Assessment of irrigation systems’ performance and sustainability in Burundi

Dissertation

Irrigated agriculture has a crucial role to play in enhancing food security; hence, irrigation expansion would significantly increase agricultural production, improving household income and reduce food insecurity and poverty levels among smallholder farmers. However, majority of irrigation schemes developed in Burundi have performed below their potential. Evaluation of the performance of an irrigation schemes is essential in knowing whether water availability meets or exceeds demand. In Burundi, these evaluations are limited. This study aimed to assess the irrigation systems’ performance and sustainability in Burundi with a case study of Kidwebezi Irrigation Scheme. Specifically, this study intended (i) to evaluate the performance of the irrigation structures, (ii) to assess the water delivery performance using technical indicators and (iii) framers’ knowledge and to assess the effect of Irrigators’ Association on the performance of Kidwebezi Irrigation scheme with the target of evaluating the existing operation rules and proposing alternative options for further improvement. In this study, a float method was used for determining the flow rate. The CROPWAT Penman-Monteith method was used to determine the reference crop evapotranspiration, the combination of Food and Agriculture Organization (FAO) CROPWAT 8.0 simulation software and the CLIMWAT 2.0 tool was used to calculate the crop water requirement (CWR) of the paddy. Field observations (state of a structure) and physical work were used to evaluate the performance of the irrigation structures. Based on the technical performance indicators such as efficiency, adequacy, dependability, equity and water productivity, the performance of water delivery was assessed. A social economic survey (farmer interviews, focus group discussions and key informants) was undertaken to assess financial self-sufficiency, fee collection and relative water costs of the scheme. Results for the performance evaluation of irrigation structures showed that 84.15%were still functioning. On the physical condition part, the findings showed that the intake was working at 80%; canals network was operational at 80% while command area development was functioning at 88%. For the conveyance efficiency, the results indicate that 82.48%, 80.40% and 66.38% of water conveyed reached the destined farm for lined main canal, lined secondary canal and unlined secondary canal, respectively. The total net irrigation and total gross irrigation were 342.2 mm and 760.4 mm. The study results showed that the irrigation system was good in terms of adequacy and poor in terms of efficiency while it was fair to both dependability and equity. Moreover, the results for the assessment of effect of Irrigators’ Association with regard to financial viability and sustainability of the scheme were found to be encouraging. The results showed that the effectiveness of fee collection (EFC) was 87.77%, the financial self-sufficiency (FSS) was 3.11 with an average relative water cost of 0.05 and 97.75% of the scheme were still irrigated. The results from farmer interviews, focus group discussions and key informant showed that the uncontrolled paddy farming expansion, lack of updated irrigation knowledge and technologies and low efficiency on water use are the main causes of low yields of paddy in the Kidwebezi Irrigation Scheme.

IRRI-Burundi