The proposed 11,000 megawatt (MW) Upper Siang multipurpose storage and hydroelectric dam project on River Siang in Arunachal Pradesh has been stuck between geopolitical risk and environmental concern. Arunachal Pradesh government’s efforts to convince project opponents about the daunting geopolitical risk posed by the massive Chinese dam project of 60,000 MW on the upper reaches of the Siang in the neighbouring country known as Yarlung Zangbo have failed to cut much ice with organisations in the state opposing the Siang project so far. The continuous push by the Pema Khandu-led government in Arunachal Pradesh for the Siang project has prevented the issue from fading in public discourse. Arunachal Pradesh Deputy Chief Minister, Chowna Mein, during his two-day visit to Siang and Upper Siang districts, addressed the people about the importance of the Upper Siang Multipurpose Project. One of the growing concerns over the Chinese project, which Mein highlighted, is if China builds the dam and diverts Yurlung Zangbo (the Brahmaputra River in the Tibet region) water, it will dry up the Siang River and its distributaries, affecting the aquatic life of the river and the large population in the plains of Assam and Bangladesh which depends on the Brahmaputra River for the irrigation of their agricultural fields. This implies that people in Assam and Bangladesh cannot remain indifferent to the developments in the upper reaches of the Brahmaputra and the cascading impact of the Chinese dam on water security in the region. Mein reiterates the apprehension of his government of China weaponising its dam and releasing large volumes of water in the event of a conflict arising between the two neighbouring countries, causing unpredictable floods in downstream areas of Assam and Arunachal Pradesh, causing lives and properties to be lost. While environmental concerns flagged by organisations opposing the Siang dam are real due to the fragile ecology of Arunachal Pradesh, an environmental impact assessment of the project quantifying the environmental impact in both states can present a clearer picture for the people in both states to make an informed decision. The central government has informed the parliament that it has taken note of China’s announcement of a mega dam project, carefully monitors all developments relating to the Brahmaputra River, including plans by China to develop hydropower projects, and takes necessary measures to protect the country’s interests, including preventive and corrective measures to safeguard the lives and livelihoods of Indian citizens residing in downstream areas. As a lower riparian state with considerable established user rights to the waters of the trans-border rivers, India has consistently conveyed its views and concerns to the Chinese authorities and has urged them to ensure that the interests of downstream states are not harmed by any activities in upstream areas, the parliament was told. India has been insisting on the need for transparency and consultation with downstream countries, and the issue was also raised during the visit of Foreign Secretary Vikram Misri to Beijing for a meeting of the Foreign Secretary-Vice Foreign Minister mechanism between India and China. During the visit, India and China agreed to hold an early meeting of the Expert Level Mechanism to discuss the resumption of the provision of hydrological data and other cooperation pertaining to trans-border rivers, which is a positive development. It has raised hopes for India building a strong case for fair use of the Brahmaputra River, keeping in mind the issues of water security, environmental impact, livelihoods, etc., in downstream areas. India remaining engaged with China on the issue is crucial to address these concerns raised by people in Assam and Arunachal Pradesh. Mien has also reiterated the appeal by the Arunachal Pradesh government to those who are against the construction of the Upper Siang Multipurpose Project to rethink and come to the table for discussion and a solution. He insists that the power generation is secondary and would be a byproduct of the project, and during the lean period, the project will act as a storage for the rainwater that falls in the Indian territory, preventing the river water in Siang from drying up, and in case of the release of a large volume of water by China, the dam in the Siang River will act as a deterrent and release the water in a controlled way, thereby moderating floods downstream. The Arunachal Pradesh government has assured that the government will not impose anything against the will and consent of the people and will properly rehabilitate the displaced people and come up with model villages with all basic facilities. Dialogue and discussion always help in finding solutions to contentious issues. As the issue is about establishing user rights over a transboundary river, the central government inviting the organisations in Assam and Arunachal Pradesh for dialogue with the help of governments in both states can be expected to bring an end to the deadlock and evolve an environmentally sustainable solution.