schemes have been set up in Africa. They are essentially aimed at controlling the flow of rivers, reducing floods, and solve other problems that affect the life of the people. Such problems include floods, famine, shallowness of the water, as well as pests and diseases.
A multi-purpose scheme therefore, aims at solving the above problems. According to the modern geographical analysts, ”a large dam with a man made lake behind it can provide the answer to most if not all these problems”. That is what multi-purpose development scheme is all about whether in Africa or else where in the world.
However, as the construction of such projects takes place more practical problems are created. Such problems include: displacement of people; the occurrence of water snails which cause bilharzia; flooding also affects some villages.
The control of Africa's rivers is, arguably, of greater lasting importance than the discovery of oil or precious metals. The rivers will be there long after these have gone; and so will the benefits they bring when they are controlled. Water can provide power for industry and it can make crops grow where none grew before. Rivers can provide this water, but sometimes they do not. Often they nearly dry up and then at other times they flood uncontrollably. The water rushes uselessly out to sea, leaving dry lands without crops, industry without power and countries remain poor. Water can provide even more because fish grow in rivers and, being a source of protein, are a valuable food. In many countries people suffer from a protein deficiency because meat is too expensive. A fishing industry could supply this need; but fish cannot live in any quantity in rivers which sometimes dry up. Many countries would benefit greatly from an efficient and regular riverine transport system; but boats and barges can only sail on rivers which have no rapids and which do not dry up. Large and valuable deposits of minerals remain unexploited because there is no power supply available.
'A large dam and the man-made lake behind it can provide the answer to most, if not all, of these problems.'
That is what multi-purpose river development is all about, whether it is in Africa or elsewhere. The hydro-electricity which is produced by these dams tends to receive most publicity, but many of the other results are also of great importance. River development does not bring only benefits, but problems as well; however, generally speaking the good things tend to outweigh the new problems that may arise.
Africa has tremendous potential for river development, including H.E.P. The Aswan Dam is one of the.better known examples and will be dealt with in more detail later, together with Lake Nasser, the man-made lake which has grown up behind it.
Most of the potential lies south of the Sahara where many large rivers flow through the very narrow gorges they have cut as they plunge off the multi-stepped high plateau regions on their way to the sea. The River Zaire must have the greatest potential of them all, if you include the many huge tributaries which flow into it from north and south.
It is best that the market for hydro electricity should not be too far away from the dam site because a considerable percentage of the power generated is dissipated and lost if it has to be transmitted over long distances. However, this is not essential if a site is excellent for building a dam and for the creation of a man-made lake behind it.
It is even less important, as we shall see, if the reasons for building the dam are based on political considerations as well as economics.
First of all then, let us look briefly at one or two of the less well known examples of river control; examples which may, perhaps, receive greater recognition in a year or two's time.
The River Zaire has the greatest potential of all Africa's rivers and one of the first of its projects is to be found at Le Marinel in Shaba province where the N'Zilo Dam produces power for the copper mines from the headwaters of the River Lualaba as shown in Fig. 84. The lake, which is now nearly 100 kilometres long, provides fish for nearby towns like Kolwezi. The Inga Dam shown on page 103 now produces 1200 megawatts from the rushing waters of the Inga Falls near Matadi for the power hungry region between Kinshasa and the coast. Soon the second phase will be finished, while another dam in the Kisangani Falls region will supply Kisangani and its growing industries with a further 350 megawatts.
Further south on the Angola-Namibia border is the River Kunene where a combined H.E.P. and irrigation scheme is being built. Financed by South Africa it has, unfortunately, suffered many interruptions because of civil war in Angola and the struggle for independence in Namibia. The River Cunene (Kunene in Namibia) has tremendous hydro electric capacity and, all told, it is planned to build seventeen dams along its length which will produce 2400 megawatts. As well as the power, the irrigation potential for both countries is enormous. However, the plans so far call for three dams. One, a long way up stream at Gove is just a storage dam and was completed in 1973.
The other two dams are at Calueque and Ruacana and are virtually completed. The Calueque Dam has a dual purpose in that it will store water and control the flow to the Ruacana Dam and also pump water along a 130 kilometre irrigation canal to Oshakati in Ovamboland. Forty kilometres downstream from Calueque is the Ruacana Falls Dam where a 240 megawatt underground power station has been built, with room to add a further 80 megawatts. The power station is in Namibia and water is diverted from the Kunene along a headrace tunnel which has a 100 metre vertical drop to the generating plant, before being led into the tailrace on its way back to the Kunene.
Unfortunately the initial phase, as outlined, will only benefit Namibia and mining complexes like the new uranium mine at Rossing. Already a transmission network has been built ready for the new power. Once peace comes to this troubled area however, the completed project will bring great benefits to all concerned.
The River Cunene rises on the high plateau region of Angola: the Bie Plateau, So also do some of the tributaries of one of Africa's greatest rivers, the Zambezi, whose waters make their first great plunge on the way to the sea at Victoria Falls. It is on the Zambezi and its tributaries that some of the greatest river development projects in Africa have taken place. Power stations have been' built at Victoria Falls and the great 600 megawatt Kariba project is world famous, with a new power station on the north bank of the dam site as well as the one on the Zimbabwe side. The Kafue Dam near Lusaka and the Shire River project in Malawi are further examples. The biggest project of all on the Zambezi is in Mozambique.