Hanoi's first metro rail line, scheduled to begin operations in 2016, will face the risk of being flooded during heavy rains, experts say.
They said with four kilometers of underground infrastructure, project developers need to come up with solutions to deal with these risks properly.
Architect Dao Ngoc Nghiem said the chance is high that the railway will be submerged in water. He said the Kim Lien Tunnel, which opened to traffic mid 2009, had experienced flooding and it could happen to the metro rail project as well.
The "Line 3" project, funded by the French government, the Asian Development Bank and the European Investment Bank, is the first of its kind in Hanoi. The capital city plans to develop four other urban railway routes by 2020.
Construction of the project started in September last year. The 12.5-kilometer first phase of the metro line will run from Hanoi's main train station in Hoan Kiem District to the Nhon area in the east of the city.
General consultant for the project, Systra, said a water drainage system has been planned for the metro line. The company, however, admitted that high rainfall levels have not been taken into account.
Marie-Cecile Tardieu-Smith, the French Embassy's economic counselor, said even though the project has been delayed for around one year, it's not unusual, considering this is also a pilot project.
Similar metro projects in other countries have also experienced delays because it is not easy to implement them, she told a press briefing Thursday.
But she said the project will be sped up to make sure it will be finished at the end of 2016 "without any further delay."