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Geography, climate and population
The Republic of Kenya is situated on the East African coast on the equator. It is bordered by Ethiopia and Sudan to the north, the Indian Ocean and Somalia to the east, the United Republic of Tanzania to the south, and Uganda and Lake Victoria to the west. The total area of the country is 580 370 km2. For administrative purposes the country is subdivided into 8 provinces and 70 districts. The altitude varies from sea level to the peak of Mt. Kenya, situated north of the capital Nairobi, which is 5 199 metres above sea level.
The soil types in the country vary from place to place due to topography, the amount of rainfall and the parent material. The soils in western parts of the country are mainly acrisols, cambisols and their mixtures, highly weathered and leached with accumulations of iron and aluminium oxides. The soils in central Kenya and the highlands are mainly the nitosols and andosols, which are young and of volcanic origin. The soils in the arid and semi-arid lands (ASAL) include the vertisols, gleysols and phaeozems and are characterized with pockets of sodicity and salinity, low fertility and vulnerability to erosion. Coastal soils are coarse textured and low in organic matter and the common types are the arenosols, luvisols and acrisols. Widespread soil salinity, which has adversely influenced irrigation development, is found in isolated pockets around the Lake Baringo basin in the Rift Valley and in the Tavetta division in the coastal provinces.
The average annual rainfall is 630 mm with a variation from less than 200 mm in northern Kenya to over 1 800 mm on the slopes of Mt. Kenya. The rainfall distribution pattern is bimodal with long rains falling from March to June and short rains from October to November for most parts of the country. The climate is influenced by the inter-tropical convergence zone and relief and ranges from permanent snow above 4 600 metres on Mt. Kenya to true desert type in the Chalbi desert in the Marsabit district in the north of the country. About 80 percent of the country is arid and semi-arid, while 17 percent is considered to be high potential agricultural land, sustaining 75 percent of the population. The forest cover is about 3 percent of the total land area.
The country has six major agro-ecological zones: Upper highland (UH), Lower highland (LH), Upper midland (UM), Lower midland (LM), Lowland (L) and Coast Lowlands (CL). These zones are associated with corresponding temperature variations ranging from freezing to 40°C. The Penman estimate of annual evaporation from open water surfaces in Kenya varies from 1 000 mm in the central highlands to 2 600 mm in the arid north.
The agricultural land covers about 33 percent of the country and is classified as:
- High potential land receiving more than 850 mm of annual rainfall and covering 67 850 km2;
- Medium potential land receiving between 730 and 850 mm and covering 31 570 km2;
- Low potential land receiving less than 610 mm and covering 42 050 km2;
- Others covering 48 670 km2.
The high and the medium potential land is considered cultivable, covering an area of 99 420 km2 or almost 10 million ha.
Total population is 32.4 million (2004), of which 59 percent lives in rural areas (Table 1). The average population density is 56 inhabitants/km2, but its distribution is highly influenced by the climate and the agro-ecological zone. The highest density of 406 per km2 is found in the Western province, followed by 350 per km2 in Nyanza, 282 per km2 in Central and only 30 per km2 in the Eastern and Coast provinces. For 2002 the population growth rate was estimated at 1.8 percent per annum. Life expectancy had increased up to 60 years by 1993 but dropped to 45 years by the year 2002 due to the high incidence of HIV/AIDS.
The overall poverty level was estimated at about 53 percent in 1997. Improved water sources are accessible for 62 percent of the population, ranging from 89 percent in urban areas to 46 percent in rural areas (Table 1). Improved sanitation facilities are used by 56 percent of the population in urban areas and by 43 percent in rural areas, while the average over the whole country is 48 percent.
Economy, agriculture and food security
Agriculture is the main sector of Kenya’s economy and its performance greatly influences the overall economical performance of the country. In 2003, the GDP was US$13.8 billion (current $) with an annual growth rate of 1 percent, and agriculture contributed 16.6 percent to the GDP. About 53 percent of the total population is economically active and approximately 74 percent of the economically active population is employed in agriculture. About 80 percent of all people working in agriculture are smallholders.
The country has a food deficit and the food supply is insecure as a result of periodic droughts and low access to production resources. In the arid and semi-arid areas, about 2 million people are permanently on famine relief and the number sometimes rises to 5 million during droughts.
Cultivated area was about 5.2 million ha in 2002, of which 4.6 million ha arable land and 0.6 million ha permanent crops. Despite the fact that 80 percent of the country is arid and semi-arid, agriculture in Kenya is dominantly rainfed with an estimated 3.12 million ha being put under food crops in 1998. The food crops are maize, wheat, sorghum, millets, cassava, Irish and sweet potatoes, bananas, fruits and vegetables. About 1.5 million hectares were under maize, which is the primary food for the majority of the population. During the same period, an estimated 500 000 hectares were under industrial crops. Production and income from export crops, such as coffee, tea, pyrethrum, horticultural crops and cotton, contribute to food security. The main agricultural imports are wheat, rice, animal and vegetable oils and sometimes maize and sugar in times of shortage. Livestock production plays a major role in food security and in the economy of the country since it sustains the livelihood of the population living in the arid and semi-arid areas.
The National Development Plan 2002-2008 recognizes Kenya as a water scarce country whereby the water demand exceeds renewable freshwater sources. It is also clear from the National Water Master Plan of 1992 that out of 164 sub-basins with perennial river flows, 90 will suffer from surface water deficit by 2010 while already 33 sub-basins without perennial river flow have an apparent water shortage.
There are five main drainage areas in the country:
- Lake Victoria, covering 8.0 percent of the country;
- Rift valley and inland lakes, covering 22.5 percent of the country;
- Athi River and coast, covering 11.5 percent of the country;
- Tana River, covering 21.7 percent of the country;
- Ewaso Ng’iro, covering 36.3 percent of the country.
The water distribution in the drainage basins is both skewed and uneven with, for example, 282 600 m3/ km2 in Lake Victoria basin and 21 300 m3/km2 in the Athi and Coast catchments.
There are six hydro-geological formations, which influence the distribution and availability of the groundwater resources: Eastern quaternary sediment areas; Bed rock areas; Western quaternary areas; Volcanic rock areas in the Rift valley; Volcanic areas outside the Rift valley; Older sedimentary areas.
The internal renewable surface water resources are estimated at 20.2 km3/year, while about 3.5 km3 of groundwater is produced annually, of which the main part (3 km³/year) is considered to overlap with the surface water resources (Table 2). It is estimated that 10 km3/year of water enters the country via transboundary rivers. The volcanic and quaternary geological formations are rich in groundwater. The annual safe abstraction yield of groundwater is estimated at 0.6 km3, out of which 0.4 km3 is the estimated yield from shallow wells while the remaining balance of 0.2 km3 is estimated to come from boreholes.
The total capacity of large and medium dams (> 15 m) is about 4.1 km3. In order to augment water supply, 1 782 small dams and 669 water pans have been constructed. There are 9 lakes with a surface area of 10 747 km2. Most of the lakes are saline with the exception of Victoria, Naivasha and Baringo. The lakes Nakuru and Naivasha have been declared Ramsar sites as wetlands of international importance for conservation of biodiversity.
There is limited seawater desalinization mainly for the hotels along the coast.
International water issues
Kenya shares a number of rivers with other countries:
- The Umba, Mara and Pangani basins are shared with the United Republic of Tanzania;
- The Sio, Malaba and Malakisi basins are shared with Uganda;
- The Omo and Daua basins are shared with Ethiopia;
- The Nile basin is shared with nine other countries.
Currently, there is no existing framework between the countries for the utilization and management of the shared water resources.
The total water withdrawal is estimated to be over 2.7 km3 (Table 3 and Figure 1). The water demand is projected to increase to 5.8 km3 by the year 2010. Agriculture is the main user of water and currently consumes about 80 percent, while municipal and commercial use accounts for the rest. There are a total of 1 800 municipal water supply schemes, out of which 700 are managed by the Ministry of Water Resource Management and Development while the communities manage the rest. There are 9 000 boreholes, most of which require rehabilitation.
As a result of the skewed water distribution between the basins and within the basins, water use conflicts among irrigation, livestock, wildlife and environmental conservation is quite common in the Ewaso Ng’iro north, in the upper catchments of the Tana basin and the Athi basins.
Irrigation and drainage
Evolution of irrigation development
The irrigation potential of Kenya has been estimated at 353 060 ha and is distributed over the basins as follows:
- 180 000 ha in the Nile (Lake Victoria) basin;
- 52 500 ha in the Kerio Valley (Rift Valley) basin;
- 111 100 ha in the East Coast basin (including the Tana and Athi basins);
- 9 460 ha in the Ewaso Ngiro (Shebelle-Juba) basin.
Irrigation development in Kenya has a long history since there are records indicating that there were irrigation systems in the 16th century along the coast and the Kerio valley (Marakwet escarpment). The system was so elaborate that a traditional water management system had evolved that maintained canals exceeding 15 kilometers, and water transfers from basin to basin along rugged terrains with technologies that puzzle the present-day engineer. The traditional water management system also allocated water between different clans and the water rotation among the different users could vary from year to year.
Other periods of irrigation development were the result of the construction of the Kenya-Uganda railway and the first and second World Wars, when irrigation schemes supplied for example vegetables to workers and soldiers. The remnants of these systems are still found in the Mt. Kenya, Tavetta, Kibwezi and Lake Victoria regions whereby the communities have developed a tradition of water management. The above-mentioned pockets of development have greatly influenced the present day pattern and distribution of irrigation development in the country.
The only deviation is the development of minor irrigation schemes through FAO and other development agencies in the arid and semi-arid lands, mainly as food security schemes in the famine stricken Kerio/Turkwel and Ewaso Ng’iro basins in the 1960s that have further influenced the pattern of development. A few centrally managed government settlement schemes have been established through the irrigation act of 1966, but they are currently experiencing a lot of institutional and management problems.
The total water managed area in 2003 was about 110 000 ha, of which 103 203 ha (94 percent) was under full control (Table 4). The remaining 6 percent are cultivated wetlands and inland valley bottoms. Of the areas under full control, 60 percent were irrigated by sprinklers and 38 percent by surface irrigation (Table 5 and Figure 2).
A comparison of the figures for 2003 in the previous table with the corresponding figures of the first half of the 1990s shows that surface irrigated areas have declined from about 44 610 ha to 39 217 ha, while areas irrigated by sprinklers have increased from about 21 000 ha to 61 986 ha.
There are three major types of irrigation schemes in Kenya (Table 6):
- Smallholder schemes;
- Commercial/Private schemes;
- Schemes of the National Irrigation Board.
Currently irrigation development is led by the private sector and by smallholder irrigation schemes with great emphasis on sustainable development. The private sector has also spearheaded irrigation development in areas close to urban centres for local vegetables and high value horticultural produce for the export market.
The reasons for considerable areas of the public schemes being non-operational are for example differing opinions between the National Irrigation Board (NIB) and the farmers about the management and running of the schemes or failure of pumping units. As can be seen from the previous table, there has been almost no expansion within the public sub-sector. The areas for each scheme type in each province are given in Table 7.
The funding of irrigation development is in transition as the emphasis has shifted from government-led development to participatory and community-driven development. As a result of the change of approach and policy, irrigation development has been categorized so that schemes in the arid and semi-arid lands (ASAL) have to be developed through grants, with the beneficiaries providing contribution in terms of unskilled labour and local materials. Community-based market-oriented irrigation schemes are currently developed through cost-sharing rather than full cost recovery on infrastructure. Full cost recovery approach has been discontinued because it has been found to be a hindrance to irrigation development especially where major infrastructure is involved. In both cases operation and maintenance are the responsibility of the community.
Some of the ongoing programmes are:
- The Central Kenya Agricultural Development Project is funded by IFAD and implemented by the Ministry of Agriculture. The project is concentrated in the dry parts of the province. The irrigation component is scaled down to kitchen gardens.
- The Eastern Province Horticulture and Traditional Food Crops Project, funded by IFAD and implemented by the Ministry of Agriculture, is promoting the production and use of traditional food crops such as cassava, millets, sorghum and sweet potatoes and also involves crop processing. The project also involves the development of irrigation schemes through cost-sharing, whereby the farmers are advanced with credit for the development of the infrastructure. The project is also promoting the marketing of horticultural crops.
- The Mini-Project, implemented by IDB and funded by JICA, is meant to build the capacity for the development of smallholder irrigation. It has three components: review of the guidelines for smallholder irrigation development, preparation of a farmers’ organization framework and human resources development.
- The Arid Land Resource Management Programme, dealing mainly with ASAL areas, is an integrated programme aimed at improving the living conditions of the people in arid and semi-arid areas. As far as irrigation is concerned, the programme has been providing irrigation equipment on grant and this has led to the rapid increase in irrigated areas in North Eastern Province in the last decade. The programme relies on the staff of the relevant government departments to implement the project.
- World Vision Kenya is focusing on the rehabilitation and development of irrigation schemes in the Turkana district to improve food security. The funding of the project is through grants.
Spate irrigation was tried in the Turkana district in the late 1980s, aimed at producing pastures for the pastoral communities. This was done through huge temporary brushwood diversion weirs with graded canals to facilitate the overtopping and even spread of the water. The systems, although productive, were not sustainable since they had been constructed through food for work programmes with little community ownership. The same principles are being applied in the Mwingi district as gully harnessing and manipulation for crop production purposes.
Rainwater harvesting is also becoming a common practice for the medium and low potential areas of the country through the construction of individual water pans and the diversion of roadside runoff, to improve food security, as is the case of the Lare division of the Nakuru district. Flood recession agriculture is widespread along the lower parts of the river Tana, where the Pokomo and the Malakote tribes exploit the seasonal flooding of the Tana for the production of bananas and other food crops.
A major limitation to this sort of development is the direct utilization of water resources without storage facilities, which has resulted in serious competition among the users especially in the Ewaso Ng’iro basin and the upper part of the Tana and Athi catchments. A point has been reached where all the easily exploitable water sources have been developed with the available technologies and future development will entail both expensive and advanced technology. An emphasis on social infrastructure and the formation of water users’ associations has been crucial in order to transfer the operation and maintenance of irrigation systems to the communities. In most irrigation schemes the communities are responsible for taking all decisions in relation to water use, crop production calendars and marketing the produce.
Role of irrigation in agricultural production, the economy and society
It has already been pointed out above that agriculture in Kenya is mainly rainfed. Only 103 203 ha of the approximately 3 million ha put under food crops are equipped for irrigation, which is about 3.5 percent. The main irrigated crops are vegetables, rice and coffee. Citrus, maize, cotton and some bananas are irrigated as well (Table 4 and Figure 3).
The cost of irrigation development varies depending on the terrain, water source, conveyance system and the length of the mainline to the irrigated area. The sum of material and construction costs ranges from US$500 to US$1 500/ha for gravity-fed surface irrigation and US$1 500 to US$4 000/ha for piped/sprinkler systems. The cost of the latter includes headworks, conveyance and on-farm infrastructure. The operation and maintenance costs are estimated at 3.5 percent of the project cost.
Status and evolution of drainage systems
The water development master plans estimate the drainage potential to be in the order of 600 000 ha, involving flood control works as well as irrigation of the drained areas. So far, 5 percent (30 000 ha) of the drainage potential has been developed. The realization of the full potential is however subject to water resource development through construction of storage facilities and major river diversion works which are beyond the capability of the farmers.
Water management, policies and legislation related to water use in agriculture
Overall responsibility for water management lies with the Ministry of Water Resources Management and Development (MWRMD), granted through the Water Act 2002. The ministry’s current policy (1999) focuses on decentralization, privatization, commercialization and stakeholder participation. The Water Act 2002 has provided the formation of a Water Resources Management Authority, responsible for water pollution, and the management of lakes, aquifers and rivers, and the establishment of a Water Services Regulatory Board, responsible for water supply through licensed water services providers.
Irrigation development in Kenya is under a number of institutions, including both the public and private sector. The National Irrigation Board (NIB), mandated with the development of the national irrigation schemes, and the Irrigation and Drainage Department (IDD), responsible for the promotion of smallholder irrigation with a wide network across the country, are under MWRMD with effect from July 2003. The River Basin Development Authorities (RBDA), with the responsibility of the planning and use of the water and land resources within their jurisdiction, are under the Ministry of Regional Development. Besides these main government institutions, there are a number of non-governmental organizations that support irrigation development.
Irrespective of the institution involved in development, the formation of water users associations (WUA) has been promoted in order to ensure sustainability of the schemes. Most of the structures and water rights for each scheme belong to the irrigating community. Water management within the smallholder irrigation schemes is the responsibility of the WUAs.
The policies and legislation for water management in agriculture are inadequate, which is exemplified by the fact that the only existing legal framework is the irrigation act of 1966 for the establishment of the NIB and management of tenant-based irrigation schemes. A national irrigation policy and legal framework are under formulation in order to comprehensively coordinate and regulate the irrigation sub-sector.
In the absence of an irrigation policy, the Ministry of Agriculture, and later Ministry of Water Resources Management and Development, has developed guidelines for the development, operation and management of smallholder farmer-managed schemes. The IDD has developed some guidelines and manuals to direct the development of smallholder irrigation and the process of community participation for sustainable development.
Water is allocated by water apportionment boards that process water permits for various users depending on the available water source. The water fees and the duration of the permit are based on the category of use. The permit for irrigation water has to be renewed after 5 years and the permit fees are based on the surface area to be irrigated. The permit holder should only use the flood flow for irrigation and will construct a reservoir to store enough water to irrigate the area specified in the permit for 90 days. These two conditions are rarely adhered to since irrigation is most required during the dry season and the cost for constructing a storage reservoir is beyond the means of most farmers.
Environment and health
Water use and its effect on the environment is being taken into due consideration as 30 percent of the flow at any point of abstraction has to be reserved for river maintenance and environment.
Salinity as result of irrigation is not widespread, except in the areas mentioned earlier where it is a result of already existing soil salinity. A case of environmental concern was experienced in the traditional irrigation area of Ngurumani, where waterlogging and swamp development was threatening the long-term sustainability of the irrigation in the area. An area of conflict exists between the wildlife and irrigation schemes, since the latter are situated in ASAL where there is also a concentration of wildlife areas.
The National Environmental Management and Coordinating Act (EMCA) No.8 of 1999 is in place to take care of the environmental impact of development and the government has established the National Environment Management Authority (NEMA) to enforce it. The act makes it mandatory to conduct an environmental impact assessment before the implementation of a project such as large-scale agriculture, use of pesticides, introduction of new animals and plants, use of fertilizers and irrigation development.
Incidences of malaria and bilharzia are common in irrigated areas.
Prospects for agricultural water management
Irrigation, drainage and water use for agriculture is hampered by the lack of a national irrigation policy and plan, which leads to haphazard irrigation development with limited coordination among the various institutions. This is further exacerbated by the evidently inequitable spatial and temporal water distribution within the country. To tackle these problems, a Draft Irrigation Policy was prepared in 2001 and a Draft Irrigation Strategic Plan covering 2003 to 2008 is under preparation.
The National Development Plan and the National Water Master Plans have emphasized the importance of water resource development if the country is to meet its future water demand, which is estimated to reach 5.8 km3 per year by 2010. This will require the construction of more storage reservoirs.
Main sources of information
Euroconsult/Delft Hydraulics Laboratory/Royal Tropical Institute. 1987. Study on options and investment priorities in irrigation development.
Hide, J.M. and Kimani, J. 2000. Informal irrigation in the peri-urban zone of Nairobi, Kenya. HR Wallingford. Wallingford, UK.
Jaetzold, R., and Schmidt, H. 1983. Farm management handbook of Kenya. Atlas of the agro-ecological zones of Kenya. Ministry of Agriculture in cooperation with German Agency of Technical Cooperation. Nairobi, Kenya.
Ministry of Agriculture/Irrigation and Drainage Branch. 1990. Atlas of irrigation and drainage in Kenya.
Ministry of Environment and Natural Resources. 2002. Country Strategy on Integrated Water Resources Management.
Ministry of Finance. 2002. The Ninth National Development Plan (2002-2008).
Ministry of Water Development. 1992. The Study on the National Water Master Plan. Prepared with the assistance of Japan International Cooperation Agency (JICA).
Ministry of Water Development. Undated. Ground water resources of Kenya (Reconnaissance study). Master planning section.
Ministry of Water Resource Management and Development. 2003. Draft Irrigation Strategic Plan 2003-2008. Irrigation and Drainage Branch.
Ministry of Water Resource Management and Development. Undated. Guidelines for the development, operation and management of smallholder farmer-managed schemes. Irrigation and Drainage Branch.
Mutunga, K., Critchley, W., Lwakuba, A. and Mburu, C.N. 2001. Farmer’s initiatives in land husbandry. Promising technologies for drier areas of East Africa. Technical Report No. 27.
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