Trojena 4.7bn NEOM reservoir project stopped, leaving partial infrastructure challenges

The $4.7bn (£3.7bn) artificial lake and dam project at Trojena, part of Saudi Arabia’s NEOM development, has reportedly been cancelled following partial construction. The decision affects a large-scale hydraulic engineering scheme planned for an arid, high-altitude environment and introduces considerations related to project management, cost, and the handling of incomplete infrastructure.

The scheme was intended as a central feature of a mountain resort and included a 1.7-mile-long artificial freshwater lake supported by multiple dam structures. The primary dam, designed as a roller-compacted concrete structure, was planned to reach approximately 145 m in height, with additional dams forming a reservoir basin. Excavation works had removed significant volumes of rock, some of which was intended for reuse in construction.

With construction activities halted, engineering priorities are shifting toward site stabilisation and risk management. Partially completed structures and excavated areas require monitoring and mitigation to address potential geotechnical and hydraulic risks.

Key technical priorities following the suspension include:

The absence of a completed reservoir alters the site’s risk profile. Instead of operational risks associated with a functioning dam, attention is focused on surface water management, sediment movement, and long-term stability of exposed materials. Potential mitigation measures may include controlled backfilling, drainage systems, and reinforcement of partially constructed elements.

The project also raises considerations related to large-scale infrastructure planning. The proposed lake relied on desalination and water transfer systems, which involve significant energy requirements, particularly in regions with high evaporation rates and limited natural water resources.

The suspension of the project highlights the importance of risk management and contingency planning in complex infrastructure developments.

Future plans for the Trojena site remain subject to further evaluation, including stabilisation and potential alternative use of existing works.