China's $1.5 billion Brahmaputra dam, known as Zangmu Hydropower Station, has raised some serious concerns in India and Bangladesh. Known as the Jamuna river in Bangladesh, any diversion of the waters by China could have some drastic effects for Bangladesh, as it is one of the two lower riparian countries (along with India). Indian ministers and officials are worried that the dam, the largest in Tibet, may reduce water flow downstream, in effect drying up the Brahmaputra.

Located in the Gyaca County, Shannan Prefecture, the dam harnesses the resources of the Brahmaputra which flows through Tibet into India and later into Bangladesh. The China Gezhouba Group, a major hydropower contractor based in Wuhan, said that all six of the station's units were incorporated into the power grid. The dam is said to be the world's highest-altitude hydropower station at 116m high and is set to produce 2.5 billion kilowatt-hours of electricity per year.

China is reportedly building a few other dams but China alleges that they are run-of-the-river projects (hydroelectric power plants that incorporate little or no storage of dammed water) which aren't intended to hold water.

According to former Indian water resources secretary Ramaswamy R. Iyer, such run-of-the-river projects are increasingly becoming a source of intervention. Iyer also believes that China's control of the water supply downstream could affect aquatic life and displace populations living in the region.

According to United Nations estimates, more than half of the world's population will live in water-scarce conditions by the year 2025. A large majority of these people will be in India and China. With the increasing industrial production, expanding consumption and climate change adversities, water supplies will come under more pressure than ever before.

China and India are two of the most populous and fastest growing economies in the world. Of the rivers shared by the two countries, Brahmaputra is the most important and has huge potential for hydropower generation. China has more hydroelectric dams (over 22,000) than any other country in the world and is seen as the world's most aggressive dam builder. With 80 percent of its cities facing a tightened water supply, China is looking to divert the waters to irrigate northern China (part of the Grand Western Water diversion plan to divert water to the dry north). Any diversion of the Brahmaputra waters will likely have the most severe consequences for Bangladesh, a much poorer nation than India.

Bangladesh is a riverine country. The livelihood of millions depends on the availability of water. In total, there are about 250 rivers that crisscross the country. But 92 percent of annual flow is contributed by 57 rivers that originate outside the borders. The unilateral withdrawal of water by upper riparian countries such as India and China can, therefore, cause irreversible damage to the economy and sustenance of the country.

A national water crisis has already begun to threaten the country's biodiversity as more than 50 rivers are on the verge of dying. For instance, the Farakka barrage built by India in the upper part of Padma has had destructive effects for rivers that were fed by the Ganges. With a deal yet to be signed on the Teesta water sharing issue -- a bone of contention between Bangladesh and India -- the livelihood of many in the northern region of Bangladesh gets more and more uncertain by the day. The Bangladesh Joint Rivers Commission (JRC) water flow chart shows that Bangladesh received just 232 cusecs (cubic feet per second) of Teesta water on March 22, the lowest recorded in history. With a worsening nationwide water crisis and unsolved trans-boundary water disputes, the diversion of waters of Brahmaputra could make matters much worse for the poverty-stricken nation, badly affecting the agricultural and fishing industries. Rapid urbanisation, industrial boom, agrochemical use and various other factors are also responsible for exacerbating the water supply crisis.

The construction of the Zangmu may be treated as a case study that helps to highlight the broader regional and international challenges posed by friction over water resources. There is no question that in this case China is in the driver's seat because of the simple fact that China is upstream and has de facto control over the water flow of the Brahmaputra. China is extremely fortunate in this regard because it has a combination of de facto and de jure control in this case -- both of which are necessary under international law. In effect, China controls the Brahmaputra as well as other Himalayan-origin river systems. China's dam-building projects on the Brahmaputra play a vital role in strengthening China's de jure standing. (Christopher, Mark. 2013. Water wars: The Brahmaputra River and Sino-Indian relations. Case study. Newport, RI: US Naval War College, Center on Irregular Warfare and Armed Groups.)

If we are to go with China's dam-building pattern, it can be said that China's downstream neighbours have a legitimate cause for concern. As both China and India go ahead with their dam building projects, it is crucial for the Bangladesh government to immediately address the possibility of China reducing water supply, for which a tripartite agreement between the three nations is imperative. What Bangladesh needs to do is engage in meaningful discussion with both India and China for equitable sharing of the Brahmaputra waters. It is, therefore, time the government started thinking about initiating talks before history repeats itself and other rivers are met with the same tragic fate as the Teesta or the Padma.

The writer is a member of the editorial team, The Daily Star.