Dubai Municipality, the governing body of the emirate of Dubai, has taken an important step to address the current shortcomings in wastewater management and treatment. Earlier in June, the emirate selected two consortia to bid for major contracts for the Dubai Strategic Sewer Tunnels (DSST) project, which will require a final investment of $22 billion under a public-private partnership framework.
A consortium, led by Etihad Water & Electricity, based in the state-affiliated emirates and working with Saudi Arabia’s Tamasuk Holding and Alkhorayef Water & Power, was selected to bid for Package W, which is estimated to require around $3 billion in investment. The engineering, procurement and construction team of this group includes China Civil Engineering Construction Corp., Shanghai Tunnel Engineering and China Railway 114th Bureau Group. The operator of this equipment is likely to be France-based Veolia.
The second selected bidder is a group led by Saudi Arabia’s Vision Invest and France’s Suez Water Co. They will bid for Package J, which is believed to require an investment of around $2 billion. The EPC work for this package will be carried out by a team formed by China State Construction Engineering Corp. and DeTech Contracting, based in the United Arab Emirates.
The project consists of three packages for which the companies will bid: Package W (Warsan), Package J (Jebel Ali) and a Package for Links, which includes the construction of more than 200 km of deep underground sewer tunnels that will cross the city of Dubai and link the existing facilities with the main W and J tunnels to the deep sewage treatment facilities at Warsan and Jebel Ali. The link pack is currently up for bid.
In earlier stages of development, the DSST project was split into several contracts for Sectors W and J, but these were reconfigured into the current packages and retendered in November 2025.
The massive undertaking requires 3m-diameter tunnels to be built up to 90m below a city that has grown from a small trading port just a few decades ago to a sprawling city of three million people that is home to some of the tallest buildings in the world. Although it has been considered for the past decade, DSST became an urgent issue in April 2024 when Dubai was hit by storms that caused extensive flooding in the city.
The project scope and technical specifications call for the closure of Dubai’s existing fragmented network of more than 150 legacy surface-level pumping stations, which are easily overloaded and become problematic during extreme weather and heat. Deficiencies in sewage infrastructure have led to scenes in recent decades of long lines of sewage trucks running from the city to outlying treatment plants.
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The DSST system will consist of two deep tunnels: the Bur Dubai Deep Tunnel will run 50 km through the most densely populated districts of the city. The Deira Deep Tunnel stretches for 25km, capturing sewage from Dubai’s older neighborhoods as well as Dubai International Airport.
Rather than relying on pumps to move sewage, the DSST will be gravity-fed, with the two main tunnels inclined at a precise downward gradient, allowing sewage to flow naturally. With this design, Dubai hopes to significantly reduce energy consumption and carbon emissions for its wastewater treatment.
Construction of the tunnels at extreme depths will require the use of earth pressure balancing tunnel boring machines and rigorous groundwater control measures. The gravity-fed tailings will end up in two deep terminal pumping stations, each of which will be installed at the existing Warsan and Jebel Ali treatment facilities, where they will be treated, purified and recycled for irrigation uses.
Capital expenditure for these sections of the DSST is valued at $8 billion, but the total life cycle of the system as it expands will reach $22 billion. Financing is structured under a 30-year design, build, finance, operate and maintain (DBFOM) concession model. The financing mix is a strict 80:20 debt/equity ratio that will heavily favor loans from international and regional commercial banks plus the sponsor’s private equity.
Contracts for the construction of the tunnel are expected to be awarded in January 2030. Completion of the tunnel infrastructure is planned for 2030-2056. DSST will have an active operating concession period of 30 years before the definitive return of the network.
