Mwea Irrigation Settlement Scheme (MIS) is located in Kirinyaga County and falls within two sub counties i.e. Mwea East and Mwea West sub counties. Development of the scheme started in 1954 from the Tebere section with about 65 acres in irrigation farming and has since grown to the current gazetted area of 30,050 acres. Out of these, 22,000 acres have been developed for paddy rice production while the remaining area is utilized for settlement, public utilities and growing of subsistence crops. Since then, expansion has been done to the freehold area (referred to as out-growers) surrounding the scheme by a total of 8,600 acres; hence the total area under paddy rice production in MIS is 28,600 acres of irrigation farming.
The National Irrigation Authority (NIA) has improved, rehabilitated and developed irrigation infrastructure for the farmers to engage in production activities. The scheme lies along the drainage basins of Rivers Nyamindi and Thiba which supply the irrigation water. There is still potential of up to 10,000 acres for expansion within the surrounding areas. However, this is constrained by lack of sufficient water for irrigation. The scheme area is largely plane and predominantly covered with black cotton soils, with a few raised spots of red soil. Rice paddies have been developed on the low areas that are covered with black cotton soils while the high spots covered with red soils have been reserved for settlement and production of upland crops.
The current approach to scheme management is Participatory Irrigation Management (PIM), where the government through National Irrigation Authority and the farmers through their organizations (Irrigation Water User Association [IWUA], Mwea Rice Growers Multipurpose [MRGM] and Lainisha Sacco) have partnered in management of the irrigation scheme. Each of the four i.e. the Authority, IWUA, MRGM and Lainisha, have clearly defined roles in PIM. The Irrigation Authority’s key responsibility in scheme management is operation and maintenance of the primary and secondary infrastructure; while the farmers are responsible for the tertiary infrastructure. Other roles include land administration, capacity building, irrigation expansion and rehabilitation of the irrigation infrastructure.
The scheme’s irrigation combined water intake capacity is at 18.14m3/s (Thiba 11.12m3/s and Nyamindi 7.02m3/s). There are three rice production systems being practiced in the scheme currently i.e. conventional rice production system (farmers’ transplant 21 – 28 days old seedling, randomly at a spacing of about 10cm and the paddy field is continuously flooded until maturity), system of rice intensification (SRI) and water saving rice culture (WSRC). In both SRI and WSRC farmers practice intermitted irrigation (alternate wetting and drying (AWD)), use of younger seedlings (10 – 15 days old) and wider spacing of between 20 to 25 cm. SRI and WSRC are being promoted in the scheme since they save on irrigation water (up to 30%), reduce on greenhouse gas emission, save the farmer on farm in-puts and increase land productivity.
Currently the scheme practices two and half production seasons in a year. The main season starting in July and ending in December, giving way to a ratoon crop that starts in December and is harvested in February. The second season whose acreage varies from 5,000 to 10,000 acres depending on the prevailing weather conditions begins in March and ends in July. The total annual rice production in the scheme is estimated at 113,000 metric tons. This represents a 44% increase in production compared to previous years. The rise in production is attributed to enhanced mechanization, increased cropping intensity and increased area under production due to enhanced on-farm irrigation water management.
Projected Benefits/ Benefits being realized
- Saving on foreign exchange;
- Increased health benefits mainly through improved sanitation due to better access to water;
- Positive impact on poverty reduction as a result of increased productivity and increased employment opportunities;
- Flooding control;
- Improved benefits accruing from water use for rural domestic and livestock purposes and
- Increased groundwater recharge and subsequently reduction in opportunity costs of water uses.
Mwea Irrigation Scheme Layout Map
A farmer at Mwea Irrigation Scheme
- Location/County – Mwea West and East Sub Counties of Kirinyaga County, approximately 100km North East of Nairobi City
- Year of establishment – 1954
- Gazetted Area – 30,350 Acres
- Main Crop – Basmati Rice
- Area under Irrigation –30, 600 (20, 000 acres in the main scheme & 10, 600 acres Expansion area)
- Source of irrigation water – River Nyamindi and River Thiba.
- No. of farmers –18,070
- Type of irrigation –Conveyance System: – Partially lined open channels Distribution System: – Earthen Canals Application System: – Basin/flood Irrigation system
- Other Crops – Tomatoes, onions, French Beans, Maize and other horticultural crop