Bengaluru: A newly-formed lake on the China-Nepal border a few kilometres above Nepal’s Rasuwagadhi, where the ice-rock avalanche that triggered floods in Nepal on August 26 occurred, filled up and began overflowing on Friday (August 28), prompting Nepal to issue fresh flood alerts downstream again.On Thursday, China and Nepal had cautioned people living downstream of the new flood risk this poses.New barrier lake formsFollowing the flash floods that are suspected to have been triggered by an ice-rock avalanche in Rasuwagadhi on the Nepal-China border on August 26 (caused by the breaking off of a section of a glacier into the Lhende, which is a tributary of the Bhotekoshi river), a new ‘barrier’ lake formed in the same area, Chinese authorities had warned on Thursday. The Wire had reported this yesterday.Barrier lakes are formed when leftover debris traps water. According to Chinese authorities, the lake formed at the confluence of the Chhochen Khola and Purepu Tsangpo rivers in Nepal’s Rasuwa district.China’s Ministry of Water Resources had raised alarms about the new flood risk that this lake poses, as it was filling up fast. Authorities in Nepal had also warned of the repercussions of the steadily-filling up lake on Thursday.Due to the flow of the Lhende river being obstructed around 18 kilometres above the Rasuwagadhi border, a lake spanning an area of about 0.11 square kilometres has formed, Nepal’s National Disaster Risk Reduction and Management Authority had said on the evening of August 27.“As there remains a risk of another major flood, all concerned parties in the lower coastal areas are urged to exercise necessary caution and remain highly vigilant,” it had warned.Overflowing lake a risk to rescue effortsAccording to a report by Al Jazeera, the lake’s volume swelled to more than 2.5 million cubic metres on Friday, up from the estimated 1.5 to 2 million cubic metres recorded the day before. According to Reuters, the scale of the lake is equivalent to 800 Olympic-sized swimming pools.As per latest reports, this lake has now begun to overflow, triggering both China and Nepal to issue flood alerts downstream. Reuters reported that residents in Rasuwa district were seen rushing up hillsides to escape any surge in the river level following the overflow.Both countries have also had to temporarily halt their rescue efforts in the area, reported Al Jazeera on August 28, citing Chinese broadcaster CCTV. A report by Associated Press, however, quoted Nepal police spokesperson Abi Narayan Kafle as saying that rescue efforts still continue in Nepal, though rescuers and security personnel remain on high alert. Water levels surge in Indian riversBihar now faces renewed flood threats, with water levels surging in the Ganga, Gandak, Kosi and Burhi Gandak rivers in India, reported PTI on Friday.Meanwhile, the death toll due to the flash floods on August 26 is still climbing. As of 16:00 hours on Friday, the death toll due to the flash floods so far stood at 538, according to Nepal Police.Official spokesperson of India’s Ministry of External Affairs, Randhir Jaiswal, said on Friday afternoon that 400 Indian nationals are safe on the Chinese side, but that authorities have still not been able to contact 320 Indians who were missing in Nepal.“You are aware of the humanitarian assistance rendered by India so far to Nepal in the wake of the recent tragedy. More assistance is in the pipeline. Two aircraft with relief material have left, and a third tranche of relief material is expected to leave this evening,” he said.He also added that as requested by Nepal, India is preparing to send a tunnel rescue team, for which a recce team is being flown in first to assess the equipment required. A medical team is also being sent. India has also offered Bailey bridges along with their associated technical teams so that connectivity can be restored quickly in the affected parts of Nepal, Jaiswal said.