The Public Works Authority (Ashghal) appointed CDM Smith to provide construction supervision and post-contract professional consultancy services for the Construction of Flow Diversion in Al Tarfa, Legtaifiya and Jelaiah (C830), a critical component of Doha’s wastewater infrastructure expansion program. The project supports a broader strategy to modernize wastewater collection systems across northern Doha by diverting flows from existing pumping stations into a gravity-based sewer network connected to the Doha North Sewage Treatment Works. Once complete, the scheme will enable the decommissioning of five existing pumping stations, reducing operational and maintenance requirements while improving long-term system reliability.

CDM Smith’s services included project administration, construction supervision, stakeholder management, commercial management, quality assurance and health and safety oversight. The project involved construction of approximately 5.7 kilometers of gravity sewer pipelines using both open-cut and trenchless installation methods, 64 deep manholes, foul sewer rising mains, CCTV inspections and pumping station decommissioning works. The team also coordinated utility interfaces, traffic management approvals and environmental compliance activities within a dense urban environment that included residential communities, schools, mosques and major transportation corridors. Through proactive technical review and construction management, CDM Smith helped implement innovative solutions, including the use of precast manholes to accelerate delivery and specialized microtunneling approaches (between 22 to 26 m deep) to address challenging ground conditions. The completed project strengthens Doha’s wastewater network while supporting future population growth and sustainable urban development.