Abstract : The Yaabra irrigation scheme, with a gross area of 600 ha, is located in the Autonomous District of Yamoussoukro, Côte d'Ivoire, and forms part of the Agro-Industrial Pole Project for the Bélier Region (2PAI-Bélier). Designed for rice and vegetable production, the scheme is affected by the deterioration of its hydraulic infrastructure and the impacts of climate variability, compromising water management and agricultural productivity. This thesis presents a diagnostic assessment and a detailed engineering design (Detailed Preliminary Design - DPD) aimed at proposing a sustainable rehabilitation solution for the irrigation scheme. The methodology adopted was based on the collection and analysis of topographic, hydrological, pedological, climatic and socio-economic data, complemented by field investigations and hydraulic studies to assess available water resources, estimate crop water requirements, and design the irrigation, drainage and pumping infrastructures. The results show that, following the optimization of the layout, the net irrigable area is 497 ha, including 243 ha for rice cultivation and 254 ha for vegetable crops. The proposed irrigation system is an open-channel gravity-fed network supplied by the Bandama Blanc River and the Yaabra Dam, consisting of one primary canal divided into two reaches, 22 secondary canals, and 57 tertiary canals. The selected irrigation design discharge is 3.3 L/s/ha, while the internal drainage network was designed for a drainage coefficient of 3.57 L/s/ha. Water supply is ensured by a pumping station with an installed capacity of 1,470 L/s and a total dynamic head of 15 m. The study also included an Environmental and Social Impact Assessment (ESIA), leading to the development of an Environmental and Social Management Plan (ESMP) to ensure the sustainable implementation of the project. The estimated rehabilitation cost amounts to CFAF 9,627,186,898 (excluding VAT), corresponding to an average cost of CFAF 16,045,311 per hectare (excluding VAT). The implementation of the project will improve water management, increase agricultural productivity, and strengthen the resilience of the irrigation scheme to climate variability.

Abstract : The Yaabra irrigation scheme, with a gross area of 600 ha, is located in the Autonomous District of Yamoussoukro, Côte d'Ivoire, and forms part of the Agro-Industrial Pole Project for the Bélier Region (2PAI-Bélier). Designed for rice and vegetable production, the scheme is affected by the deterioration of its hydraulic infrastructure and the impacts of climate variability, compromising water management and agricultural productivity. This thesis presents a diagnostic assessment and a detailed engineering design (Detailed Preliminary Design - DPD) aimed at proposing a sustainable rehabilitation solution for the irrigation scheme. The methodology adopted was based on the collection and analysis of topographic, hydrological, pedological, climatic and socio-economic data, complemented by field investigations and hydraulic studies to assess available water resources, estimate crop water requirements, and design the irrigation, drainage and pumping infrastructures. The results show that, following the optimization of the layout, the net irrigable area is 497 ha, including 243 ha for rice cultivation and 254 ha for vegetable crops. The proposed irrigation system is an open-channel gravity-fed network supplied by the Bandama Blanc River and the Yaabra Dam, consisting of one primary canal divided into two reaches, 22 secondary canals, and 57 tertiary canals. The selected irrigation design discharge is 3.3 L/s/ha, while the internal drainage network was designed for a drainage coefficient of 3.57 L/s/ha. Water supply is ensured by a pumping station with an installed capacity of 1,470 L/s and a total dynamic head of 15 m. The study also included an Environmental and Social Impact Assessment (ESIA), leading to the development of an Environmental and Social Management Plan (ESMP) to ensure the sustainable implementation of the project. The estimated rehabilitation cost amounts to CFAF 9,627,186,898 (excluding VAT), corresponding to an average cost of CFAF 16,045,311 per hectare (excluding VAT). The implementation of the project will improve water management, increase agricultural productivity, and strengthen the resilience of the irrigation scheme to climate variability.