This article investigates the juncture of hydropower and nuclear engineering traditions at the South Ukraine Energy Complex in the USSR from the late 1960s onwards. Engineers from the hydrotechnical design institute Gidroproekt played a key role in the envisioning, planning and realisation of this unique project. It combined a nuclear power plant and its cooling water reservoir with a pumped-storage hydropower plant and an accompanying run-of-river hydropower plant, allowing for potential synergies with irrigation and pisciculture. A mixture of hydraulic and nuclear technocratic traditions manifested itself in a large-scale attempt to change the natural environment as proof of Soviet technological superiority.