Evaluating the Technical, Managerial, Socio-economic and Environmental Performance of Kenya’s Ahero Irrigation Scheme Using the Analytical Hierarchy Process (AHP) Model

Abstract

The technical, management, environmental and socio-economic factors are crucial in the performance of an irrigation scheme. If a scheme is performing poorly in either of these factors, the overall operational efficiency of the scheme will be affected. The aim of this study was to evaluate the technical, managerial, socio-economic and environmental performance of Ahero Irrigation Scheme in Kenya using the Analytical Hierarchy Process (AHP) model. The indicators used under the managerial parameter include: effectiveness of infrastructure, land renovation ratio and training. The total number of structures in the scheme were determined. The number of functional structures were counted and a ratio of functional to total number of structures calculated to determine the effectiveness of infrastructure. Land renovation was calculated as a ratio of area under irrigation to the total gazette 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 and at a confidence level of 95%. For the technical parameter, the indicators used 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 environmental parameter, the indicators used include: Drainage ratio, the river water ratio and the Groundwater ratio. On the managerial parameter, EoI was found as 89% while the irrigation ratio was established as 62%. It was also noted that training to farmers was not done regularly. On the technical parameter, the canal’s conveyance efficiency was found as 59.98% (poor); 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 was 16.23 (poor). The findings for the scheme’s hydraulic performance generally indicated that water distribution and utilization in the scheme was inefficient. Farmers also complained on inconsistencies in water delivery owing to the scheme’s reliance on pumping irrigation water, which is affected whenever there are power outages. Preference was to have the irrigation water flow by gravity from the river to the very outlet of the scheme. On the socio-economic parameter, it was noted that credit was given to farmers based on their capacity to pay back. Notable also was that the income by farmers was poor, and was the result of unavailable market for the harvested rice. On the environmental parameter, the river water ratio was found as 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 (32%), management (11%) and the environmental parameters (6%) respectively.