Dubai plans to have a new deep-tunnel sewerage system costing around Dh30 billion ($8 billion) by the year 2025 as part of efforts to meet long-term needs for used water collection, treatment, reclamation and disposal, a report said.

Dubbed the 'Development of the Century', the project should save millions of dirhams worth of maintenance costs and contribute to providing millions of cubic metres of irrigation water to the benefit of the mega projects set for execution over the next years in the emirate, reported Wam, the Emirates official news agency.

Hussain Nasser Lootah, director general of Dubai Municipality, said the authority has finalised the landmark multi-phase development's feasibility studies and construction work should start between 2019 and 2025, with its initial costs estimated at Dh30 billion ($8 billion).

A consultancy is now conducting the project's initial design concept which should be received by Dubai Municipality in February 2018 before being thoroughly studied and referred to the municipality's technical committee for review and endorsement, said Lootah.

The project will be executed over six years in two phases, with the first to be launched in Deira District and the second in Bur Dubai, he said, noting that it will significantly reduce the running cost of the sewerage system, as it will replace the pumping stations that require electricity to run and periodic maintenance.