Florida’s algal blooms

Housing and agriculture development has disrupted the natural flow of the Everglades waterways in Florida, causing toxic algal blooms. More than half of the original Everglades has been destroyed for industrial and urban development, which has involved draining waterways and creating canals to divert water. In September the US approved a $2bn package to restore natural water flow.

Karnataka water riots

A woman washes clothes in the Cauvery River in the Indian state of Karnataka. One man died and buildings across Bangalore were torched during a day long riot following a decision this month by Karnataka’s supreme court to release a greater share of the river into next door state Tamil Nadu. Drought in both states has seen farmer suicides spike. As well as population growth and extreme weather, a drop in water availability has been blamed on inefficient use of resources by agriculture and industry, including a switch to more water intensive crops such as sugar.

Russia’s “blood river”

Bright red polluted water on the bank of the river Daldykan near the Russian city of Norilsk in the far north of Siberia. On 7 September, Russia’s environment ministry ordered a probe into the pollution which it said was possibly caused by “a breakage in a slurry pipe at a Norilsk Nickel plant”. The company has denied an industrial spill.

Extreme pollution in India’s Yamuna River

An Indian man bathes in the polluted waters of the river Yamuna in New Delhi, a tributary of the River Ganges. The Yamuna has become one of the dirtiest rivers in the world. Around 58% of the city’s waste is dumped into it, as is chemical waste from factories producing leather goods, dyes and other products. Expensive wastewater treatments have been implemented and city authorities have been experimenting with nature reserves along the Yamuna floodplain. But pollution levels remain incredibly high.

Citarum River - Indonesia

The effects of domestic and industrial waste from factories along Indonesia’s Citarum River prompted environmental groups Green Cross of Switzerland and the Blacksmith Institute to name it as one of the world’s 10 most polluted places. More than 35 million people depend on the river for their lives and livelihoods. The hundreds of textile factories along its banks have leached lead, mercury and other chemicals into its waters. In the last few decades more than 60% of fish species living in the river have been wiped out.

Dams and droughts in the Mekong

A farmer carries pots loaded with water for watering her vegetable crops outside Phnom Penh, Cambodia. Much of south-east Asia is suffering record drought and tens of millions of people are affected by the low level of the Mekong, a river system that flows into Laos, Thailand, Cambodia and Vietnam. Eleven dams are proposed along the lower Mekong with the aim of boosting the region’s economy through hydropower. However, an April 2016 report by the Mekong River Commission predicted the dams would cause “adverse effects” to the environment and economy.

Brazil’s environmental catastrophe

The collapse of a tailings dam at an iron-ore mine in south-east Brazil in November 2015 has been called Brazil’s worst environmental catastrophe. The disaster, which saw waste water flood into the River Doce, killed 19 people, wiped out one town and damaged many others. It also polluted the river, threatening the health and livelihoods of 1.6 million people who live along it. BHP Billiton and Vale, owners of the mine, face a $43.5bn claim from Brazilian prosecutors over the damage.

Contaminated wastewater in the Animas

People kayak in the Animas River near Durango, Colorado. In August 2015, Environmental Protection Agency workers accidentally released 3m gallons of contaminated wastewater, with high concentrations of arsenic, lead and other heavy metals, as they inspected the abandoned Gold King Mine. The waste flowed into the Animus and San Juan Rivers leading Colorado and New Mexico to make disaster declarations for stretches of the river.

Murray-Darling controversies

The Murray-Darling basin covers around 1.06m square km and runs through Australia’s most important agricultural region which produces fruit, vegetables, dairy products, wheat and livestock - all of which require water. The river has become extremely contentious as the demands of agriculture and industry are pitched against environmental concerns exacerbated by a decade-long drought. The 2012 Murray-Darling basin plan aimed to solve the issue, maintaining an “environmentally sustainable” water level by buying back water allocations from farmers

Threats to the Yangtze

Flooding in the Yangtze River basin. The Yangtze is the longest river in Asia and nearly one third of China’s population lives near its banks and relies on its water. However the river faces huge pollution challenges from China’s rapid industrialisation, agricultural run off domestic waste and shipping discharge as well as huge hydropower developments, most significantly the Three Gorges Dam.