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      1. Rivers, lakes & wetlands

Threats to Rivers, Lakes & Wetlands

Problems for the global freshwater situation

Freshwater is the single most essential good for our well-being. Like a giant engine working day and night, the water cycle and inherent ecosystems are the life support of the planet.

A recent WWF study estimates that the economic values of wetlands alone are at least $70 billion USD annually.
Children playing in heavily polluted river in the slums near Bombay, India.

Children playing in heavily polluted river in the slums near Bombay, India.

© WWF-Canon / Mauri RAUTKARI

Less than 1% of the world's water is readily available for direct human uses

These uses include agriculture and industry, drinking and domestic purposes, and energy generation and transport. Increasing competition for water among such uses is degrading the very natural resources on which we all depend.

According to United Nations agencies, one-third of the world's population live in countries that are experiencing moderate to high water stress

More than one billion people worldwide do not have access to clean freshwater. Three billion do not have adequate sanitation services and the annual death toll from water-borne diseases is estimated at more than three million.


Pollution from towns and cities, industry and agriculture directly affect water supplies for people and freshwater ecosystems

The collapse of a tailing lagoon at a gold mine near Baia Mare in Romania washed 100,000 m3 of waste water containing cyanides and heavy metals into the Danube river basin, killing fish life and disrupting public water supplies.

Diversion of water for agriculture and industry is destroying freshwater lakes and rivers

In just 30 years, the Aral Sea - formerly the fourth largest lake in the world and a major fishery - has shrunk to less than half of its size, and has become as salty as the ocean. The diversion of irrigation water for agriculture and for power generation, led to severely reduced inflows, leaving an area of almost four million hectares of polluted soils and caused widespread economic losses and human suffering.



Projections of trends into the future do not brighten the picture

Currently, 54% of accessible runoff is appropriated by humans. By the year 2025, two-thirds of the world's population could be facing serious problems with water availability. Predictions regarding freshwater biodiversity impacts over that time-frame vary from the disastrous to the apocalyptic.

Climate change is compounding these effects through increased frequency of extreme weather events.
The Yangtze River is one of the world's rivers showing a decline in freshwater fish stocks.

Rivers in decline

The alteration and damming of river systems for industrial and domestic use,
irrigation, and hydroelectric power have fragmented more than half of the world’s large river systems (LPR 2006). A WWF study shows that only 64 of the world’s 177 large rivers (1,000km and longer) remain free-flowing, unimpeded by dams or other barriers, whilst only 21 rivers longer than 1,000 km retain a direct connection with the sea.
» More on rivers in decline and the threats they are facing
A flood retention polder in Dongting Lake

Floods and droughts claim lives and cripple economies

The UN warns that the number of people worldwide vulnerable to devastating floods is expected to rise to at least two billion by 2050 - particularly in Asia - due to climate change, deforestation, rising sea levels and population growth in flood-prone lands.

Flooding and drought, often brought on by poor management of river basins, claim thousands of lives and cause billions of dollars of damage to economies and communities. Dams and river navigation works have dramatically altered the amount, timing, quality, sediment content and temperature of flows in most major rivers, wreaking havoc on their natural functions.
» More on uncontrolled floods as a result of mismanaged rivers
A representative selection of freshwater species populations (except freshwater birds) have declined on an average by about 50% between 1970 and 2003.

Freshwater species are disappearing

Scientists generally acknowledge that species dependent on freshwater ecosystems are the world’s most endangered group of plants and animals.
More than 20% of the world’s 10,000 freshwater species have become extinct, threatened or endangered in recent decades (CBD2005). Freshwater environments tend to have the highest proportion of species threatened with extinction (MA 2005).
According to the WWF Living Planet Report 2006, the analysed 344 representative tropical and temperate freshwater species populations declined by about 30% overall between 1970 and 2003. Freshwater birds appear to have relatively stabilised while other freshwater species have declined on an average by about 50%.
» More on the freshwater species loss

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