The Tiger–River Connection: Why India's water future depends on healthy forests

A tiger padding through a forest at dawn rarely brings water to mind. Yet every one of India's 58 tiger reserves sits inside a river system, and many of the small streams that feed the country's great rivers begin inside the very forests tigers call home. Saving a tiger, it turns out, is rarely just about saving a tiger.

Tiger conservation is usually discussed as a matter of forests and wildlife alone. But the existence of tigers is deeply linked to India's rivers, water sources and the water security of millions of people. The dense forests where tigers live also conserve rainwater, recharge groundwater and help maintain the flow of many rivers. Protecting tigers is therefore not only about conserving a single species but also about protecting an entire ecosystem, its water resources and its biodiversity together.

On the occasion of World Tiger Day, this article traces the journey of tiger conservation in India, from a growing population and an expanding network of reserves to the conservation challenges and social and economic impacts that come with them. It also explores why "if tigers survive, rivers survive" is not merely a slogan but a scientific reality for India's environmental and water future.

What World Tiger Day marks, and why it matters

World Tiger Day or International Tiger Day is observed every year on 29 July. It originated at the St Petersburg Tiger Summit in Russia in 2010, at a time when tiger numbers were falling rapidly around the world. In response, 13 tiger range countries came together and set the TX2 target, aiming to double the global tiger population by 2022.

The purpose of the day is not limited to raising tiger numbers. It also raises awareness of the importance of protecting tiger habitats, biodiversity and the wider ecosystems tigers inhabit. Tiger landscapes function much like the lungs of the regions they sit within, providing a vital source of ecological energy for everything that lives there. The day's core objectives include preventing poaching, halting deforestation and reducing human wildlife conflict.

Why this day carries extra weight for India?

World Tiger Day holds greater significance for India than for most other countries since India is home to approximately 75 percent of the world's wild tigers. This is why the Ministry of Environment, Forest and Climate Change has worked systematically for decades to conserve the species, an effort that began with the launch of Project Tiger in 1973.

The birth and growth of project Tiger

Tigers have long been a source of national pride in India, and the Royal Bengal Tiger is the country's national animal. As poaching increased and ecosystems deteriorated, tiger numbers began to decline sharply. In response, the central government launched Project Tiger on 1 April 1973, with the ambitious, scientifically grounded objective of conserving tigers and their habitats together.

The programme began with nine tiger reserves covering approximately 18,278 square kilometres: Corbett in Uttarakhand, Kanha in Madhya Pradesh, Manas in Assam, Melghat in Maharashtra, Palamu in Jharkhand, Ranthambore in Rajasthan, Simlipal in Odisha, Sundarbans in West Bengal, and Bandipur in Karnataka.

Over the following five decades, the programme grew steadily. India today has 58 tiger reserves covering more than 83,000 square kilometres, roughly 2.5 percent of the country's total geographical area. These protected areas have not only supported the growth of the tiger population but have also helped conserve elephants, leopards, gaur, gazelles, crocodiles and hundreds of other wildlife species.

The National Tiger Conservation Authority: A turning point

A series of tiger deaths in the Sariska and Panna tiger reserves between 2004 and 2005 made clear that tigers could not be protected in isolation. The most significant response came in 2006, when the government amended the Wildlife (Protection) Act, 1972, to establish the National Tiger Conservation Authority, or NTCA, now the country's highest body for tiger conservation.

The NTCA sets guidelines and standards for the management of tiger reserves, provides financial and technical assistance to states for conservation projects, and promotes the protection of tiger habitats, wildlife corridors and surrounding ecosystems. It also works to prevent poaching, maintains strict monitoring, works to reduce conflict between humans and tigers, and leads the country's nationwide tiger census, research and monitoring efforts.

Counting India's tigers: A scientific exercise

India's tiger census is considered the largest wildlife monitoring exercise in the world. Conducted roughly every four years, it is jointly carried out by the NTCA and the Wildlife Institute of India.

The census relies on modern scientific techniques, including photographing tigers through camera traps and identifying individual animals by their stripe patterns. It also involves the scientific analysis of tiger footprints, scat and scratch marks found in the wild, supported by GIS and satellite-based habitat mapping.

Statistical models built from millions of camera trap images and thousands of kilometres of field surveys are then used to arrive at the final population estimate. This scientific, transparent methodology has made India's tiger census one of the most reliable wildlife estimates in the world.

Two decades of recovery, in numbers

Project Tiger was launched in 1973, but the tiger population did not show significant growth until after 2000. The country had 1,411 wild tigers in 2006. That number rose to 1,706 in 2010, 2,226 in 2014, 2,967 in 2018 and 3,682 in 2022.

Dr Fayaz A. Khudsar, an environmental scientist at the Yamuna Biodiversity Park in Delhi, told India Water Portal that tigers were once viewed purely as animals to be protected until scientists linked tiger breeding directly to biodiversity, after which the emphasis shifted towards improving entire landscapes rather than isolated patches of forest.

"We know that the Terai region is extremely favourable for tigers," he said. "Therefore, the government began conserving the Terai region. Since tigers migrate from one area to another, corridors were created to connect forests. This increased tiger breeding, and the population grew rapidly."

Where India's tigers live today

Data published by the Ministry of Environment, Forest and Climate Change divides tiger populations across five broad regions: Central India and the Eastern Ghats, the North-east Hills and Brahmaputra Plains, the Shivalik Ganga Plains, the Western Ghats, and the Sundarbans. According to 2022 data, Central India holds the largest tiger population of any region, at 1,439 animals.

Inside India's 58 tiger reserves

India's 58 tiger reserves together cover 84,487.83 square kilometres, made up of a core area of 46,701.29 square kilometres and a buffer area of 37,786.54 square kilometres. The buffer area surrounds the core, protecting it from external pressures while helping balance the needs of local communities with those of wildlife conservation.

These reserves are spread across some of India's most varied natural landscapes, from the Himalayas and the Terai to Central India, the Western Ghats and the Sundarbans. They safeguard far more than tigers alone, protecting the country's most vital forest ecosystems, biodiversity and water catchment areas at the same time. Each reserve carries its own distinct ecological importance.

List of tiger reserves in India

Fact sheet: Key information for each tiger reserve

The price of protection

Over the past ten years, from roughly 2016-17 to 2025-26, the central government's annual budget for Project Tiger, now run as Project Tiger and Elephant, has generally ranged between ₹250 crore and ₹350 crore. Added together, central allocations for this work over the past decade amount to approximately ₹2,800 to ₹3,000 crore. In recent years, the scheme has operated under the broader Integrated Development of Wildlife Habitats framework.

The toll on tigers

Government data shows that 112 tigers died across the country over the past three years. According to figures presented in Parliament on 20 July 2026, 81 of these deaths were caused by poaching, seven by train collisions and 24 by electrocution.

When reserves and villages overlap

A tiger reserve is typically structured as a core area surrounded by a buffer zone, which is in turn often surrounded by villages or farmland. However, many reserves also have tribal communities living within their boundaries. For the safety of these communities, a formal process exists to relocate them outside the reserve.

This applies to Simlipal Tiger Reserve in Odisha, Rani Durgavati Tiger Reserve in Madhya Pradesh, Nagarhole and Kali tiger reserves in Karnataka, Tadoba Andhari Tiger Reserve in Maharashtra, and Achanakmar and Udanti Sitanadi tiger reserves in Chhattisgarh.

The rehabilitation of villages out of a reserve's core or critical tiger habitat is carried out by the respective state governments, with financial support from the central government under Project Tiger. According to data presented to the Lok Sabha, the central government allocated ₹1,350.54 crore for this purpose over the past five years: ₹157.93 crore in 2020-21, ₹170.58 crore in 2021-22, ₹224.20 crore in 2022-23, ₹346.10 crore in 2023-24 and ₹451.73 crore in 2024-25.

Life at the edge of the reserve

Villagers living outside a reserve's buffer zone face a different set of challenges. As tourist numbers at forest camps within reserves continue to rise, the government has been encouraging the growth of these camps, which in turn creates small-scale employment for villagers living nearby, including transporting goods within the forest, driving safari vehicles and providing food for visitors.

Dr Fayaz said that if farmland in these areas were brought into the tiger corridor through genuine community participation, the income of these villagers could increase considerably. He noted that tigers are already commonly sighted in buffer zones and suggested that if farmland within these zones were formally designated as tiger spotting areas, with a share of tourism revenue passed on to villagers, their economic circumstances could improve significantly.

Beyond reserve boundaries: Rethinking conservation

Speaking to the India Water Portal, Dr Chandrashekhar M. Biradar, Senior Ecologist and Managing Director of the Global Green Growth Community of Practices, said: "India's recovery of the tiger population is one of the world's most significant conservation achievements. However, protecting tiger reserves alone is no longer sufficient. The focus should not shift away from reserves; rather, it must expand beyond them, from reserve-centric conservation to integrated tiger-landscape conservation."

He explained that approximately one third of India's tigers live outside designated tiger reserves. Tigers require interconnected networks of core habitats, buffer forests, wildlife corridors, riverine ecosystems and sustainably managed community landscapes to disperse, breed, exchange genetic material and adapt to environmental change. Many reserves, he cautioned, are increasingly becoming ecological islands, surrounded by intensive and often unsustainable land use.

"Conserving a tiger landscape ultimately means protecting the entire living system, forests, grasslands, water sources, prey populations, biodiversity, carbon stocks and the livelihoods of forest-dependent communities," he added. "The tiger is therefore not merely a species to be counted; it is an indicator of the ecological integrity and long-term security of India's landscapes.

The tiger water connection

The presence of tigers is widely understood as a marker of biodiversity, but tigers are also directly linked to water. According to Dr Fayaz, rivers across India face several pressures on their health, but three issues stand out as the most significant threats to their environmental sustainability and resilience: insufficient flow, degraded catchments, watersheds and basins, and untreated wastewater discharge. The solution to all three, he said, lies in restoring these ecosystems by allowing natural ecological processes to take hold again.

"Tiger is a keystone species and plays a critical role in initiating this process," Dr Fayaz explained. "A massive grassland is needed to support the tiger's prey, and so the forest grows, allowing numerous small channels to flow and form a small river. Many such rivers then form a large river that sustains humanity."

Together, the observations of Dr Fayaz and Dr Biradar point to a clear conclusion: rivers will endure only if tigers endure. The evidence for this is visible on the map as much as in the science. Tiger reserves around the world sit within river systems, and many of the streams feeding these rivers originate inside the forests tigers inhabit.

Rivers that flow through tiger country

India's tiger reserves are not only strongholds for big cats; they also protect some of the country's most important rivers and watersheds. The Ramganga flows through Corbett, the Ken through Panna, the Brahmaputra through Kaziranga, and the Krishna through Nagarjunsagar. These rivers sustain forests, wildlife and millions of people downstream, underlining the close link between tiger conservation and water security.

How forests safeguard water

Tiger landscapes are not simply habitats for a single species; they form the foundation of entire ecosystems and of water security itself. Dense, healthy forests protect catchment areas, allowing rainwater to reach rivers and groundwater sources gradually rather than all at once. These forests support groundwater recharge, sustain wetlands and natural springs, and help retain soil moisture. During heavy monsoon rainfall, the same forests reduce flood risk by slowing the rapid flow of water across the landscape.

The threats that could undo this progress

Asked about the biggest threats facing India's tiger landscapes, Dr Biradar said: "The foremost threat is habitat fragmentation and the progressive loss of connectivity caused by highways, railways, power lines, canals, mining, urban expansion and other infrastructure. Even where tiger numbers are increasing within well-protected reserves, the deterioration of corridors can isolate populations, restrict gene flow and increase human–tiger encounters as dispersing animals enter farms and settlements."

"Other serious threats include habitat encroachment, forest degradation, prey depletion, illegal hunting and wildlife trade, forest fires, invasive species, unregulated grazing and excessive extraction of forest resources," he added. "Climate change is an additional and growing threat, particularly sea-level rise, salinity and erosion in the Sundarbans, along with increasing drought, heat and fire risks in other landscapes."

Dr Biradar further pointed out that India's total tiger population may continue to rise even as some smaller populations, habitats and corridors quietly disappear. Conservation success, he argued, must be measured not only by the number of tigers but also by the extent, connectivity, ecological health and resilience of the landscapes that support them. India, he said, now needs cumulative landscape-level planning, scientifically designed wildlife crossings, habitat and prey restoration, technology-enabled monitoring, timely conflict compensation, and genuine community stewardship built around equitable livelihood benefits.

A new model: Biodiversity credits

Asked how tiger reserve landscapes could be better protected, Dr Chandrashekhar said: "India, which hosts over 70% of the world's tigers along with leopards, Asiatic lions, and snow leopards, faces increasing threats to wildlife from habitat fragmentation, deforestation, and human-wildlife conflict. Biodiversity credits offer a game-changing solution by financially rewarding communities, forest dwellers, tribals and conservation agencies for protecting and restoring key ecosystems like wildlife corridors, grasslands, fringe agroforestry, food forests and buffer zones. For instance, buffer areas around Project Tiger reserves could be enrolled in biodiversity credit schemes, allowing local communities to earn income through conservation-linked livelihoods rather than extractive practices like grazing or logging. These credits could also support rewilding, agroforestry, and ecotourism in states like Madhya Pradesh, Karnataka, and Uttarakhand, where big cat populations remain vulnerable."

A shared fate

India has achieved remarkable success in tiger conservation over the past five decades. Through Project Tiger, scientific monitoring, an expanding network of reserves and sustained local conservation efforts, the country is now home to approximately 75 percent of the world's wild tigers, an achievement built on consistent policy, long-term thinking and sustained institutional effort.

Yet the challenges ahead are real, chief among them the continued encroachment on wildlife corridors. Narrowing these corridors to build roads and highways fragments tiger habitat just as surely as deforestation does. In the years ahead, conservation in India will need to focus not only on raising tiger numbers but also on protecting entire tiger landscapes, river systems and forest ecosystems together.

Amid all these numbers, budgets and policy frameworks, one thing is worth holding onto: if tigers do not survive, neither will the rivers that quietly depend on the forests they call home.