The Bengal irrigation department has formally sought financial assistance and technical support from the Centre for a detailed Teesta river study, aimed at mapping changes in the river basin after the glacial lake outburst flood in Sikkim in October 2023 and informing a long-term flood-management plan for north Bengal.
The office of the chief engineer of the department’s North-east Circle sent a written proposal on Thursday to the Flood Crisis Management Committee constituted for the Teesta under the Union Ministry of Jal Shakti. The proposal seeks approval and funding for a survey covering the river’s descent from the hills into the plains and extending towards the Bangladesh border.
The proposed study would cover approximately 62 to 65 kilometres of the Teesta basin, including stretches around Kalimpong and Sevoke, as well as areas in Jalpaiguri and Mekhliganj. Officials and engineers have discussed conducting the work through the Space Applications Centre under the Department of Space and the Northeastern Council, although the proposal is now before the central committee for consideration.
The study is intended to examine how the Teesta’s channel and riverbed have changed between the mountainous terrain and the plains. Researchers would assess the intensity and velocity of the river’s flow during the monsoon and dry seasons, along with the quantity of sand, stones, pebbles and sediment being transported and deposited along different stretches.
The proposal also includes an assessment of multiple channels, riverbed depth and the water-holding capacity of the river. The river’s morphological condition would be examined across winter, summer and monsoon, after which a detailed report would be prepared for the state government, according to the report submitted by The Telegraph India.
The department has identified several stretches where the Teesta has changed course over the years. These include areas from Sevoke towards Malbazar, Changmari in Kranti, Milanpally and Birenbusty near the Gajoldoba barrage, Bakali in Mainaguri and sections towards Mekhliganj.
The proposed research would combine satellite imagery from previous years with field inspections. The department has said that GIS-based software, echo sounding, river-wave systems, remote sensing and digital photogrammetry would be used to assess the river’s changing morphology. The findings are expected to support decisions on dredging, new embankments and the installation of spurs at vulnerable locations.
The proposal follows the October 2023 glacial lake outburst flood in Sikkim, which has been identified by the state department as a significant reason for assessing the latest condition of the Teesta. The study would therefore link changes in the upper basin with flood-management requirements in the plains, where settlements and infrastructure are exposed to shifting channels and changing flow patterns.
Anil Kumar Arya, an executive engineer of the Central Water Commission and a member of the Flood Crisis Management Committee, said the committee would not undertake the proposed study or construction work itself. “The committee will examine the proposal submitted by the state irrigation department and communicate its decision,” he said.
The next formal step is the committee’s examination of the state’s proposal. Approval and financial assistance from the Centre would be required before the proposed multi-season survey and associated technical assessments can begin.
