u/Necessary_Pilot4733

I just watched a Mongabay-India video about the Siang Valley, and honestly, the situation there is wild. I thought this community would want to see what is happening, because the scale of what might be lost is hard to wrap your head around.

The valley is incredibly rich in wildlife, mostly because the river cuts a deep gorge through the mountains that acts almost like a giant greenhouse. The most amazing part is that researchers just rediscovered the red velvet worm hiding in the soil there. It’s an ancient creature—basically a "living fossil" that’s been around for about 500 million years—and it hasn't been recorded by science in over a century. The area is absolutely packed with life, including rare electric-blue ants and hundreds of bird species.

But all of this is on the verge of being destroyed. There is a massive 11,200-megawatt mega-dam planned called the SUMP (Siang Upper Multipurpose Project). If it gets built, it will create a giant reservoir that will permanently drown this ancient ecosystem, ruin the river's natural flow, and displace dozens of local villages.

The local communities, especially the indigenous Adi tribe, are fighting back hard. They are actively blocking the initial government surveys and organizing massive grassroots resistance to protect their land and stop the dam from moving forward.

It is a huge conservation crisis happening right now, and the local resistance could really use more visibility.

The western hoolock gibbon is a small, tailless primate that holds the unique distinction of being the only ape species found in India.They are primarily frugivorous (fruit-eating), making them crucial seed dispersers for the health and regeneration of tropical forests.

The confusion surrounding the gibbons in Arunachal Pradesh's Dibang Valley (and the neighboring Mishmi Hills) is one of the most fascinating taxonomic mysteries in recent Indian primatology.

For biologists, it was a clash between an established geographical rule and deceiving physical appearances.

The Biologists were confused because they believed a major river in Myanmar strictly separated Western gibbons in India from Eastern gibbons. However, gibbons discovered in India's Dibang Valley possessed the split white eyebrows characteristic of the Eastern species, leading scientists to mistakenly believe the Eastern gibbon had crossed the geographical barrier. For 15 years, this physical deception led experts to assume India was home to two distinct ape species, which even halted zoo breeding programs. The mystery was finally solved by a 2021 genetic study, which proved through DNA that the Dibang Valley apes were actually 100% Western hoolock gibbons, and their unique eyebrows were simply a localized physical variation.

It is a taboo to kill this gibbon for the native tribe(idu mishmi) as they resemble humans and are considered brothers.

​I am writing this out of sheer desperation and a need for global solidarity. Deep in the Eastern Himalayas, in the Dibang Valley district of Arunachal Pradesh, India, one of the world’s most pristine and irreplaceable ecosystems is about to be systematically dismantled. The state government has recently revived a series of massive, cascading hydroelectric projects—specifically the Emini (500 MW) and Amulin (420 MW) dams on the Mathun River, alongside the colossal Etalin project (3,097 MW). While these are marketed under the relatively clean-sounding label of "run-of-the-river" projects, the reality on the ground is an environmental nightmare. They require blasting miles of massive underground tunnels, clear-cutting hundreds of thousands of ancient trees, and carving heavy industrial infrastructure into a steep, intact landscape that has never seen this scale of human exploitation. We are staring down the barrel of total socio-ecological severance for a region that serves as a vital climate buffer.

​To understand what is at stake, you have to understand the sheer ecological weight of this region. The Dibang Valley is an internationally recognized Endemic Bird Area and a biodiversity basin home to 600 species of birds—accounting for more than half of all avian diversity found in the entire Indian subcontinent. Because of its extreme altitudinal variations, it creates specialized micro-habitats that support rare flora and fauna found nowhere else on earth. Beyond the incredible birdlife, these valleys are home to the endangered Mishmi Takin, red pandas, clouded leopards, and a unique population of high-altitude tigers that hunt in the snow-capped peaks. Building these dams will subvert and flood the valley-bottom habitats, which act as the absolute lifeblood and migration corridors for these animals. The associated "zone of influence" damage—from extensive road carving, heavy stone quarrying, and the dumping of millions of tons of excavated rock muck directly into the river systems—will permanently choke the aquatic life and fracture this contiguous forest into isolated, dying fragments.

​Beyond the ecological tragedy, building these mega-structures here is a terrifying geological gamble. The Himalayas are the youngest and most volatile mountain range in the world. The rock is inherently brittle, and the Dibang Valley sits squarely in Seismic Zone V, the highest earthquake risk category. Forcing heavy industrial blasting for 5-kilometer and 7-kilometer underground tunnels through these fragile mountainsides will catastrophically destabilize the slopes, triggering massive, unpredictable landslides. We have already seen the devastating proof of concept for this danger: in October 2023, the nearby Chungthang Dam (Teesta Stage III)—built using the exact same concrete gravity, run-of-the-river blueprint—was completely wiped out and washed away by a glacial lake outburst flood, causing downstream catastrophe. Stacking multiple mega-dams in an even more volatile, glacier-fed basin like the Upper Dibang is an ecological time bomb waiting to go off.

​The frontline defense against this destruction is the indigenous Idu Mishmi tribe, whose ancestral homelands encompass these valleys. Their animistic culture and strict traditional taboos against commercial hunting have effectively preserved this biodiversity for centuries; they don't just live in the forest, they are its caretakers. Right now, local youth, student unions, and indigenous groups like the Indigenous Research Advocacy Dibang (IRAD) are putting everything on the line to fight back. They are mounting legal challenges, citing blatant violations of the Forest Rights Act (FRA), and demanding comprehensive, basin-wide Cumulative Impact Assessments. But the state is cracking down hard. Prominent local activists and environmental lawyers are facing police detentions, arbitrary First Information Reports (FIRs), and forced peace bonds just for organizing peaceful public protests and demanding legal transparency. The local community is being stifled, and the power developers are rushing to finalize the Detailed Project Reports.

​I am reaching out to this community because the local resistance cannot fight this state-backed machinery alone. We desperately need international eyes on the Dibang Valley. I want to ask the experts, advocates, and seasoned campaigners here: How can a project like this be stopped when internal democratic and legal avenues are being systematically squeezed?

​Are there international legal frameworks, transnational environmental networks, or global conservation campaigns that have successfully intervened in cases like this? How can we elevate the voices of the Idu Mishmi activists to international human rights and conservation forums? If you have experience fighting mega-infrastructure in biodiversity hotspots, or if you know of organizations, investigative journalists, or legal networks we should be tagging into this fight, please share your insights. We cannot let one of the last truly wild places on Earth be quietly drowned for profit.

https://india.mongabay.com/2026/06/forest-clearance-for-dam-puts-white-bellied-herons-at-risk/

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Not just the local tribal people whose land have been nurtured, protected and made home by our ancestors will be taken away, but also our rare birds will die out in the process.

This is going to be a major setback for Arunachal. Before it's too late, Save Siang!!

Captured by my elder brother who works as a tour guide.

5 dams proposed in that district sadly, three are sure . One of them is 3000+ MW dam Edit- credits insta - apang mihu

I wish the people didn't litter the area. DTP dyke.