A reduction in the Teesta River’s water flow during the non-monsoon months has impacted water levels available for irrigation, leading to ongoing disputes between Bangladesh and India. The tension between Bangladesh’s Prime Minister Sheikh Hasina and the Chief Minister of the Indian state of West Bengal, Mamata Banerjee, has led to an impasse in a water sharing agreement between the two countries, leaving both at risk as the water crisis grows. India and Bangladesh face the challenge of sharing a river, an issue which is exacerbated by glacial retreat.
The Teesta River begins in the high mountains of India and flows down to lowland areas of India and Bangladesh. The Teesta supplies one-sixteenth of the water needed by India and Bangladesh for agriculture during the dry season, which runs from February to May. Due to its geography, India has been able to build dams to control or limit water flow to Bangladesh, but not vice versa. Both countries have sought an equitable division of Teesta waters in the past. In 1983, for example, a water sharing agreement was reached, dividing access to the water roughly equally by giving India 39 percent and Bangladesh 36 percent, with the remaining 25 percent unallocated. However, out of fear of water loss in the northern region of the country, the West Bengal government did not approve the treaty, and the agreement was not implemented. Since then, agreements over the Teesta have been unsuccessful.
In 2010, a new agreement was drafted to grant both India and Bangladesh 40 percent of water flow at Gazaldoba Barrage in West Bengal, with the remaining 20 percent for environmental flow, a system for managing water flow below a dam to sustain freshwater, aquatic ecosystems and human livelihoods. However, the state government of West Bengal later opposed the negotiation. Ideally, a treaty between the two countries would ensure water flow during the dry season, secure water for the rest of the year in the river basin, and prevent floods and river erosion during monsoons. The Teesta normally overflows 300,000 cusecs (cubic meters per second) during monsoons, but lately the river has been exceeding 450,000 cusecs, resulting in river erosion.
By 2030, Bangladesh’s water demand is expected to exceed available water supply by 21 percent in the dry season. The Teesta Barrage Project, one of the largest irrigation projects in eastern India, was designed as a network of barrages and canals in six northern districts of West Bengal intended for irrigation, hydropower generation, navigation, and flood control. During dry seasons, barrages, which are broad, low dams that use large gates to control and divert water, are meant to hold back water, but they do not contain a water reservoir facility.
Only certain parts of the project have been completed, including the Teesta barrage at Galzaldoba in West Bengal, which lies 90 kilometers upstream of the Indo-Bangladesh border at Gazaldoba. Bangladesh contests that the Gazaldoba barrage, upstream of Dalia, has reduced water availability during the dry season. After the construction of these dams, large pools of stagnant water formed just upstream of the Teesta Low Dam Project, while downstream there was no water in the riverbed. These man-made hydraulic structures, dams and barrages are meant to impact the water flow and the timing of water release. Unfortunately, poor water management in India and Bangladesh has led authorities to release water at the wrong time since the barrages do not have a water reservoir facility, thereby releasing monsoon water rather than keeping it for dry seasons. Control of the water flow through the Gazoldoba Barrage in India has resulted in the release of excessive water during the rainy season, causing floods and bank erosion.
Why are the dams holding back water upstream when there is a growing demand downstream? Hydropower facilities generate electricity using the water stored in dams, and in order to maximize their profit, these facilities only generate electricity for three to four hours per day during peak hours. Therefore, for about 20 to 21 hours of the day, the water in the dams remains stagnant and unused.
Water flow released during peak hours does not necessarily correlate with the optimal times for farmers to irrigate their land. And there are additional problems with barrages as well. In an interview with GlacierHub, Naveeda Khan, a professor of anthropology at John Hopkins University, explained, “The water that is brought in the water systems enriches the soil because it brings in important silt and clay, and that is a part that people tend to forget. People tend to focus on the materiality of the water and its necessity for irrigation purposes.” The creation of a dam prevents this sediment flow, which disrupts the soil enrichment, she noted. In addition, the delta becomes more vulnerable to sea level rise associated with climate change, because of the lack of sediment that would otherwise have contributed to building up the delta..
Scientists from the central government and the Himalayan state of Sikkim in India have found that the recession of glaciers which feed into the Teesta correlates with the decrease of water during non-monsoon months. Climate change has accelerated the decrease in total area of 84 glaciers in the Teesta Basin. In 2013, the Strategic Foresight Group, a think tank in India, released a report concerning the Teesta Basin that found that 23 of 34 glaciers that contribute to the water flow in the Teesta show evidence of retreat, eight show evidence of advancing, and three remain unaltered. For example, the Gurudongmar Glacier, the main source for the Teesta river, has retreated about 600 meters (one fourth of the total length) from 1987.
Climate change will continue to cause glacial melt melt, as well as increasing evapotranspiration and crop water-demand. Between 2003 and 2012, for example, there has been an increase of about 85 new lakes, which indicates fragmentation of glaciers and faster melting. Studies predict that the Himalayan river catchments will experience more extreme weather events such as cloudbursts and heavy rainfalls, which would increase the rate of soil erosion, landslides and flash floods.
When asked about the effects of climate change on waterflow, Bharat Lal Seth, a former South Asia program coordinator at the nonprofit International Rivers, told GlacierHub, “Climate change is a concern due to the change of the frequency and intensity of rainfall in the region. Across the watersheds we’re recording data that implies more intense rainfall in shorter time frames resulting in unpredictable river flows. The pressures of populations on both sides of the border has resulted in more vulnerable communities shifting to settlements in the river floodplain, putting them at increased danger of floods. Also, less frequent and more intense rainfall, due to changing climate patterns, enhances the challenge of storing rainwater for use in the lean months.”
In an attempt to deal with the Teesta River dilemma, the 2030 Water Resources Group (WRG) recently launched a multi-stakeholder partnership in Bangladesh. The partnership includes representatives from the government, the private sector, civil society, and development partners in an effort to reduce the strain of the demand-supply gap for farmers and improve the quality of water resources for India and Bangladesh. With initiatives started by organizations from India and Bangladesh to better manage the Teesta River’s water supply, India and Bangladesh can work together to combat the damaging effects of climate change and find a solution to the water management crisis.