India's latest mega-dam will disrupt life downstream with sharp each day fluctuations in water levels

“Hey, Rupam, open the door. Take this fish,” a girl called from outside. I used to be sitting within the kitchen of my friend Rupam's house in rural northeast India. It was the center of the monsoon season and it had been raining since morning. The woman will need to have been screaming since the sound of the rain on the tin roof drowned out every little thing else.

The aunt round the corner was standing outside with a big bowl Boriala fishHer husband was fishing on the Subansiri Riverthat flows beside the village, and he had been fishing all evening. “My husband cannot stay indoors in this weather,” she said in Assamese, the local language. “One can catch a lot of fish at this time of the year.”

The Monsoon season has long provided people downstream with an abundance of fish from May to September.

However, that is prone to change as soon because the Subansiri subsea power plantone in all India's largest hydroelectric power plants, is accomplished upstream. fully operational in 2026the dam will change the natural flow of the river.

For many of the day, the dam will hold back water and only allow a small amount to go through, roughly corresponding to the region's dry season. But every night, it would release water for about 4 hours to generate electricity, and the raging river will then rush downstream almost because it does through the monsoon season.

The dam is not going to only hinder the movement of fish, but may even change the way in which people downstream experience the river's flow.

In a 2010 Report on the likely impacts of the Subansiri Lower Hydroelectric Project on the downstream population, experts from three leading institutes of Assam – the central state in northeast India – have identified several problems for the downstream communities, including risk of flooding and erosion, risk of earthquakes, lack of water flow for fisheries and groundwater recharge, and survival of species equivalent to river dolphins.

Now, a decade later, Dam is nearing completionThe key query stays: What will occur to people like Rupam’s neighbors, whose lives and livelihoods rely upon the river?

In 2023, I lived in a village on the Subansiri River. My Dissertation research took me there to research the impact of this dam, under construction since 2005, on the communities downstream.

“Little displacement” on account of “benign” dams

Northeast India has been the main target of hydroelectric power plant construction for the reason that starting of this century. To secure the country’s energy future, Central Electricity Board of India In 2001, the Brahmaputra basin was found to have the biggest hydropower potential – 63,328 megawatts. It was proposed to construct a whopping 168 dams within the region.

This earned the region the nickname “India’s future powerhouse“The Subansiri Lower Hydroelectric Project was the primary project.

The government sees the mega hydropower initiative as a win-win situation. It expects the dams to extend India's energy security while developing major infrastructure networks in one in all India's disputed border regions.

About 80% of the electricity for “India’s future power plant” is to be generated in Arunachal Pradesh, the biggest state in northeast India. China has India’s Sovereignty over Arunachal for the reason that country's independence in 1947.

The construction of dams in Arunachal Pradesh has one other advantage: the very low population density. There are about 17 people per square kilometer and over 80% of Arunachal’s total area is forestThis helped the Indian government to argue that “it is comparativelysmall displacement“from flooding compared to other parts of the country and therefore these projects are harmless.”

However, these projects are in definitely not benign for the people living downstream.

The impact on life downstream

The floodplains of the Subansiri are home to people belonging to indigenous communities and the lower castes of the Hindu caste hierarchy. Mising – the biggest indigenous community within the downstream region – call the river “Awanori”, which implies “mother river”.

As a part of my long-term ethnographic fieldwork, I observed how plenty of Livelihood within the lower reaches – fishing, farming, livestock rearing, salvaging driftwood and transporting people by boat to distant areas – all rely upon the 127-kilometre-long Subansiri River. I interviewed individuals who live there and attended community events to know the necessary role the river plays in on a regular basis life.

Their dependence on the river relies on natural, uncontrolled currents. Once the dam is accomplished, the river flows will probably be National Hydropower Company.

Once operational, the dam will largely block the river for 20 hours a day after which release the water – about 2,560 cubic meters per second – to drive turbines that may meet peak electricity demand between 6 and 10 p.m. each evening. During the 20 off-peak hours, the dam would release lower than a tenth of that quantity of water.

What happens when the flow of the river changes?

When the dam was first proposed, there was no plan to release water through the 20 hours of non-peak demand. Activists argued that interrupting the flow of water would make it impossible for any aquatic animal to survive downstream.

In 2017, the off-peak flow proposal was increased to a spread of 225 to 250 cubic metres per second. That yr, the National Green Tribunal, which adjudicates civil cases related to the environment, ruled asked the National Hydroelectric Power Corporation to make sure a minimum water level for the survival of Ganges dolphinIndia's national aquatic animal. This ruling paved the way in which for construction to resume after an eight-year delay. However, the court didn’t address how the changes would affect people living downstream.

Calculating the minimum flow required for the survival of even a single aquatic mammal ignores many features through which the flow of the Subansiri is vital for humans and other animals.

The dam itself threatens the existence of many fish species downstream, including the golden mahseer. It may even change the flow and sediment supply within the river, and the abrupt and robust current for 4 hours every night will higher scrubbing performance and there’s a risk of abrasion of the river bed and banks.

Traditionally, early-ripening crops are grown within the dry riverbed and on the sandbanks from October to April. Ahu rice and mustard before the monsoon flood arrives. People also graze their cattle on the islands and within the fields after the harvest is brought in.

However, once the dam floods the river for 4 hours every night, the riverbed and sandbars will probably be largely unusable.

The rainy season, when the river is in flood, is the best time for fishing and collecting driftwood. However, the dam hinders the movement of fish and traps the wood behind the dam. So even when the river is in flood on daily basis, fishermen and wood collectors may not give you the chance to profit.

People like Rupam's neighbor know that the Subansiri River is about to alter. They could have to navigate the river more fastidiously, and each evening the water level will reflect the monsoon season.

Will they give you the chance to catch enough fish to share with their neighbors? Only time will tell.