The Siang river, Arunachal Pradesh’s primary water source, has turned black in the past two months, baffling residents. The Siang is the main tributary of the Brahmaputra river that connects to the Yarlung Tsangpo, as the Brahmaputra is called in Tibet, where it originates.

According to a report prepared by the state’s public health engineering department, the turbidity level of the Siang’s waters is several times higher than the permissible limit. Bimal Welly, an executive engineer in the department, said a sample he tested on November 27 showed a Nephelometric Turbidity Unit – a measure of the concentration of suspended particulates in a liquid – of 425. Permissible turbidity for potable water is 5.

“We checked after we got reports of fish dying and even buffaloes who consumed the water dying,” said Welly. “We have been consistently checking the last two weeks and the turbidity has more or less remained constant. We have sent samples for further chemical analysis at the North East Regional Institute of Science and Technology in Itanagar.”

The engineer said an accurate diagnosis of what has led to the high turbidity levels is possible only after the chemical analysis, the result of which is expected soon. A recent report submitted by the State Water Quality Testing Laboratory in Itanagar confirmed that the waters of the Siang are now unfit for human consumption. The turbidity level of the water, according to his report, stood at 482 NTU.

China or earthquake (or neither)?

In the meantime, speculation of possible reasons for the river turning black is mounting. Officials and residents believe China may have something to do with it. This suspicion stems from a widely cited news report about the Chinese government’s purported plan to build a tunnel to divert water from the Yarlung Tsangpo in southern Tibet to the parched Taklamakan desert area in the province of Xinjiang. Arunachal Pradesh Chief Minister Pema Khandu has reportedly asked the Central government to take the matter up with Beijing.

However, the Chinese government has denied it has any such plans, calling the report false.

On Monday, Union Minister of State for Water Resources, River Development and Ganga Rejuvenation Arjun Ram Meghwal said it could be a natural occurrence. He said a preliminary study conducted by the Central Water Commission – responsible for the control, conservation and utilisation of water resources in the country – seemed to suggest the Siang’s waters had turned black after an earthquake in Tibet. An earthquake of magnitude 6.3 had struck the Nyingchi region of Tibet on November 18.

But people living in the Siang valley are convinced there is a “Chinese hand” in the river turning black. “We have got reliable reports in social media that the Chinese are building a tunnel,” said Tasik Pangkam, general secretary of the Siang Indigenous Farmers’ Forum. “This is the first time such a thing is happening, so this can’t be a natural process.”

The murky waters of the Siang river in Arunachal Pradesh where the level of suspended particulates is way above the permissible limit. (Credit: YouTube)
The murky waters of the Siang river in Arunachal Pradesh where the level of suspended particulates is way above the permissible limit. (Credit: YouTube)

Not enough information

Experts say there is not enough information yet to ascertain the reasons behind the phenomenon. Tage Rupa, a geomorphologist at Itanagar’s Rajiv Gandhi University, said the reasons could well be local. “Arunachal is seeing hectic highway construction, so maybe it’s just that,” Rupa said. “A lot of the construction is close to the river, so it’s possible it’s just run-off from construction sites.”

Rupa said only the river’s discharge volume could help geologists say with certainty if indeed Chinese construction was to blame. “If there’s construction really happening on the Chinese side, the discharge volume is likely to decrease, so that should be checked,” he explained.

Data, however, is not easy to come by. In India, flow data of rivers in the Indo-Gangetic and Brahmaputra basins is treated as classified and comes under the Official Secrets Act, often hampering research.

Wilful ignorance?

But with even the waters of the Brahmaputra downstream in Assam starting to turn turbid, criticism of the Union government’s apparent failure to identify the problem is growing. “It is highly disturbing that for days together we have not been able to ascertain what the cause is,” said environmentalist Dulal Chandra Goswami, who has studied the Brahmaputra extensively. “It shows how vulnerable people in the downstream are because of the whims of our politicians.”

Goswami said the current atmosphere of suspense and confusion was symptomatic of the government’s failure to govern an international river like the Brahmaputra. “Ideally, this was a phone call away, but then the basin partners just don’t interact,” he said. “When they do, they argue. This is just no way to handle an international river. This current crisis exposes that there is no framework to negotiate and solve problems so far as the Brahmaputra is concerned.”

Others contend this is the result of wilful ignorance on the part of the government, considering that the Indian state has claimed in the past that it has an extensive surveillance mechanism to monitor any hydraulic interventions on the Yarlung Tsangpo. Back in 2011, the Ministry of Space had said in response to a question in the Lok Sabha that it had satellite images of construction activities along the “entire course of river Brahmaputra”. The reply stated, “Government keeps a constant watch on all developments having a bearing on India’s national interest and takes all necessary measures to safeguard it.”

Mirza Zulfiqur Rahman, a senior research fellow at the Indian Institute of Technology in Guwahati who is working on riverine matters in the North East, asked, “What is preventing the Ministry of Water Resources and the Central Water Commission from coming up with a strong clarification and clearing the air once and for all? Or do conspiracy theories help push Delhi’s agenda of big dams – if the Chinese are building, we must too?”

Rahman said it was time Delhi stopped holding back information on such matters that affect the lives and livelihoods of people in the region. “We need to develop institutionalised responses to crises like these instead of deploying the dams, dredging and China bogeys all the time,” he added. “There ought to be more transparency in information flow from the central agencies.”