Bihar chief minister Nitish Kumar on Wednesday urged the Centre to take up with Nepal immediately the issue of ensuring central flow of river below the downstream of the Kosi barrage otherwise the possibility of devastation during 2011 flood could not not be ruled out.

In a letter faxed to external affairs minister S M Krishna, Kumar said in the recent past, Kosi river was one of most problematic rivers.

In the downstream of Kosi barrage, the river has now shifted eastwards and is now flowing by hugging the eastern Kosi embankment, he said, adding it was imperative that the river flow should remain central to exert minimum pressure on either side of the embankments.

To make river flow central, chief minister informed that a scheme of excavation of pilot channel was formulated in the light of recommendation made by Kosi High Level Committee (KHLC), the technical body to suggest undertaking of suitable remedial measures before onset of monsoon every year.

The excavation of pilot channel work was started but unfortunately immediately afterwards, the work was stopped in the 2nd week of April 2011 by Nepalese people and government of Nepal officials, saying that, the excavation of this pilot channel work would adversely affect the Nepal territory, he said in his letter.

Kumar said the eastern Kosi embankment and several spurs situated at various locations were under severe threat during flood in 2010, which could only be saved by doing intensive flood fighting works on a war footing as a pilot channel was excavated in the downstream of Kosi barrage.

That substantially reduced pressure on the eastern Kosi embankment and its various spurs, but the channel subsequently got silted up during the last phase of flood, he said.

The state government was making its best effort to get the work started and a lot of persuasion had been made at the level of union ministry of water resources and the Indian Embassy at Kathmandu.

Kumar said he had already apprised union water resources minister Salman Khurshid about the gravity of the situation.

It was further emphasised that excavation of the pilot channel work to make the river flow central in the downstream of Kosi barrage was not not going to adversely affect the interests of either - India and Nepal.

"The state government is making its best effort to strengthen the eastern Kosi embankment and its spurs on all vulnerable points situated in Indian territory but any work in Nepal territory could not be executed unless Nepalese authorities allow," he pointed out.

Kumar further said he had visited the site on May 27 and in his view all efforts were required to be made to make the river flow central in the downstream of Kosi barrage to reduce the pressure on the eastern embankment.