PATNA, Sept. 28 -- A sharp surge in the Gandak river, driven by heavy rainfall over its catchment in Nepal, has raised the spectre of flooding along its course through north Bihar. The water resources department (WRD) has placed districts along the river on high alert after discharge at the Valmikinagar Barrage climbed through Sunday, reaching its highest level of the 2026 monsoon season. According to a senior officer of the WRD, downstream discharge at Valmikinagar has crossed 5 lakh cusec in the evening and it is likely to reach 5.50 lakh cusec, if there is any fresh rains in its catchment areas of Nepal. "The trend remained firmly rising," said the officer, noting that this is the peak for the current flood season. Deputy chief minister cum WRD minister Vijay Kumar Choudhary told HT on Sunday that discharge had already touched 4,24,000 cusecs by 11 am and it was around five lakh cusecs by the evening. The barrage, designed for a maximum discharge of about 8.5 lakh cusecs, has all its gates open. The volume remains below the 2024 peak of roughly 5.62 lakh cusecs, when the river overtopped embankments at several points in East Champaran and Gopalganj. Yet the rapid rise has prompted heightened vigilance. Additional engineers have been posted along both banks, and all field officials have been instructed to remain on 24-hour alert. Any laxity, the deputy chief minister warned, would invite strict action. Water levels at key monitoring points reflected the pressure. At Dumaria Ghat in Gopalganj the river was flowing one metre above the danger mark of 62.22 metres and was reported to be touching the embankment. Other sites on the Gandak-Khadka, Chatia, Rewa Ghat and Hajipur-showed rising trends, though most remained below danger level. Low-lying villages in West Champaran, particularly in Bagaha-II block, had already seen inundation, with several thousand residents affected in the preceding hours. Floodwaters entered parts of the Valmiki Tiger Reserve and overtopped stretches of the Bagaha-Valmikinagar road, prompting the administration to intensify relief arrangements, including community kitchens and the deployment of NDRF and SDRF teams with boats. Officials struck a note of measured reassurance. The relatively lower levels in the Ganga have so far allowed the Gandak's waters to drain more freely into the larger river, reducing the immediate risk of widespread waterlogging or a major flood disaster. "The situation is fully under control at present," Choudhary said. "Nature cannot be predicted with absolute certainty, but there is no need for panic-only for alertness and vigilance." In contrast, the earlier surge on the Kosi has subsided. Discharge at Birpur Barrage, which had peaked at 3,13,595 cusecs early on 26 September, was falling steadily: 2,90,370 cusecs at 2 pm on Saturday, 2,80,185 at 10 pm, 2,20,150 at 10 am on Sunday and 2,13,845 cusecs by 2 pm. Readings at Barahkshetra showed a similar decline....