China has blocked a tributary of the Brahmaputra river in Tibet to construct its Lalho hydro project, reported PTI. The move may impact water flow in India. Any hydropower project on Brahmaputra or its tributaries make the northeastern states of India vulnerable to floods as well as lack of water, according to India Today.

The Lalho project, the construction of which began in 2014 and is likely to end by 2019, will come up on Brahmaputra’s tributary, Xiabuqu river. According to state-run Xinhua news agency, this is China’s most expensive hydropower project. Zhang Yunbao, the project's administration bureau head, said a sum of 4.95 billion yuan (Rs 4,923 crore) has been earmarked for the project in Tibet’s Xigaze region.

Xigaze is about 200 km from Sikkim and it is from here that the Brahmaputra enters Arunachal Pradesh. Apart from India, Bangladesh will also face repercussions of this construction. However, the extent of the impact is not clear yet. This is not the first time that China’s dam construction has had an impact on India. The Zam Hydropower Station on the Brahmaputra, which is touted as the largest in Tibet and became functional last year, had raised many concerns. China built its first dam on the Brahmaputra in 2010 and three more are under construction, reported India Today.

In March this year, Union Minister of State for Water Resources Sanwar Lal Jat said that India had taken up the matter with China when the latter allayed fears of restricting water flow because of its projects. There is no treaty between India and China regarding sharing water, but the two countries have devised an Expert Level Mechanism on trans-border rivers, reports said.

This blockade of the tributary comes as India decided to review the decades-old Indus Waters Treaty with Pakistan, after the attack on an Army base in Uri, Kashmir, which it suspects was sponsored by Islamabad. Prime Minister Narendra Modi had said "blood and water cannot flow together".