Hydraulic performance and water management challenges in an irrigated perimeter in Côte d'Ivoire

ABSTRACT Since the 1970s, Yamoussoukro has been a key zone for irrigated rice cultivation. The N'Dakonankro-Kpoussoussou irrigation scheme was developed to promote food self-sufficiency, but faces growing water management challenges. This study assessed its hydraulic functioning through Rapid Participatory Diagnosis and Planning (DPRP), hydrometric measurements, and water productivity determination over three growing seasons. Results revealed major malfunctions due to inadequate maintenance and failed local governance structures. Transport efficiency averaged 87.9%, but varied significantly between canal banks: 92.9% on the left versus 82.9% on the right, with one critical section showing only 58.1% efficiency. Plot application efficiency varied widely between campaigns (43.5, 83.2, and 67.2%), reflecting a mismatch between water supply and demand. Overall irrigation efficiency stood at 56.8%, while water productivity reached only 0.32 kg/m³, nearly half the reference value (0.6 kg/m³). Chronic over-mobilisation was identified, with approximately 885,000 m³ mobilised per cycle regardless of actual needs. These results point to inefficient resource management resulting from combined technical, organisational, and socio-economic failures, compromising rice production potential in Côte d'Ivoire.