All major drains in Patna will get concrete covers and roads laid over them in a move meant to decongest traffic, make roads wider and ensure a smoother ride for commuters.

The Patna divisional commissioner had on Monday announced the development of a 6km road on Saidpur Nullah, which runs parallel to Ashok Rajpath. Eight more nullahs will follow suit.

The Bihar Urban Infrastructure Development Corporation (BUIDCo) is chalking out plans to construct concrete culvert boxes - similar to that over Ashiana-Rajiv Nagar Nullah - to pave roads over them. Most roads over the drains would be four-lane and are expected to help ease traffic snarls in the city.

"The big drains or nullahs take up a lot of space beside the roads," said a senior BUIDCo official. "Considering the space crunch on existing city roads, the urban development and housing department plans to develop roads over the drains by covering them with concrete. Waste water would flow in the drain underneath, while vehicles would ply over the concrete covers."

Experts hailed the move to develop roads over drains.

"Once the drains are covered, the residents would not be able to dump garbage into the waterbodies," said R.S. Choudhary, the last serving chief town planner of Bihar who retired in August, 2004. "That would ensure unhindered movement of water in the drains and lesser possibility of waterlogging. However, it needs to be seen whether or not the employees of the Patna Municipal Corporation (PMC) are able to clean the underground drains."

The concept of roads over drains was first implemented in the city with the development of Boring Canal Road. After that, the Ashiana-Digha road was also expanded to a four-lane road by covering the drain along its side. The 1.85km drain was covered with concrete culvert boxes over a period of six years and vehicular movement began over it from September 2015.

"Four-lane traffic movement would be made possible on all eight drains once they are covered with concrete," said the BUIDCo official. "Most drains are around 20feet wide, which would allow development of two-lane roads over them. The roads running along drains already have two lanes. Thus, all roads would turn four-lane after covering up the drains with concrete."

The three road-over-drain projects being taken up by BUIDCo on an immediate basis include Saidpur, Serpentine and Kurji nullahs.

"The detailed project reports (DPRs) for development of roads over the three drains are expected to be ready by the end of March. We are also working on the selection of consultants for the remaining five nullahs. Once the DPRs are ready, we would submit the same with the state government to seek administrative and financial approval," said the BUIDCo official.

The PMC is supposed to undertake monsoon preparedness work, including repair of manholes/catchpits and drainage cleaning from February 15 and complete it by June 10. However, the work mostly starts from April or May.

The city currently has a network of 535 drains, including nine big, 14 medium and 172 small ones. Apart from that, there are small drains constructed by residents on their own, which flow directly into the Ganga or other waterbodies.