Ashghal to upgrade tunnel designs to prevent flooding

The Public Works Authority (Ashghal) is studying plans to upgrade its tunnel designs as part of flood mitigation efforts that aim to address excess surface water during the rainy season, an official has said.According to engineer Yousef al-Emadi, manager of the Highway Projects Department at Ashghal, the authority designs tunnels based on the worst or highest floods that the country had experienced in the past decades.Al-Emadi made the statement after Ashghal partially opened earlier this month Qatar’s “longest and deepest bi-directional tunnel,” which is part of the construction of the Al Rayyan Road Upgrade Project Phase 2.The 1.5km tunnel, which is a major link between Bu Erayen and Lebday Streets, spanning the Al Mokafaha and Lebday Interchange, sits 25m below ground level, making it the longest and deepest bi-directional tunnel in Qatar.“This tunnel was built according to the design; usually our designs for all the tunnels in the state of Qatar are based on what is called ‘from one to 50’, which means the record of the highest and worst rains the country had experienced in the past 50 years,” al-Emadi told Gulf Times.The bi-directional tunnel also forms part of the complex three-level Al Mokafaha interchange. On the ground level is a signalised junction, which facilitates traffic movements in all directions, including Al Waab, Bani Hajer, and Doha. Beneath this is an underpass that allows road users to travel seamlessly between Doha and Bani Hajer. The tunnel is beneath the underpass, both of which replace the old roundabout.But al-Emadi noted that Ashghal has plans to improve its tunnel designs to prevent flooding: “Now there is a plan under study to upgrade these designs. Instead of ‘one to 50’, it would be ‘one to 100 years’”.Also, al-Emadi said Ashghal is working on an outfall project in the Abu Hamour area, which would pump rainwater to the sea.“For the time being, we are looking forward to finishing the Abu Hamour outfall in order to release a little bit the pressure on our drainage network and pumping stations,” al-Emadi said, adding that Ashghal aims to complete the project “by 2020 or 2021.”In November 2018, Qatar News Agency (QNA) reported that the Mesaimeer tunnel, which is expected to be completed by the end of 2021, will link existing and future drainage networks along the areas it traverses, and is expected to absorb surface water from different locations, estimated at 170sq km, which will reduce rainwater collection, particularly in various tunnels.