Evaluating the technical, managerial, socio-economic and environmental performance of Kenya’s Ahero irrigation scheme using the analytical hierarchy process (AHP) model

Abstract

A majority of public irrigation schemes worldwide have continuously performed below their potential, and there is a need to investigate key components of irrigation scheme performance and provide study-based recommendations to enhance their optimal productivity. The Ahero Irrigation Scheme in Kenya is one such scheme, and this study is meant to evaluate the scheme’s technical, management, environmental, and socio-economic performance, which are crucial to the overall performance of an irrigation scheme. The technical factor considers the system hydraulics; management considers the maintenance of infrastructure and the organizational set-ups in the scheme to ensure effective service delivery; the environmental factor evaluates scheme operations against adverse environmental impacts; and the socioeconomic factor evaluates income by farmers from the sale of rice and credit access to enhance their farm operations. Models have been applied to evaluate the most significant parameters affecting the performance of schemes and to help plan out which factor is to be addressed first. This study aimed to evaluate the technical, managerial, socioeconomic, and environmental performance of the Ahero Irrigation Scheme in Kenya using the Analytical Hierarchy Process (AHP) model. The indicators used under the technical parameter include adequacy, equity, efficiency, and dependability. Questionnaires were used to obtain information on farmer satisfaction with irrigation water delivery amounts and timing and any extra feedback to improve the technical performance of the scheme. For the managerial parameter, the indicators include the effectiveness of infrastructure, land renovation ratio, and training. The number of functional structures was counted, and a ratio of functional to total structures was calculated to determine the effectiveness of infrastructure. The land renovation was calculated as a ratio of the area under irrigation to the total gazetted land of the irrigation scheme. Questionnaires were used to gather feedback on extension services, if any, advanced to farmers. Random sampling was used to select farmers distributed across the scheme, with a confidence level of 95%. For the environmental parameter, the indicators used include the drainage ratio, the river water ratio, and the groundwater ratio. On the technical parameter, the canal’s conveyance efficiency was found to be 60% (fair); adequacy in the upper, mid, and lower streams of the scheme was 0.99 (very good), 0.82 (good), and 0.74 (poor), respectively; equity was 0.57 (poor); the coefficient of variance for dependability for the April-July season was 5.3 (good), while for the reference year 2020, it was 16.23 (poor). The findings for the scheme’s hydraulic performance generally indicated that water distribution and utilization in the scheme were inefficient. Farmers also complained about inconsistencies in water delivery owing to the scheme’s reliance on pumping irrigation water, which is affected whenever there are power outages. On the managerial parameter, the effectiveness of infrastructure was found to be 89%, while the irrigation ratio was established at 62%. It was also noted that training farmers was not done regularly. On the socio-economic parameter, it was noted that credit was given to farmers based on their capacity to pay it back. Notable also was the fact that the income of farmers was poor, which was the result of an unavailable market for harvested rice. On the environmental parameter, the river water ratio was found to be 1, since the irrigation scheme had no other source of water other than river water. Based on the overall AHP analysis, the technical parameter (51%) should be given more priority, followed by the socio-economic parameter (32%), the management parameter (11%), and the environmental parameter (6%).