A deepwater drainage tunnel to help Dubai manage stormwater and tackle the threat of flooding is in its final pre-operational stage. Dawoud Al Hajri, director general of Dubai Municipality, visited the site on Monday. The drainage system will serve an area of 500 square kilometres and will collect and store water for the next 100 years. Stantec, an architectural and engineering company, said the system was designed to drain 40 per cent of the entire urban area of the city. It will serve the whole of Dubai South, which is home to the emirate’s new airport and the Expo 2020 Dubai site. Water will pass through a 10.3-kilometre tunnel that has an internal diameter of 10 metres and a depth of between 40 and 60 metres. The tunnel ends at the main pumping station near Jebel Ali Port. Excess water can be drained through pumps connected to lines extending 600 metres into the sea. The gravity drain system does not require sub-pumping stations to control the flow of water. This reduced the project cost and will help to save 20 per cent in operating and maintenance expenses, Dubai Municipality said. The project also offers protection to the marine environment. Stormwater will be discharged into the sea only after climate change and the sea level have been taken into account. In January last year, storms and heavy rain caused widespread damage and disruption in several communities in Dubai, while traffic was brought to a standstill by flooding. More than 3,000 Dubai Municipality staff worked tirelessly to drain water across the emirate that week. It is hoped the new drainage system will mitigate the effects of flooding and ensure fewer resources and manpower are needed in the future.