Geography, climate and population
The United Republic of Tanzania consists of the mainland
and Zanzibar, which is made up of the islands Unguja and Pemba. Its
total area is 945 090 km2. The country is bordered in the
north by Kenya and Uganda, in the east by the Indian Ocean, in the south
by Mozambique and in the west by Rwanda, Burundi, the Democratic
Republic of the Congo and Zambia. The Indian Ocean coast is some 1 300
km long, while in the northwest there are 1 420 km of shoreline on Lake
Victoria, in the centre-west there are 650 km of shoreline on Lake
Tanganyika and, in the southwest, 305 km of shoreline on Lake Malawi.
The terrain comprises plains along the coast, a plateau
in the central area, and highlands in the north and south. The northeast
border with Kenya is dominated by Mt. Meru and Mt. Kilimanjaro.
Southwards is the Central Plateau reaching elevations above 2000 m. The
mountain range of the Southern Highlands separates the Eastern plateau
from the rest of the country.
Land cover is dominated by woodland, grassland and
bushland which account for about 80 percent of the total land area.
Cultivable area is estimated to be 40 million ha, or 42 percent of the
total land area. In 2002, 13 percent of the cultivable area was actually
cultivated, comprising 4 million ha of arable land and 1.1 million ha
under permanent crops (Table 1).
The climate varies from tropical along the coast to
temperate in the highlands. There are two types of seasonal rainfall
distribution:
- The unimodal type, where rainfall is usually from October/November to April, found in the central, southern and southwestern highlands;
- The bimodal type, comprising two seasons: the short rains (Vuli) fall from October to December, while the long rains (Masika) fall from March to June. This type occurs in the coastal belt, the northeastern highlands and the Lake Victoria Basin.
Annual rainfall varies from 500 mm to 1 000 mm over most
of the country. The highest rainfall of 1 000 mm to 3 000 mm occurs in
the northeast of the Lake Tanganyika basin and in the Southern
Highlands. Mean annual rainfall is 1 071 mm. Zanzibar and the coastal
areas are hot and humid and average daily temperatures are around 30 °C.
October-March is the hottest period. Sea breezes however temper the
region’s climate and June-September is coolest with temperatures falling
to 25 °C. In the Kilimanjaro area, temperatures vary from 15 °C in
May-August to 22 °C in December-March.
The total population is 37.7 million (2004), of which 63 percent is rural (Table 1). The population density is 40 inhabitants/km2.
The vast majority of the population lives inland, far away from the
coastline. Poverty is concentrated in the rural areas; however, urban
poverty has accompanied rapid urbanization. The national poverty rate is
about 36 percent. In 2002, 92 percent of the urban and 62 percent of
the rural population were using improved drinking water sources (Table 1).
Economy, agriculture and food security
The country’s GDP was US$9.9 billion in 2003, and the
value added in agriculture was 43.4 percent of GDP. The agricultural
sector continues to lead economic growth, in spite of the recent
emergence of the new high-growth sectors of mining and tourism, and it
continues to have the highest impact on the levels of overall economic
growth. Agriculture provides work for 14.7 million people, or 79 percent
of the total economically active population, and 54 percent of
agricultural workers are female. Small-scale subsistence farmers
comprise more than 90 percent of the farming population, with medium-
and large-scale farmers accounting for the rest.
The main food crops grown are maize, sorghum, millet,
paddy, wheat, sweet potato, cassava, pulses and bananas. Maize is the
dominant crop with a planted area of over 1.5 million ha during recent
years, followed by paddy with more than 0.5 million ha over recent
years. The main agricultural products exported by the United Republic of
Tanzania are green coffee, cashew nuts and tobacco that, in 2001,
represented about 41 percent of all agricultural exports. The main
agricultural products imported are wheat and palm oil.
In recent years, the country has not been
self-sufficient in cereals, but it is self-sufficient in non-cereals at
the national level. However, there is a clear difference in the supply
capabilities of staple-food crops among the regions:
- In Arusha, Coast, Dar es Salaam, Dodoma, Kigoma, Kilimanjaro, Mara, Tabora and Tanga, the supply is constantly less than demand;
- Iringa, Mbeya, Mwanza, Rukwa, Ruvuma and Shinyanga have attained self-sufficiency or produce surpluses.
Rainfed cropping systems can be classified into three broad categories:
- Short rains (Vuli) season from September/October to January/February;
- Long rains (Masika) season from February/March to June/July;
- A combination of the two (Musumi) from November to June.
Water resources and use
Water resources
Tanzania has nine major drainage basins that, according to the recipient water body, can be categorized as follows:
Draining to the Mediterranean Sea:
- The Lake Victoria basin, which is part of the Nile River basin.
Draining to the Indian Ocean:
- The Pangani River basin;
- The Ruvu/Wami River basin;
- The Rufiji River basin;
- The Ruvuma River and Southern Coast basin;
- The Lake Nyasa (Lake Malawi) basin, which is part of the Zambezi River basin;
Draining to the Atlantic Ocean:
- The Lake Tanganyika basin, which is part of the Congo River basin.
Rift Valley (endorheic) basins, of which amongst others:
- The Lake Eyasi and Bubu depression; Lake Manyara;
- The Lake Rukwa basin.
River regimes follow the general rainfall pattern. River
discharge and lake levels start rising in November-December and
generally reach their maximum in March-April with a recession period
from May to October/November. Many of the larger rivers have flood
plains, which extend far inland with grassy marshes, flooded forests and
ox-bow lakes.
Total renewable water resources amount to 93 km3/yr (Table 2), of which 84 km3/yr are internally produced and 9 km3/yr
are accounted for by the Ruvuma River, which flows on the border
between Tanzania and Mozambique. Renewable groundwater resources are
estimated at 30 km3/yr, of which all but 4 km3/yr are considered to be overlap between surface water and groundwater.
About 5.7 percent of the total land area of the United
Republic of Tanzania is covered by three lakes, which also form the
border to neighboring countries:
- Lake Victoria, which is part of the Nile River basin, is shared with Kenya and Uganda. Its total area is 68 800 km2, of which 51 percent belong to the United Republic of Tanzania.
- Lake Tanganyika, which is part of the Congo River basin, is shared with Burundi, Democratic Republic of Congo and Zambia. Its total area is 32 900 km2, of which 41 percent belong to the United Republic of Tanzania.
- Lake Nyasa or Lake Malawi, which is part of the Zambezi River basin, is shared with Malawi and Mozambique. Its total area is 30 800 km2, of which the United Republic of Tanzania claims 5 569 km2 or 18 percent.
Other lakes include Lake Rukwa, Lake Eyasi, Lake
Manyara, Lake Natron, Lake Balangida. The main dams in the United
Republic of Tanzania are given in Table 3.
In the 1970s, 21 small-scale earthfill-type dams were
constructed mainly on seasonal rivers in the Tabora region for
irrigation and municipal supply purposes. All except seven of them
suffer from serious sedimentation. In addition to these dams, there are
many smaller dams over the whole land, called Charco dams, for
irrigation, municipal and livestock purposes. In general, dam
construction is largely restricted by hydrological and topographic
conditions.
Water use
Total water withdrawal in mainland Tanzania was estimated for the year 2002 to be 5 142 million m3 (Table 4). Agriculture consumes the largest share with 4 624 million m3 (almost 90 percent of total) of which 4 417 million m3 for irrigation and 207 million m3 for livestock, while the municipal sector uses 493 million m3. Total water withdrawal by the municipal sector and irrigation in Zanzibar is estimated to be about 42 million m3. Of this, withdrawal on Unguja Island is 33 million m3 and on Pemba Island it is 9 million m3. Industry in Tanzania consumes an estimated 25 million m3 (Figure 1).
International water issues
The United Republic of Tanzania shares three major lakes
(Lake Victoria, Lake Tanganyika and Lake Nyasa (Malawi)) with
neighbouring countries, as well as Ruvuma River on the border with
Mozambique.
Since Lake Victoria is part of the Nile River basin, the
United Republic of Tanzania is one of the member countries of the Nile
Basin Initiative, which was officially launched in February 1999 in Dar
es Salaam, following an agreement of the Ministers of Water Affairs of
the Nile Basin States.
The Kagera River basin covers the upper part of the Nile
Basin until its entry into Lake Victoria and involves Burundi, Rwanda,
the United Republic of Tanzania and Uganda. The Kagera Basin
Organization (KBO) (defunct in 2004) was set up as the organization for
the management and development of the Kagera River basin. The objective
of the KBO was to deal with all questions concerning the activities to
be carried out in the Kagera River basin. In addition, an agreement to
manage Lake Victoria has been signed by the countries of the East
African Community and programmes to implement the agreement are being
studied.
At the bilateral level, the United Republic of Tanzania
is implementing a project on the stabilization of the Songwe River
course jointly with Malawi, through the Malawi/Tanzania Joint Permanent
Commission of Cooperation (JPCC).
The United Republic of Tanzania, together with Angola,
Burundi, Cameroon, the Central African Republic, the Congo, the
Democratic Republic of the Congo, Rwanda, and Zambia, shares the Congo
(Zaïre) River; and in the Zambezi River Basin with Angola, Botswana,
Malawi, Mozambique, Namibia, Zambia, and Zimbabwe. The Zambezi
Watercourse Commission (ZAMCOM) was created in 2004 between the eight
countries sharing the basin.
Irrigation and drainage development
Evolution of irrigation development
Irrigation potential is estimated by the 2002 Study on
the National Irrigation Master Plan (NIMP) to be 2 123 700 ha in
mainland Tanzania, while for Zanzibar it is estimated to be 8 521 ha.
The criteria for this estimate are water resources potential, land
resources potential and socio-economic potential. The high potential
areas are located in roughly four locations:
- Mara, Mwanza and Kagera regions;
- Arusha and Kilimanjaro regions;
- Morogoro region;
- Mbeya and Iringa regions.
Irrigation in the form of traditional irrigation schemes
goes back hundreds of years in the country. Those schemes have however
become inadequate as a result of an increase in population, wear and
tear, catchment degradation etc. The response to the increasing
shortcomings of these schemes from colonial times until recently has
largely been:
- the construction of new irrigation estates for parastatal organizations;
- the construction of new modern style schemes to be run by smallholders;
- the rehabilitation or upgrading of traditional irrigation schemes.
However, the great majority of those schemes have had
very limited success and the only successful ones are in the private
sector. In general, the development of irrigated agriculture in the
United Republic of Tanzania has been slow, for reasons such as:
- the absence of vital irrigation data for planning purposes;
- a lack of resources on the part of the government (funds and trained irrigation personnel);
- the absence of national irrigation investment criteria;
- the lack of any national coordination of irrigation development, despite available funding from donors.
According to the NIMP, the total area equipped for
irrigation is 184 330, of which 183 988 ha in mainland Tanzania and 342
ha in Zanzibar (Table 4).
The NIMP had inventoried 1 428 irrigation schemes (including water
harvesting schemes) in mainland Tanzania, of which 29 were being
implemented, 79 did not need rehabilitation and 37 had been
rehabilitated within the last five years. The rest, about 90 percent of
all schemes, needed some form of rehabilitation. In Zanzibar, 19
irrigation schemes were inventoried. Rainwater harvesting schemes cover
7 934 ha in mainland Tanzania, mainly located in the regions of Dodoma,
Mara, Mwanza, Shinyanga, Singida and Tabora. In these schemes, runoff is
diverted from residential areas, paths and transient streams to fields
in the bottom of the valleys, where mainly paddy rice is grown. The most
important system is the diversion of ephemeral streams for distances up
to 2 km.
Most of the irrigated areas are under surface
irrigation, mainly used by smallholders. Water distribution is usually
by lined and unlined canals, and furrows and basins are widely used.
Sprinkler irrigation is used by few large-scale commercial farmers. It
is not common amongst smallholders. Drip irrigation is rarely used.
Almost all irrigation water on the mainland is surface water, and
groundwater is utilized on only 0.2 percent of all irrigated areas (Figure 2).
The following types of irrigation schemes are distinguished in the United Republic of Tanzania (Figure 3):
- Modern irrigation schemes (35 847 ha): these are formally planned and designed schemes with full irrigation facilities and usually a strong element of management by the government or other external agencies. Those schemes are developed in the regions of Kilimanjaro, Morogoro and Mbeya. All parastatal managed irrigation schemes also fall under this category.
- Traditional irrigation schemes (122 630 ha): these have been initiated and operated by the farmers themselves, with no intervention from external agencies. They include schemes based on traditional furrow irrigation for the production of fruit and vegetables in the highlands and simple water diversion schemes on the lowland for paddies.
- Improved traditional irrigation schemes (25 511 ha): these are traditional irrigation schemes on which, at some stage, there was intervention by an external agency, such as the construction of a new diversion structure.
- Water harvesting schemes: water harvesting and flood recession schemes, on which sub-subsistence farmers have introduced simple techniques to artificially control the availability of water to the crops.
Of the 1 428 irrigation schemes inventoried by the NIMP,
1 328 were smallholder schemes, 85 private schemes and 15
government-managed schemes. About 3 percent of the total area is covered
by small schemes with an area of less than 50 ha each, while 58 percent
is covered by schemes of over 500 ha each (Table 5 and Figure 4).
Gravity-fed irrigation schemes account for over 99
percent of the irrigated area, while the rest uses pumps for water
abstraction (Table 6 and Figure 5). The latter schemes are mainly located in the regions of Kagera, Mara and Mwanza.
Role of irrigation in agricultural production, the economy and society
The main irrigated crops are paddy rice and maize,
accounting for about 48 percent and 31 percent of the irrigated areas in
2002 (Table 4 and Figure 6).
Other irrigated crops account for 44 percent of the irrigated areas and
comprise beans, vegetables (including onion, tomato and leaf
vegetables), bananas and cotton. From the above figures, the cropping
intensity is 123 percent. Private irrigation schemes produce cash crops
such as tea, coffee, cashew and sugar cane. In the National Irrigation
Development Plan of 1994 (NIDP), the yields of rainfed and irrigated
rice were compared and are shown in the Table 7.
The cost for the rehabilitation, improvement and
construction of irrigation schemes was estimated by the NIMP (2002), as
given in Table 8,
where the lower values reflect the cost of rehabilitating irrigation
canal only, while the higher costs refer to the construction or
replacement of both diversion weir and irrigation canal. For the
implementation of the NIMP, the operation and maintenance cost was
assumed to be US$15/ha per year.
Water management, policies and legislation related to water use in agriculture
Institutions
The main institutions involved in agricultural water management are:
- The Irrigation Section (IS) within the Ministry of Agriculture and Food Security (MAFS) which is responsible for irrigation development.
- The Water Division within the Ministry of Water and Livestock Development (MWLD) which is responsible for the design, construction, equipment, maintenance and operation of laboratories, water planning, water supply, water research, sewerage and sanitation.
- The Central Water Board (CWB) within the MWLD which is the principal advisory body to the government on matters pertaining to the utilization of water nationally and to the allocation of water rights. It is given executive power over pollution control.
- The National Environmental Management Council (NEMC) within the Ministry of Tourism, Natural Resources and Environment (MTNRE) which is the advisory body to the Government on environmental matters.
- The Regional Secretariat which is a local agency of central government with the function to encourage local governments to execute and implement policies. Its staff has been significantly reduced, and part of the personnel transferred to local governments because of the Local Government Reform Programme (LGRP), which is a major decentralization effort. In the Regional Secretariat, the agricultural officer is responsible for irrigation development.
- Local Government Authorities (LGA) which are given greater autonomy. Some executive functions are transferred to them from central government, under the abovementioned LGRP. These reforms will be critical to the delivery of support services to smallholders and rural infrastructure development. In the District Council, the District Agriculture and Livestock Development Officer (DALDO) is in charge of irrigation development. However, not all DALD Offices have irrigation officers and many are seriously understaffed.
Water management
The responsibility for managing the water resources of
the country lies with the MWLD. Water resources management involves
water resources development, water allocation, pollution control and
environmental protection. Until the 1990s, water was managed by the MWLD
on the basis of administrative regions. Since then, the emphasis has
changed to managing water resources on the basis of river basins. To
strengthen river basin management, the MWLD was implementing the river
basin management component of the River Basin Management and Smallholder
Irrigation Improvement Project (RBMSIIP) in the Rufiji and Pangani
basins. The project, the implementation of which began in December 1996,
was intended to deal effectively with water management problems and
improve the efficiency of smallholder irrigation.
Irrigators’ Associations (IAs), or Irrigators’ Groups
(IGs), have been formed from the early 1990s onwards, for example in the
Pangani basin. They are expected to become a main actor in the
irrigation sector, representing part of the private sector. The rights
and obligations of these groups cannot always be clearly and uniformly
defined under the present legal framework. A new legal framework for the
IGs seems to be very important and necessary.
Finances
The average share of irrigation development for the five
years 1998/99-2002/3 was 1.46 percent of the Government’s Development
Expenditure.
Policies and legislation
The regulatory and institutional framework for water
resources management is provided for under the Water Utilization
(Control and Regulation) Act. No.42 of 1974 as amended by the Water Laws
(Control and Regulation) Act of 1997 and the Water Laws (Miscellaneous
amendments) Act of 1999. They stipulate that all water in mainland
Tanzania is vested in the United Republic of Tanzania and the Minister
responsible for water development is empowered to regulate the use of
water from any source in any area of the country on a national basis, to
declare such a source to be a national water supply for the purpose of
the Act. The Law sets conditions on the use of water and appoints the
Principal Water Officer, under the direction of the CWB, to be
responsible for setting policy and allocation of water rights at the
national level. The Water Act is currently under review. The new Act is
expected to establish a mechanism for a more participatory management of
water resources. With irrigation an important economic activity in most
if not all of the river basins of the United Republic of Tanzania, a
more balanced approach will probably be adopted.
In 1994, the National Irrigation Development Plan (NIDP)
was prepared including the objectives of "Removal of Sectoral
Constraints" and "Implementation of Irrigation Infrastructure". Progress
so far has only been about 30 percent for the components related to
both the objectives mentioned above, while completion is envisaged by
2014. The main reasons for the slow progress are inadequate
institutional reforms and lack of human and financial resources.
Existing land tenure arrangements do not attract
long-term commitments of resources for improving the productivity of
land through irrigation or drainage. The 1999 Land Act has laid the
foundation for a more transparent execution of land-based transactions
and property rights. However, problems in the administrative procedures
and in the use of land as collateral for obtaining credit still need to
be addressed.
The Agricultural Sector Development Strategy (ASDS),
finalized in 2001, focuses on the period 2002-2007 and proposes to apply
the principles of integrated soil and water management, emphasizing the
use of low-cost approaches by smallholders and to promote and support
small-scale irrigation.
In July 2002, the Government issued the National Water
Policy whose main goals are to establish a comprehensive framework for
sustainable development and management of water resources and for
participatory agreements on the allocation of water use. The Government
will not be in charge of executive functions, i.e. the actual delivery
of the services, which are the responsibility of the LGAs. Central
statements of the Policy are that "water will be subject to social,
economic and environmental criteria" and that "every water use permit
shall be issued for a specific duration". This could mean that
irrigation might have to compete with industrial sectors and that a
continuous irrigation water supply might not be guaranteed.
Environment and health
The National Environment Policy of 1997 identified the following major environmental problems:
- Lack of accessible, good quality water for both urban and rural inhabitants;
- Deterioration of aquatic systems;
- Pollution and poor management threatening the productivity of lake, river, coastal and marine waters.
The reasons identified for the above problems are
inadequate water management, inadequate monitoring and inadequate
involvement of stakeholders. Alleviation of the problems will be
achieved through:
- Control of the agricultural runoffs of agrochemicals to minimize the pollution of surface and groundwater;
- Improvement of water-use efficiency in irrigation, including controls on water logging and salinization.
The sectoral policy for water and sanitation of the National Environment Policy of 1997 includes:
- Planning and implementation of water resources and other development programs in an integrated manner and in ways that protect catchment areas and their vegetation cover;
- Improved management and conservation of wetlands;
- Promotion of technology for efficient and safe water use, particularly for water and wastewater treatment, and recycling;
- Institution of user charges that reflect the full value of water resources.
Existing data on the incidence of water-borne,
water-related and water-washed diseases indicate that these are mostly
prevalent where people use contaminated water or have little water
available for daily use. Such diseases account for over half of the
diseases affecting the population.
Prospects for agricultural water management
The NIMP (2002) proposed an irrigation development
programme that includes only smallholder schemes and is to be
implemented by 2017. The whole programme plans to develop a total of
405 421 ha (Table 9).
A major challenge in order to improve the irrigation
sector is to overcome the following problems in irrigation schemes, as
identified by the NIMP (2002):
- Lack of appropriate participatory approaches;
- Unsound logical structure of projects and weak linkage between purpose and output of projects;
- Misunderstanding of the concept of "simple and low-cost technology", taken to mean "easy and no concern of technical know-how and understanding";
- Lack of feedback system on the lessons learnt through actual experience in implementation of irrigation projects;
- Inadequate guidelines and manuals in planning, design and construction supervision, and lack of proper application of them;
- Need for an effective support system for the WUAs’ (IGs’) activities;
- Lack of human resources and active participation of local government authorities in irrigation development.
The public sector will gradually but increasingly limit
its role to financing the provision of collective goods and services,
including land and water resource utilization and management. Mechanisms
will be developed for private and public sector collaboration in the
delivery of effective support services.
Floodplains, mainly used for agriculture and notably
rice cultivation, have a conspicuous future in the extensive Maasai and
Wembere Steppe, Usangu Plains and the Rukwa and middle Malagarasi River
basins. They are the most promising areas for the introduction of the
pedal pump for lifting up water for irrigation and fish farming.
Experience has shown that the use of pedal pumps allows the farmers to
irrigate vegetable gardens, the benefits of which are twofold: i) as an
off-farm income generating activity; ii) vegetables could bring
additional nutritional value to the village community.
The unexploited natural resource base of 40 million ha
of cultivable land of the United Republic of Tanzania, abundant sources
of water and several agro-ecological zones, permits virtually unlimited
expansion and diversification in crop production, and in particular the
development of irrigated agriculture. Such development, especially for
rice and cash crop production, could contribute significantly to
stabilizing agricultural production and increasing income and is,
according to the above, not likely to be constrained by the supply of
natural resources in the country. However, access to these natural
resources may be a binding constraint in some cases.
Main sources of information
FAO. 2001. Support to SPFS Extension Phase I: Vegetable Gardens irrigating from shallow wells using pedal pump technology. GCP/URT/118/SWI. Project Document.
FAO. 2004. Country Brief Tanzania. Policy Assistance Division, Technical Cooperation Department.
Geheb, K., and Sarah, M.T. (eds.). 2002. Africa’s inland fisheries: the management challenge. Fountain Publishers. Kampala.
International Centre for Hydropower (ICH). 2003. Hydropower Development in Tanzania. Fact Sheet.
International Commission for Irrigation and Drainage (ICID). Undated. Country Profile Tanzania.
Kitova, H.H. 2001. Presentation Paper on the Development and Management of Hydropower Resources in Tanzania.
Ministry of Agriculture and Food Security (MAFS) and Japan International Cooperation Agency (JICA). 2002. The Study on the National Irrigation Master Plan in the United Republic of Tanzania. Prepared by Nippon Koei CO. Ltd. and Nippon Giken Inc.
Ministry of Agriculture and Food Security (MAFS) and Japan International Cooperation Agency (JICA). 2002. Zanzibar Irrigation Master Plan. Prepared by Nippon Koei CO. Ltd. and Nippon Giken Inc.
Ministry of Agriculture and Food Security (MAFS). 2004. Irrigation
development in Tanzania: Current performance, institutional support,
agronomy, community participation, environmental, infrastructure, water
and land related policies. Draft report by Working Group 2 Task Force 1, Agricultural sector development programme.
Morse, K. 1996. A Review of Soil and Water Management Research in Semi-Arid Areas of Southern and Eastern Africa. Natural Resources Institute, Chatham, UK.
United Republic of Tanzania. 1994. National Irrigation Development Plan (NIDP). Agriculture and Irrigation Department.
United Republic of Tanzania. 1997. National Environmental Policy. Vice President’s Office, Dar es Salaam.
United Republic of Tanzania. 2001. Agricultural Sector Development Strategy.
United Republic of Tanzania. 2002. National Water Policy.
World Bank. 2002. Tanzania at the Turn of the Century. Background Papers and Statistics. Washington D.C., U.S.A.
Hakuna maoni:
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