North Bengal: Irrigation dept on alert as pre-monsoon rain surges; Regional Flood Control Room in Jalpaiguri activated on June 1

Jalpaiguri: With persistent pre-monsoon showers bringing 200–300 mm of rainfall across the hills and plains, the Irrigation department has flagged concerns over a potentially critical situation in North Bengal. Engineers are closely monitoring weather patterns in Sikkim, Kalimpong and Bhutan, which influence the region’s river systems. To manage the situation, the Regional Flood Control Room in Jalpaiguri was activated on June 1. It is monitoring conditions in Alipurduar, Cooch Behar, Jalpaiguri and Siliguri districts. Authorities are tracking rising water levels in the Kalijhora and Gajoldoba barrages, along with the release of water from Bhutan’s Tala and Chukha hydropower projects, which affects the Raidak, Torsa and Jaldhaka rivers.

According to the Irrigation department, about one-fourth of the region’s average annual rainfall — around 3,400 mm — has already been recorded by the end of May. In May alone, 400 to 500 mm of rain fell on average, largely due to deep depressions and cyclonic circulations. Rainfall data for 2024 shows a sharp increase across several zones. Alipurduar recorded 4,293 mm, Jalpaiguri 3,177 mm, Cooch Behar 3,306 mm and Siliguri 3,410 mm. Malbazar logged 4,263 mm, Hasimara the highest at 4,952 mm, Banarhat 3,522 mm, Mathabhanga 3,144 mm, Tufanganj 3,079 mm and Maynaguri 2,420 mm. These totals are nearing or exceeding the yearly average—even before the official monsoon.

“The monsoon hasn’t started yet, but we’ve already recorded a large share of annual rainfall,” said Uttam Chowdhury, Superintendent Engineer of the Northern Circle. “From January to June 1, rainfall ranged from 600 mm in Jalpaiguri to 1,060 mm in Hasimara. May’s weather systems caused the surge, and the coming months could overshoot the yearly average.” A yellow alert was issued on June 1 for possible flooding along unprotected sections of the Teesta—from Domohani to the Bangladesh border near Mekhliganj—and the NH-31C crossing the Jaldhaka River. Chief Engineer Krishnendu Bhowmik of the North-Eastern Division noted that rainfall in the hills leads to immediate increases in water discharge from the Kalijhora and Gajoldoba barrages, causing the Teesta’s water level to rise. “We also receive prior alerts from Bhutan when water is released from the Tala and Chukha projects, which raises water levels in the Raidak. Similarly, inflow from Bhutan’s Dorchukha region affects the Torsa in Alipurduar and the Jaldhaka in Jalpaiguri,” he explained. The department remains on alert, using real-time data from 10 departmental gauges, 95 Meteorological department stations and 30 from the Central Water Commission. As of Sunday, the situation is under control.