The Integrated Irrigation and Food Security Infrastructure Project (PIISA–STP) is a strategic investment designed to structurally transform agriculture in São Tomé and Príncipe by expanding and modernising water retention and distribution infrastructure in a country where only 3% of agricultural areas are currently irrigated. Integrated into the ENDS 2026–2040 axis of Integrated Water Resources Management and Climate Resilience and aligned with the Blue Economy Strategy, the project covers priority areas in the north and north-central regions of São Tomé (Lobata, Lembá and Mé-Zóchi) and Príncipe Island. With water resources exceeding 2.18 billion m³/year, but with limited mobilisation, PIISA–STP is modernising the national water infrastructure by building six dams with a capacity of 23.7 million m³ and expanding irrigation to 2,150 hectares. The result is more productive, efficient and resilient agriculture, capable of increasing food production by 60% by 2035 and reducing dependence on imports by 40%. With an estimated investment of €107.3 million, supported by public, private and multilateral funding, PIISA–STP combines hydraulic engineering, community management, technical training and institutional strengthening to enhance national food security and boost rural economies. The project prioritises areas such as Manuel Jorge, Camavo, Canavial, Godo, Gumbella and Bacharel, mobilising 2,000 ha and generating 3,000 direct jobs, while training 500 technicians and farmers and establishing lasting legal and institutional foundations for irrigation management. This is a structuring project for the climate resilience and food sovereignty of São Tomé and Príncipe, converting water abundance into productivity, income and economic stability.