© Shutterstock / Suriya99 / WWF
Rivers are lifelines for people and nature. From our earliest civilizations to the mega-cities of today, we have built along rivers due to the benefits they provide - water for drinking and irrigation,  fisheries, fertile floodplain fields, stable deltas, transportation and livelihoods - as well as their central role in so many of our cultures. They are also home to incredible biodiversity and sustain countless other species on land and in the ocean. Each week, we will profile one of the most extraordinary rivers.

© Roland Dorozhani


#22 Vjosa

Rising as Aoos in Greece, the Vjosa River free-flows for over 270km through Albania until it drains into the Adriatic sea. The river boasts a variety of habitats as it crosses through high canyons, islands, and extensive wetlands in its lower stretch. Its basin safeguards incredible biodiversity, from migratory fishes and birds to endemic endangered plants, amounting to over 1,100 species. Home to such a wealth of wildlife, Europe’s last wild river also provides various economic and cultural benefits to local communities, including around 60,000 Albanians living along its shores. Its pristine beauty and potential for adventures drive a growing tourism industry. But the Vjosa is at the looming risk of fragmentation due to hydropower dams, like many other rivers in the Blue Heart of Europe. WWF’s 10 Rivers at Risk report released in September 2021 highlighted these dams would cause significant social and environmental damage in return for negligible amounts of electricity. But thanks to campaigns by local communities and international organisations, the future looks brighter for the Vjosa. Recently, Albania’s government and courts axed two destructive hydropower projects. And at the beginning of June 2022, the government declared the Vjosa River and its tributaries a future national park - a critical action to support the preservation of one of the last wild rivers in Europe. But we need to keep fighting for systemic change. This alarming study from 2020 shows that over 500 dams are planned in Protected Areas, and dead dams often come back from the dead. A combination of solutions is what we need to keep the Vjosa free-flowing. Besides halting high-impact hydropower and transforming key biodiversity areas into national parks, countries should choose a 21st-century path. This path is to invest in renewable alternatives, like solar and wind, that are LowCx3 Low cost, low carbon, and low conflict with rivers and communities. Together, these solutions would keep the Blue Heart of Europe beating for the benefit of people and nature.

© Patrick Bentley / WWF-US


#21 Cuando

The Cuando (alternately spelled as ‘Kwando’) River is one of the few rivers worldwide that remain undisturbed and naturally connected. Extending through an area of dry sandy woodland, its Basin is a "linear oasis" – it serves as the only water source within thousands of square kilometres for wildlife and people in southwest Africa. Rising in a remote area in Central-Southern Angola, the Cuando flows for over 220 km along the country's border with Zambia, crossing through Namibia and ending in the Linyanti Swamps on Botswana's border. Estimates show that over 250,000 people live in the Basin, many of whose subsistence depends on Cuando's healthy waters and flows. The Basin also safeguards savanna and open woodland habitats that serve as vital migration corridors for elephants, zebras, buffalo, and wildebeests. The River's banks are also home to many endangered species, such as the Southern African cheetah and Cape wild dog. As an important headwater tributary of the Zambezi River, it provides critical water resources to the heart of the Kavango-Zambezi Transfrontier Conservation Area (KAZA TFCA) - the world's largest transboundary conservation area. Due to such transboundary nature, coordinated efforts between the neighbouring nations are necessary to ensure sustainable management, use, and protection of the shared resource. Since 2020, WWF has embarked on a process to assess the state of the river basin. To strengthen transboundary governance in the Basin, WWF-US, WWF-Zambia, the Zambezi Watercourse Commission, the KAZA TFCA Secretariat, USAID, and the United States Department of State have developed the Cuando Basin Report Card, the State of the Cuando Basin Report, and the Kwando Joint Action Group. These efforts will help ensure inclusive and sustainable water resource management and increased water security for the benefit of people and nature in the Cuando River Basin and downstream in the Zambezi Basin.

© Stephen Kelly / WWF-US


#20 Ayeyarwady

Flowing for over 2000km from north to south, the Ayeyarwady River is one of Southeast Asia's last two long, free-flowing rivers. A lifeline for 34 million people in Myanmar, the river is also the engine of the country's economy. The Ayeyarwady's natural flow of water, sediments, and nutrients provides water for communities, cities, and companies to sustain productive freshwater fisheries. It also nourishes the country's rice paddies and keeps its fertile and densely populated delta from sinking and shrinking. The Ayeyarwady supports rich biodiversity, including fewer than 80 of the iconic and critically endangered Irrawaddy river dolphins. The river is one of the only places in the world where dolphins fish together with humans - a traditional method called "Cooperative fishing". But all these benefits are at risk. Unsustainable fishing decreases food sources significantly and kills other species (e.g., Irrawaddy river dolphin), while pollution and navigation threaten the Ayeyarwady's health. Loss of sediment upstream due to hydropower dams and sand mining is the main impact on Mekong's delta and are barriers to fish migration and nutrients. The world needs to factor in the diverse benefits of free-flowing rivers as well as the true social and environmental costs of hydropower on rivers, nature, and people. Renewables like solar and wind are low carbon, low cost, and low impact. These energy sources can provide power to the 50% of Myanmar's population who lack access to electricity while helping to keep Myanmar's lifeblood flowing freely. 



#19 Vistula

The Vistula is Poland's longest river, stretching for more than 1000km from the Carpathian Mountains to the Baltic Sea. Home to over 23 million people, the river has been at the heart of national life for hundreds of years. It has provided an important trade route in Europe, known by many as the "Queen of Polish rivers". Its basin covers close to 60% of Poland, mostly agricultural land. The river also provides for tourism and fishing – it is a corridor for migratory fish like the sturgeon and sea trout. Some sections of the Vistula are among Europe's most exceptional areas of natural value, including the Biebrza River valley and Luknajno and Karas Lakes, which harbour rare species of plants and animals. But all this is at risk. In addition to pollution, old and possibly new dams threaten to wreck much of what's left of the river's natural cycles. WWF's 10 Rivers at Risk report highlights a proposal to build a dam across the lower Vistula to create a reservoir to produce energy and, the developers claim, reduce flood risk. But environmental impact assessments show no impact on flood prevention. The new dam will supposedly protect an obsolete dam built in the 70s, but the old dam worsens the risk of flooding. This project would cost taxpayers €1 billion while only generating short-term profits for the developers rather than long-term benefits for Poland's people. Cutting off nearly 70,000 km of the river system from the Baltic Sea, the new dam will drastically alter natural flows and water quality and negatively affect local communities, tourism, and migratory fish populations that have already fallen by 93% across Europe. But there are alternatives: 44 wind turbines could generate the same amount of energy with none of the destructive social and economic impacts. Poland can opt for LowCx3 renewables - low carbon, low cost, and low conflict with rivers and communities –, scraping the new dam and removing the old one, which would cost less than a tenth of the current proposals. This 21st-century path would help tackle climate change, reduce flood risk and restore the health of the entire Vistula, benefiting people and nature across the country.

© Ghulam Rasool



Flowing 2800km from the Himalayas towards the Arabian Sea, the Indus River is one of the largest transboundary rivers in the world: shared by Pakistan, India, China, and Afghanistan. Its basin is the lifeblood of more than 300 million people who depend on the river for water supply, food security, and power generation. It sustains one of the world's largest contiguous irrigation schemes in Pakistan, on which the country relies for all sectors of the economy. Pakistan's Indus basin is also home to more than 225 significant wetlands - of which more than 19 are Ramsar Sites - and rich biodiversity, including over 190 freshwater species and many migratory and endemic species like the sacred Golden mahseer and the Endangered Indus river dolphin. But all this is at risk. Excessive water use - especially for agriculture in Pakistan, which consumes close to 90% of all currently available freshwater supplies - unplanned urban growth and upstream interventions like dams/infrastructures lead to a decrease in freshwater availability and increased the mismanagement of water and pollution in water bodies. The Indus delta is sinking and shrinking due to sediment loss, while, at its source in the Himalayas, climate change is melting the glaciers that keep the river flowing. Floods also create substantial losses, such as the devastating 2010 flood in Pakistan that took the lives of over 1,700 people and caused an estimated US$10 billion of economic damage. Pakistan and its people are particularly vulnerable to damages to the Indus basin's health, economically and regarding national disputes over its headwater areas. But not all is lost. Stakeholders need to tackle water security challenges for the basin's sustainable management. WWF and partners work to safeguard the Indus River Basin Landscape via initiatives like the River Dolphin Rivers, Resilient Asian Deltas and Asian Flyways, Collective Action, Water replenishment, water stewardship with the cotton and textile sectors, and our largest NBS project - Recharge Pakistan.

© Michel Gunther / WWF



Running through Brazil, Paraguay, and Argentina, the Paraná River flows for over 4500 km, having the second-largest basin on the continent. The River, its tributaries, and wetlands are of great economic, ecological and cultural importance to the region and the world. It forms geographic boundaries and links inland cities to the Atlantic Ocean. The River is named after the Tupi-Guarani Indigenous peoples, who first inhabited the basin, meaning "that resembles the sea" or "like the sea". Rising on the south-central Brazilian plateau, it is formed by the confluence of the Rio Grande and Paranaíba Rivers. After some 3500km, it unites its waters with the Paraguay River and flows for over another 1000km until it meets the Uruguay River, forming the extensive Río de la Plata estuary. The Paraná River Basin is home to some of South America's major population centres, harbouring approximately 100 million people who depend on the rivers' waters as a source for drinking, irrigation for agriculture, energy, industries, traditional fisheries, aquaculture, recreation, and tourism. The basin safeguards ecologically critical habitats in its Brazilian upper part like the Cerrado, Pantanal, and Atlantic Forest, and fantastic biodiversity, including the Neotropical otter and more than 450 fish species, like the migratory fish "Dourado". But all of this is under threat – much of the length of the Paraná and its tributaries have been impacted negatively by rapid urbanisation, agriculture, and hydropower development. The River holds the world's second-largest hydroelectric installation - The Itaipu Dam in Brazil, which reservoir has flooded around 100,000 ha of land. The basin's health also suffers from pollution, invasive species, and climate change. In 2021, the River's water levels hit their lowest since 1944. Urgent action needs to be taken to create strategies to restore and maintain Paraná River's health and flows on which people and nature rely.

© Nasa


#16 Imfolozi

South Africa’s Imfolozi is not one of the world’s most famous rivers but it should be! Not only does its basin include the extraordinary St Lucia wetland World Heritage Site, but the river is also the lifeblood of the Hluhluwe-Imfolozi Park - which famously saved the White rhino from extinction. As for the iMfolozi - its Zulu name is thought to describe the zigzag course of the river and its tributaries. Arising in the province of KwaZulu-Natal, the river is formed by the confluence of the Black and White iMfolozi rivers, before it meanders for 40km down to the Indian Ocean at St Lucia - a mix of lagoons and dunes that houses hippos, crocs and a wealth of birdlife and was saved at the end of last century from destructive mining by a huge public campaign. While the river basin is primarily given over to agriculture, particularly sugar cane farming, it still boasts incredible biodiversity in the Hluhluwe-Imfolozi Park, which is home to elephants, lions, buffalo, leopard and a host of non-Big 5 species as well as white and black rhinos. The Imfolozi’s waters are also essential for cities and irrigation for sugarcane and forestry. But all this is at risk. Large-scale cultivation, coal mining, and land degradation have altered the river's natural water flows and levels, while the St Lucia estuary has been separated from the river since the early 1950s due to canalisation, and the estuary now suffers from insufficient freshwater supply, worsened by increasing droughts. Fish and crustacean stocks in Lake St. Lucia have collapsed, while the loss of this nursery area - due to the estuary mouth silting up - has also impacted catches in adjacent coastal waters. Scientists say that the only way to assure the estuary's health is by reconnecting it to the river. And it’s not just the estuary that needs a healthy, naturally flowing river - so do all the people and nature that rely on it.

© Robin Darius / Felis


#14 Ganges

The Ganges is one of the most revered rivers in the world. It has a vast spiritual and cultural significance, represented by the variety of festivals that celebrate the legends of the river. But the river is mighty for many other reasons. Rising from the Gangotri glacier in the Himalayas, the Ganges River flows for over 2500 km until the Bay of Bengal. Its basin is the 5th largest globally, shared by Nepal, India, and Bangladesh. Home to more than 500 million people, it is the most populated river basin in the world, providing a variety of benefits from water for homes, agriculture and industry to freshwater fisheries for riverside communities. Together with the Brahmaputra river, it forms the world's largest delta, which is amongst the most fertile regions globally. But the Ganges is also among the world's most biodiverse river basins, safeguarding rich aquatic and terrestrial ecosystems and biodiversity, including the iconic Ganges river dolphin and many other rare and endemic species. Nevertheless, excessive water abstraction for agriculture as well as hydropower dams affect water and sediment flows in the river, contributing to the sinking and shrinking of its delta. Reduced freshwater flows also affect the health of the river, impacting people and nature. But at least the threats to the Ganges are starting to be acknowledged and addressed. Governments and civil society organisations are doing their bit to mitigate the threats to the river and ensure the survival of the ecosystems and species it sustains. The Government of India’s Initiatives like Namami Gange, Project Dolphin and WWF's Iconic Free-Flowing Rivers and River Dolphin Rivers, are helping to restore the river's flows and health for the benefit of people and nature.

© WWF / Michel Gunther


#15 Danube

The Danube is the second-longest river in Europe and the world’s most international river, crossing through ten countries and draining the territory of 19  – an area over 800,000 km². It flows for over 2,850km from its headwaters in Germany’s Black Forest Mountains down towards the Black Sea. Home to 83 million people, the basin unifies and sustains a wealth of diverse cultures and traditions. With its outstanding landscapes, it provides multiple ecosystem services, including flood protection, fisheries, agriculture, tourism, and drinking water for more than 20 million people. The basin harbours Europe’s largest natural wetland – its Delta - and exceptional levels of biodiversity, including more than 5,000 species of animals and plants like the white pelican, beavers, and five sturgeon species on the brink of extinction (one species already extinct). The Danube has been drastically altered in the past 150 years: more than 80% of the river has been regulated, its natural floodplains with marshes, meadows and floodplain forests drained or cut from the river. For hydropower generation, flood protection or water supply purposes over 940 dams, ramps/sills built on the Danube basin on rivers with catchments larger than 4000 km2. Rapid economic growth further reduced the basin’s health through gravel extraction, navigation, and pollution from domestic waste, industry, and agriculture. And now climate change poses new threats to Danube’s wildlife and people. But this doesn’t have to continue. WWF works with partners to bring life back to the river through initiatives and larger programmes like the Living Danube Partnership and Living European Rivers which interventions include dam removals, river and floodplain restorations,  Nature-based Solutions, as well as fighting against new deterioration caused by infrastructure projects. The Sturgeon initiative and Life for Danube Sturgeons engage in sturgeon protection measures in Danube countries - this critically endangered migratory fish is an indicator of the river’s continuity and status. 

© Federico Valido


#13 Río Gallegos

Río Gallegos is a 300km long river in the Argentinian province of Santa Cruz. Named in 1520 after one of the pilots of Ferdinand Magellan's expedition, Blasco Gallegos, the river flows from its source in the Andes mountains towards its estuary on the Atlantic Ocean, where the city of Río Gallegos now sits. The capital of Santa Cruz with around 80,000 inhabitants, it's the second-largest city on the Patagonian coast, with an economy based on livestock farming and extensive commercial and port activities. The Gallegos river boasts two important tributaries - the Chico and the Turbio - and its upper course runs through Argentina's most important coal basin. It is one of the rivers with the highest economic value in the region, thanks to the presence of trout, which is popular among fly-fishing tourists. However, trout were introduced in the region, and are now threatening native species. But the basin is still home to incredibly rich biodiversity, including the red fox and the unique Hooded grebe, which uses the estuary as one of its few wintering grounds. It also safeguards a great diversity of native plants, including a dazzling array of flowers, which can be seen on the front of many houses. Río Gallegos' flow of sediments accumulates in the basin's estuary, which sustains numerous salt lakes and marsh vegetation, forming a dynamic system that is crucial for people and nature. Depending on seasonal snow melt, the Río Gallegos is vulnerable to climate change. It also faces a number of other threats, but it's possible to tackle these before it's too late. Indeed, it is not only possible but essential since only a resilient and healthy river can continue to give life to its namesake city and all the people and wildlife that depend on it. 

© Brent Stirton / Getty Images


#12 Sepik

Stretching for over 1100km, the Sepik is Papua New Guinea's longest free-flowing river and one of the most pristine river systems in the Asia Pacific. The Sepik waters run through tropical rainforest and lowland mangroves, sustaining extraordinary biodiversity and over 400,000 people who depend almost entirely on these habitats for their livelihoods. The basin provides them with food, water, transport, and plants and animals that are the basis of the local economy - built on the sale of sago, fish, freshwater prawns, eels, turtles, and the eggs, skins, and meat of crocodiles. The River is the beating heart of diverse communities and cultures, with more than 300 languages spoken in an area the size of France. But as flagged by WWF's 10 Rivers at Risk report, plans to develop the largest mine in the country on one of its major tributaries threatens the future of the Sepik and its people and nature. The gigantic plan includes an open-pit copper mine, a massive tailings dam, and a hydropower dam to power the project. Little of the promised revenue would end up in the Sepik region, while local communities would bear the social and environmental costs. Toxic chemicals would poison the River and surrounding ecosystems, while the hydropower dam would impact the Sepik's natural flow. And there's a high risk of a disaster, as it's an area of high seismic activity and extreme rainfall. But the people of the Sepik River are fighting for their River. In an unprecedented move, chiefs representing 78,000 people joined forces in a campaign to Save The Sepik, publicly calling for the project to be stopped. 

© Wild Wonders of Europe / Dieter Damschen / WWF


#11 Elbe

The Elbe is the fourth-largest river basin in Central and Western Europe. It flows for over 1000km from its source in the Krkonoše (Giant) Mountains of the Czech Republic, crossing through Germany until it spills its waters into the North Sea. The river basin is home to about 25 million people and boasts world-famous cities, including Prague, Berlin, and Hamburg. The Elbe River Landscape is Germany's largest inland UNESCO biosphere reserve and one of the last near-natural river landscapes in Central Europe. Numerous plants and animals are dependent on the Elbe's waters, like the Elbe beaver, fire-bellied toad, and the European sea sturgeon, which is currently being reintroduced. But much of the Elbe has been regulated for navigation and dammed in the Bohemian stretch - the incision of the river bed due to the continued maintenance of the waterway is one of the key problems of the middle Elbe, affecting the river, its floodplains, and their water regime. Poor water quality is also an issue, although it has greatly improved over the last 30 years - in the early 1990s, the Elbe was in some stretches classified "ecologically dead". While the floodplain ecosystems depend on regular floods, the river is infamous for devastating extreme flood events (2002 and 2013), but it is also suffering more regularly from too little water (droughts). Climate change will likely increase the frequency of floods while also increasing the risk of droughts, with adverse impacts on several sectors, including water supply, agriculture, industry, navigation, and recreation. But this doesn't have to happen. WWF’s Nature-based Solutions include initiatives like the Lödderitz dike relocation to enhance the health and resilience of the river basin, including by restoring freshwater habitats by removing dams and making room for the river.

© Day's Edge Productions



Rising in the Rocky Mountains in the United States, this mighty river flows downstream, eventually forming a natural boundary between the US and Mexico. The Rio Grande, known as the Rio Bravo in Mexico, flows to the Gulf of Mexico, despite the many barriers it encounters along the way. It is the heart of the Chihuahuan Desert, one of the three most biodiverse deserts in the world. The Rio Grande/Bravo basin encompasses two global biodiversity hotspots, and it is a vital flyway for migrating birds and butterflies, and nearly half of all the fish species are endemic. It also provides freshwater to over 16 million people on both sides of the border, from indigenous peoples to ranchers and farmers - all depending on the river’s life-giving waters. Contributing billions of dollars to the economies of both countries, the river has been overallocated, overused, and dammed since the late 19th century, primarily due to irrigation for agriculture, followed by domestic use. The river basin health’s also faces growing threats, including climate change, pollution, and invasive species. Added to the complex and fragmented governance, the River nowadays dries up in many stretches – completely near El Paso in what is known as the “Forgotten Reach”- and it was declared one of the ten most water-stressed rivers globally by WRI in 2014. But there’s still hope for the Rio Grande. WWF projects support partners and stakeholders in identifying key conservation needs and solutions via scientific and technical expertise. Initiatives like those focused on improving corporate water stewardship can help mitigate impacts on the river and support restoration of critical flows and habitats.

© Weiyang Dou


#8 Yangtze

The Yangtze River is Asia's longest river and the world's third, flowing for more than 6300km from the Tanggula Mountains in Tibet towards the East China Sea. Its basin is one of the world's most biologically diverse ecoregions due to the climatic, geographical, and geomorphological diversity and complexity of river-lake relations. Known as the "Mother River" in China, the Yangtze is home to 459 million people, approximately one-third of China's total population. Cutting through 11 provinces, the river is central to China's past and future – providing water, food, and livelihoods for thousands of years. It has sustained much of the Chinese economy and social development – just in 2018, the GDP of the Yangtze River Economic Belt reached approximately 40% of the national GDP. The basin also safeguards incredible and ancient biodiversity like the Giant panda, Chinese sturgeon, and the world's only freshwater porpoise, the Yangtze finless porpoise. With over 400 species of fish swimming its waters, the basin has been featured as "the cradle of China's freshwater fishery" and "a treasure trove of fish genes". But the Yangtze is at risk - WWF's 2020 Yangtze Living Index report concluded that the overall health of the basin is declining fast and deteriorating as the river flows from source to sea. Driven by population growth, rapid industrial, agricultural, and fishery development, hydroelectricity development, and navigation, the river faces climate change, alterations to its flow, land-use change, pollution, overfishing, and invasive species. These pressures threaten water supplies and freshwater fisheries that feed millions. The Chinese government is quite aware - it established a 10-year fishing moratorium in January 2021. But as WWF's report shows, more can and should be done to save the Yangtze and all the benefits the "mother" river provides to humans & nature.

© Griffin Shanungu/WWF Zambia


#10 Zambezi

The Zambezi River is the largest in Southern Africa and the fourth largest river system in Africa. Rising in Zambia’s Kalene hills, it flows for over 3,500km towards the Indian Ocean. The eight countries it crosses are home to more than 30 ethnic groups, whose cultural roots are deeply intertwined with the seasonal life of the river. In Zambia, the Kuomboka people celebrate their seasonal movement as the flood waters expand and then recede. Around 40 million people rely on the river’s abundant ecosystem services, including clean water, fish stocks, fertile soils, and flood and erosion control. Tourism alone has a total annual direct value of US$515 million in the basin with people being lured to the river by its incredible biodiversity and natural wonders, particularly the Victoria Falls. The basin is also home to more than 35 protected areas, including part of the world’s largest Transfrontier Conservation Area (KAZA). These habitats safeguard a large number of species, including over 6000 plants, 700 birds, 165 freshwater fish, and 200 mammals from elephants to lechwe, hippos and lions. But the region’s growing population and economic development is driving ever-increasing demand for water, adding to pressures on water resources and ecosystems across the basin. Threats include alterations of natural flow regimes due to hydropower infrastructure; water pollution; unsustainable riverbank cultivation; deforestation of catchment areas and headwaters; invasive species; and overfishing. And climate change will worsen this scenario. But there’s hope to enhance the Zambezi’s health for the benefit of people and nature. Working with partners, WWF is playing an instrumental role in supporting KAZA as well as in developing and implementing the Upper Zambezi Project and the Blue Heart of Africa initiative

© Nicolas Axelrod / Ruom / WWF-Greater Mekong


#7 Mekong

One of the world’s great rivers, the Mekong flows nearly 5,000km from the Tibetan plateau to where its great delta meets the sea. Crossing through Laos, Thailand, Cambodia, and Viet Nam, the Lower Mekong supports the world’s most productive freshwater fisheries. Its fertile delta, nourished by the sediment carried downstream by the river’s natural cycles, is Viet Nam’s rice bowl, producing half of its total rice harvest. The Mekong basin is home to 70 million people who depend on a healthy, free-flowing river for water, irrigation, energy, transportation, and trade. Its waters also sustain thousands of species in one of the most biodiverse regions on Earth, including 89 Critically Endangered river dolphins and over 1000 fish species, including many of the world’s giant fish and the dazzling Siamese tiger perch. But all this life is under threat - hydropower dams and sand mining are stripping the famously muddy river of its sediment. The result: the Mekong delta is sinking and shrinking, putting people’s lands and livelihoods at risk. And Laos plans to build another four large hydropower dams across the main channel, which could slash the sediment supply to just 10% of its natural levels. Coupled with excessive groundwater abstraction and sea-level rise due to climate change, half of the Mekong delta could disappear under the waves by the end of the century. And the River basin also faces deforestation, industrial pollution, and overfishing. But another path is possible, as WWF’s 10 Rivers at Risk report enlightens - renewable alternatives, like solar and wind, are LowCx3 low carbon, low cost, and low conflict with rivers and communities. In 2020, the Cambodian government showed the way by imposing a 10-year moratorium on hydropower dams on Mekong’s mainstream, and encouraging investment in solar power. Keeping it free flowing is the best way to build resilience to climate change.

© Faouzi Maamouri


#6 Sebou

Flowing 500km from Morocco's Middle Atlas mountains to the Atlantic Ocean, the Sebou River is the largest North African river by volume. It is the main river of the Sebou basin, which is a water tower for Morocco. Although it represents only 6% of the country's land area, the basin is of crucial socio-economic importance – its 40,000 km2 is home to nearly 20% of the population. The livelihoods of 6.2 million depend on the basin, and its agricultural and industrial outcomes significantly contribute to the national economy. Morocco's most fertile region is located at Sebou rivers' mouth, being the country's most important agricultural region. The Sebou basin also has more than 10 large dams, one of which is the second largest dam in Africa. However, many of these infrastructure developments have negatively impacted the basin's remarkable ecosystems, which contain 39 important wetlands, 7 of which are Ramsar sites; 2 national parks; and 17 biological and ecological zones of interest. The basin also sustains many migratory birds and other rare and endangered endemic animal and plant species. But the Sebou and all the benefits it provides are threatened by: groundwater resources' overexploitation for agriculture; pollution from solid waste and industrial activities; hunting and poaching of birds and their eggs; and overexploitation of forests around lakes and overgrazing. Currently, only 25% of the basin drainage is covered with natural vegetation. Aiming to maintain and restore the quantity and quality of the Sebou's surface waters (lakes, streams, and wetlands) and recharge the aquifer, WWF launched the Sebou Water Fund in 2018. Water Funds are a sustainable financing mechanism based on payment for Ecosystem Services, where funds provided by the water beneficiaries are invested in improved watershed management.

© Jaime Rojo / WWF-US


#5 Paraguay

The Paraguay River is a major waterway in south-central South America. It meanders 2,600 km from its source in Brazil through Bolivia and Paraguay before joining the Paraná River and flowing into Argentina. The river is responsible for balancing an entire ecosystem, as it feeds the largest tropical wetland on the planet – the Pantanal. One of the most important regions in the world in terms of services provided to humanity, Pantanal’s annual cycles of floods and droughts dictate the lives of thousands of species. It sustains more than 10 million people living in the region and provides water to cities downstream. It also supports more than 4,000 species, including the threatened jaguar, the world’s largest concentration of caimans, and 23 migratory fish species critical to local fisheries. All this depends on the connectivity and natural flow of the Paraguay River, but plans for more hydropower projects threaten Pantanal’s lifeblood. And there are already over 50 plants in the basin. Most of them are small, but together they can have a big impact - the Brazilian Pantanal has lost 74% of its surface water over the past 30 years, partly due to dams infrastructure. Fishers reported that fish have disappeared as migratory routes have been cut. The region also faces agriculture expansion, unsustainable ranching, and engineering work for navigation. Unsurprisingly, wildfires have ravaged the drying Pantanal recently. WWF’s actions to protect the region include the Jornada da Água (Water’s Journey), the Pact in defense of the headwaters of Pantanal, and the Iconic Free Flowing Rivers initiative. But an additional 80 hydropower dams are still planned, closing off 11,000-12,000km of free-flowing river channels. But there is another path. Alternative renewables, like solar and wind, are LowCx3 - low carbon, low cost, and low conflict with rivers and communities - and could produce enough energy for the region while creating more jobs without destroying the rivers that give Pantanal life.

© WWF-Russia-E.Agryzkov


#4 Amu Darya

The Amu Darya is a major river in Central Asia, connecting Afghanistan, Tajikistan, Uzbekistan, and Turkmenistan. Formed by the merger of the Vakhsh and Panj rivers in the Tigrovaya Balka Nature Reserve, it flows down 2500km into the Aral Sea. People's livelihoods in the river basin (about 55 million in 2011) and the Aral Sea Basin depend on its waters, mainly allocated to agriculture – the region's key economic sector- hydropower generation, and industrial, domestic drinking needs. The river valley is composed of riparian forests known as Tugai – a floodplain jungle specific to Central Asia and a keystone aquatic ecosystem that used to be home to the extinct Caspian tiger. Together with the Syr Darya River, these floodplains harbour a remarkable amount of biomass and rich biodiversity, including more than 250 species of birds. But the Amu Darya is at risk. System of dams and canals for irrigation prevent natural floods and cause degradation of still existing riparian ecosystems. In the 20th century, agricultural fields replaced about 90% of the Tugai, and unsustainable irrigation used up to 95% of the river's water flow. Due to evaporation when the river flows through the Kyzylkum desert, the basin faces significant losses before reaching the Aral Sea. The Amu Darya is also under pressure from climate change - glaciers in the Himalayan region feed the river, where water flows are being reduced. WWF conservation efforts include the "Integrated river basin management and nature protection in the Tigrovaja Balka reserve" and the Bukhara deer conservation and restoration projects. WWF Russia also focuses on the critically endangered sturgeons in the Amu Darya and Tumnin rivers, together with our Sturgeon Initiative. In the long term, all the riparian countries must take action and use water efficiently, starting with developing the Amu Darya River Basin plan.

© W. Retter



The Isel is the last free-flowing glacial river in the European Alps. Its clear, cold waters flow almost 60km through gorges, gravel banks, and floodplain forests of Austria's East Tyrol region. Still in a near-natural state, it harbours many threatened species like the German tamarisk (Myricaria germanica) and draws tourists that power the local economy. But the future of the Isel is at risk. For years, developers have been trying to build new hydropower on the river and its tributaries, although over 1,000 hydropower plants are already in operation across Tyrol. And authorities appear unwilling to stop them, as six plants are planned, in the approval process, or under construction in the basin. These dams will alter the natural flow of water and sediment, threatening these free-flowing rivers' benefits. WWF's 10 Rivers at Risk report shows that these plants will produce negligible amounts of power at far from little cost, plus the high cost to nature and people – like the €30 million power plant which will provide electricity to only 1.100 local people, besides getting the municipality into debt to finance the project located at a site prone to landslides, floods, and avalanches. WWF and 43 groups, including prominent scientific voices, are calling for an end to all new hydropower development in the Isel and across the region. Renewable alternatives (e.g., solar and wind) offer a better path as they are LowCx3 - low carbon, low cost, and low conflict with rivers and communities. This way, authorities can protect one of Europe's last natural river systems to benefit nature and future generations. 

© WWF / Folke Wulf


#3 Kavango

The Kavango River (a.k.a Cubango in Angola and Okavango in Botswana) originates in Angola and flows for around 1200km to the south, where it joins the Cuito River. Together, they enter the flat basin of the Kalahari Desert in Botswana and spill into the Okavango Delta – the world’s largest inland delta. Regarded as one of Africa’s Seven Natural Wonders, this delta creates a dynamic wilderness unlike anything else on Earth. Its beautiful floodplains are rich in biodiversity and home to some of the most endangered large mammals in the world. A thriving nature-based tourism industry is key to the local and national economy, while freshwater fishes are crucial to local communities' food security and livelihoods. But the river that feeds the delta is at risk. The largest threat is the proposed hydropower dam at Mucundi in Angola, which would fragment the river and alter the natural flow of water, sediments, and nutrients that keep the delta healthy. The Kavango is already under pressure from the growing demand for water for agriculture and the impacts of climate change - a disruption of this free-flowing river would further undermine its resilience, and the delta would eventually succumb. But there are alternatives. Investments in renewables such as solar and wind promise a faster path to power generation and are LowCx3 energy sources - low carbon, low cost, and low conflict with rivers and communities. Sustainable development of the region is possible, but only by safeguarding the river that flows through its heart. The local inhabitants of Angola call Kavango's source waters "Fonte da Vida"- the Source of Life. By protecting these countries’ life source, we can power a better longer-term future for their people and nature. 

© Zig Koch / WWF-Brazil


#1 Tapajós

Brazil's Tapajós River is one of the largest, free-flowing tributaries of the Amazon, flowing for over 2000km through habitats ranging from the cerrado savanna to rainforests. It is also one of the few fast-flowing, clearwater rivers in the region, boasting extraordinarily rich biodiversity like the endangered river dolphin Tucuxi. Indigenous people and local communities also depend on Tapajós' natural flows and flood pulses – it supports fisheries, fertilizes fields, and provides clean water, sustaining livelihoods and cultures. But all these benefits are under threat, especially from hydropower dams. Regarded as one of the best remaining hydropower generation opportunities, there are 42 dams planned in the Tapajós River. WWF's 10 Rivers at Risk report  states that the region will suffer disastrous environmental and social consequences if these dams are built, such as flooding around 2,000km2 of Indigenous territories by reservoirs. It would also promote deforestation, which generates greenhouse gas emissions - hindering efforts to tackle the climate crisis. Thanks to the indigenous Munduruku tribe, who've fought years of court battles to protect their lands, the largest proposed dam at São Luiz do Tapajós was cancelled in 2016. But there are still many on the drawing board. Instead of pursuing 20th-century infrastructure solutions, Brazil should reassess the best energy mix by factoring in the plunging price of renewable alternatives, like solar and wind, and the full impact of these dams on communities, wildlife, and the climate. The hydropower plans on the Tapajós should be replaced by renewable energy that is LowCx3: low carbon, low cost, and low conflict with communities and rivers. 

© Zig Koch / WWF-Brazil

© Zig Koch / WWF-Brazil

© Zig Koch / WWF-Brazil