GEOGRAPHY, POPULATION AND WATER RESOURCES
Kenya, situated on the east coast of Africa, has a total area of 580 370 km². Cultivable land is estimated at about 57 million ha, which is 98% of the total area. However, only about 10 million ha are classified as high- to medium-potential land. Approximately 80% of land is classified as semi-arid or arid. The cultivated area was 3.7 million ha in 1989, which is 38% of the high- to medium-potential cultivable land and 6.4% of the area of the country.
The total population is 27 million (1994) and is estimated to be growing at 3.4% annually on a national basis. The rural population is estimated at 80%. The leading sector in the national economy is the agricultural sector, which accounted for 30% of GDP (1988).
TABLE 1
Basic statistics and population
Area of the country | 1994 | 58 037 000 ha |
Cultivable land | 1992 | 9 936 000 ha |
Cultivated land | 1989 | 3 738 105 ha |
Total population | 1994 | 27 343 000 inhab |
Population density | 1994 | 47 inhab./km² |
Rural population | 1989 | 80 % |
Water supply coverage | ||
Urban population | 1994 | 100 % |
Rural population | 1994 | 50 % |
Climate and water resources
The mean annual rainfall of 572 mm ranges from less than 200 mm in northern Kenya to 2 000 mm/year on the slopes of Mount Kenya. The movement of the inter-tropical convergence zone (ITCZ) provides two rainy seasons: March-June and October-November. Internal surface water resources have been estimated at 20.2 km³/year from the 5 main drainage basins: Lake Victoria, Rift Valley, Athi River, Tana River and Ewaso Ngiro, and North. There are 17 major dams, with a total storage capacity of 4.06 km³ Lake storage is estimated to be 0.315 km³ and there are some 2 660 small dams and 41 subsurface dams with an estimated storage of 0.0047 km³ Water resources play an important role in hydropower development. Installed hydropower capacity is 495.3 MW (excluding Turkwell, at 106 MW) representing 20% of total capacity. Annual hydropower production is 2 449 GWh, which is 84% of the country's power generation.
The potential yield from groundwater has been estimated to be 0.6 km³/year. Some 68% of this yield is ascribed to shallow wells.
TABLE 2
Water balance
Water resources: | |||
Average precipitation | 572 | mm/yr | |
331.8 | km³/yr | ||
Internal renewable water resources total | 20.2 | km³/yr | |
Internal renewable water resources per caput | 1994 | 739 | m³/yr |
Global renewable water resources | 30.2 | km³/yr | |
Dependency ratio | 33.1 | % | |
Total dam capacity | 1992 | 4.1 | km³ |
De-salinated water | - | 10 6 m³/yr | |
Water withdrawal: | |||
- Agricultural | 1990 | 1 566.2 | 10 6 m³/yr |
- Domestic | 1990 | 403.3 | 10 6 m³/yr |
- Industrial | 1990 | 80 0 | 10 6 m³/yr |
Total | 2 049.5 | 10 6 m³/yr | |
per caput | 1990 | 87 | m³/yr |
as % of internal renewable water resources | 10.1 | % | |
Other withdrawal | 1990 | 24 | 10 6 m³/yr |
Wastewater: | |||
Produced | - | 10 6 m³/yr | |
Treated | - | 10 6 m³/yr | |
Re-used treated wastewater | - | 10 6 m³/yr |
TABLE 3
Irrigation and drainage
Irrigation potential | 1992 | 352 400 | ha |
Irrigation: | |||
1. Full or partial control Irrigation: equipped area | 1992 | 66 610 | ha |
- surface irrigation | 1992 | 44 610 | ha |
- sprinkler irrigation | 1992 | 21 000 | ha |
- micro-irrigation | 1992 | 1 000 | ha |
% of area irrigated from groundwater | 1992 | 1.0 | % |
% of area irrigated from surface water | 1992 | 99.0 | % |
% of equipped area actually irrigated | 1992 | 100 | % |
2. Spate irrigation area | - | ha | |
3. Equipped wetland and inland valley bottoms | - | ha | |
4. Other cultivated wetland and inland valley bottoms | 1992 | 6 415 | ha |
5. Flood recession cropping area | - | ha | |
Total water managed area (1 + 2 + 3 + 4 + 5) | 1992 | 73 025 | ha |
- as a % of cultivated area | 1992 | 2.0 | % |
- increase over last 10 years | - | % | |
- power irrigated area as % of water managed area | - | % | |
Full or partial control schemes: | Criteria | ||
Large schemes | > - ha | - | ha |
Medium schemes | - | ha | |
Small schemes | < - ha | - | ha |
Total number of households in irrigation | 1992 | 7 184 | |
Irrigated Crops | |||
Total irrigated grain production | - | t | |
as % of total grain production | - | % | |
Harvested crops under irrigation | 1990 | 73 025 | ha |
- vegetables | 1990 | 26 407 | ha |
- coffee | 1990 | 17 676 | ha |
- rice | 1990 | 14 088 | ha |
- citrus/fruits | 1990 | 4 910 | ha |
- other | 1990 | 9 944 | ha |
Drainage - Environment: | |||
Drained area | - | ha | |
as % of cultivated area | - | % | |
Flood-protected area | - | ha | |
Area salinized by irrigation | - | ha |
Water withdrawal for agricultural, domestic and industrial purposes was 2.05 km³ in 1990 (Figure 1), of which 1.6 km³ was for agriculture, which seems to be an overestimate. The sources for rural water supplies are shown in Figures 2 and 3.
IRRIGATION DEVELOPMENT
The National Water Master Plan (NWMP) estimates total irrigation potential to be 352 400 ha. The Total water managed area is currently 73 025 ha, of which 92% is under full or partial control (Figure 4). Only 650 ha (1 %) of the full or partial controlled area is irrigated from groundwater, leaving most of the area being irrigated from surface water, either from pumping, pick-up weirs from streams and rivers, or from storage reservoirs (Figure 5). Full or partial control irrigation techniques include about 44 610 ha under surface irrigation (basin, furrow, hose), 21 000 ha under overhead (sprinkler and centre pivot), and some 1 000 ha under drip and micro-sprinkler for the commercial cut flower export market (Figure 6). In terms of area, the major irrigated crops grown are vegetables, coffee and rice (Figure 7).
FIGURE 1: Water withdrawal (total: 2.05 km³ in 1990)
FIGURE 2: Origin of rural domestic water (1994)
FIGURE 3: Origin of rural livestock water (1994)
FIGURE 4: Distribution of the water managed area (1992)
FIGURE 5: Origin of irrigation water, full or partial control (1992)
In 1989, the Ministry of Agriculture had a target of developing 1 000 ha of smallholder schemes annually. Achievement so far has been only 200-300 ha/year, due partly to lack of technical capacity within the Ministry and partly to a change in approach by Government (structural adjustment), whereby farmers are no longer given grants and have to take out loans to cover development costs.
With under-utilization of both water resources and irrigation land potential, there is limited demand for irrigation using treated effluent. There is, however, a scheme (prison farms) on the Athi river re-using treated water from the Nairobi treatment works.
Three major types of irrigation are practiced: smallholder (28 000 ha), private commercial (26 600 ha) and government management schemes (12 000 ha) (Figure 8). Smallholder schemes grow mainly food crops and vegetables. The government-managed schemes grow mainly rice (Mwea, Ahero) with tenant plot holders on 1.6 ha plots. All inputs are undertaken by scheme management, including land preparation, and full cost recovery is obtained from the plotholders.
INSTITUTIONAL ENVIRONMENT
Various government agencies are involved in irrigation planning and implementation, the main actors being the Ministries of Agriculture (MOA), of Water Development (MOWD), and of Regional Development (MORD), and parastatals, which include the National Irrigation Board (NIB), Tana and Athi River Development Authority (TARDA), Lake Basin Development Authority (LBDA) and Kerio Valley Development Authority (KVDA). Data are available from all government agencies and parastatals, but less information is available on private schemes, which are mainly involved in coffee and tea plantations in the highlands and food and vegetable growing at lower elevations.
All abstractions of water for irrigation require a water right, as set out in the Water Act, the supreme law on water. While the framework of the laws are sound, there are problems of implementation and management of water resources and use. The NWMP has made several recommendations on improvement of implementation and management. MOA is the ministry responsible for collecting and collating all information on irrigation water use, and this information should be periodically updated and-reported to the Water Apportionment Board. On government-managed schemes, a water levy charge is made on plotholders to cover operation and maintenance. Operation and maintenance fees are paid by smallholders in gravity-fed piped sprinkler irrigation schemes and in large rice schemes.
FIGURE 6: Irrigation techniques, full or partial control (1992)
FIGURE 7: Irrigated crop areas (1990)
FIGURE 8: Irrigation management, full or partial control
TRENDS IN WATER RESOURCES MANAGEMENT
Kenya's development target is food self-sufficiency, which could be attainable through improved farming practices to increase yields and expansion of the cultivated area. It is envisaged that self-sufficiency in major food production can be achievable primarily by promotion of rainfed agriculture.
However, irrigation will continue to play an important role in the enhancement of national economic development and increases in farmers' real income. As only 19% of the potential area is equipped for irrigation, there is considerable scope for further irrigation development. Taking into account government policy and social and economic conditions in Kenya, a strategy has been drawn up. Priority projects will first be small, low-cost schemes which enhance community development, and then larger schemes having high economic efficiency.
To achieve the irrigation development target by the year 2010 under this strategy, the recommendation was to implement:
MAIN SOURCES OF INFORMATION
Euroconsult/Delft Hydraulics Laboratory/Royal Tropical Institute. 1987. Study on options and investment priorities in irrigation development.
Kimani, J.K., & Otieno, J.O. (eds) 1992. Which Way Irrigation? Proceedings of a National Irrigation Workshop.
Ministry of Agriculture, Irrigation and Drainage Branch. 1990. Atlas of Irrigation and Drainage in Kenya.
Ministry of Planning and Development, Central Bureau of Statistics. 1990. 1989 Population Census. Vol 1.
Ministry of Water Development. 1992. The Study on the National Water Master Plan. Prepared with the assistance of Japan International Cooperation Agency (JICA).
National Irrigation Board. 1993. Annual Report and Accounts 1992-1993.
Tana and Athi River Development Authority. Various Data.