40 Fun Facts About World Water Day

Which South African city counted down to 'Day Zero' in 2018, when its taps were due to be shut off?

Cape Town never reached Day Zero: residents cut their daily water use by more than half, and strong rains from June 2018 refilled the dams.

Which meat has the largest water footprint, averaging about 15,400 litres for every kilogram produced?

Beef takes more than three times as much water as the same weight of chicken. Across livestock farming, about 98 percent of the water goes into growing the animals' feed.

Which disease did physician John Snow trace to a contaminated water pump on London's Broad Street in 1854?

Cholera was widely blamed on bad air, but Snow traced the deaths to the pump, and parish officials took off its handle the day after he made his case to them.

In Chile's Atacama Desert, large vertical mesh nets are strung up to harvest water from which natural source?

Fog droplets cling to the mesh and run down into a trough below. Namib Desert beetles pull off the same trick, drinking the water that condenses on their wings.

World Water Day falls exactly one month before Earth Day, on which date each year?

22 March was fixed by a United Nations vote in December 1992, and the first World Water Day was observed the following year.

Which Central Asian lake shrank to a tenth of its size after Soviet projects diverted the rivers feeding it?

The Aral Sea lost the Amu Darya and Syr Darya to desert fields of cotton and rice. Its dried-out eastern basin is now called the Aralkum Desert.

Which Hollywood actor co-founded the charity Water.org with Gary White to offer families loans for household taps?

Matt Damon has fronted the charity's adverts, including a Super Bowl spot. Its small loans let a family install a tap instead of paying a vendor or walking to fetch water.

Which sector takes about 70 percent of all the freshwater that people withdraw from rivers, lakes and aquifers?

Agriculture takes 69 percent of global withdrawals in the UN food agency's figures, against 19 percent for industry and 12 percent for towns and cities.

World Water Day 2025 called for the preservation of which shrinking natural stores of freshwater?

Glaciers were chosen because their meltwater supplies drinking water, farms, industry and clean energy far downstream.

Which Michigan city's 2014 switch to a local river supply let lead leach from ageing pipes into tap water?

Flint's new supply was never treated with corrosion inhibitors, so it ate into old lead pipes and exposed around 100,000 residents.

Which United Nations body passed the December 1992 resolution that created World Water Day?

The General Assembly named it the World Day for Water in resolution 47/193, and the first one was held just three months later.

Which country hosted the 1992 Earth Summit, where a yearly day devoted to fresh water was first proposed?

Brazil staged the summit in Rio de Janeiro, where 108 heads of state and government turned up. The UN made the day official that December.

Which action plan adopted at the 1992 Earth Summit first proposed an international day for fresh water?

Agenda 21 is a non-binding UN plan for sustainable development, and its number points to the 21st century it was written for.

Which hidden resource did World Water Day 2022 spotlight under the theme 'Making the Invisible Visible'?

Groundwater makes up about 99 percent of the world's liquid fresh water, yet it is easy to overlook because it lies out of sight beneath our feet.

Which bird, hero of an old story about carrying drops to a great fire, fronted World Water Day 2023?

Hummingbird was the emblem of the 2023 campaign, Be the Change, which asked people to do what they could about their own water use, however small.

Which Paris-based UN agency publishes the World Water Development Report, launched on World Water Day each year?

UNESCO produces the report through its World Water Assessment Programme, and each edition tackles the same theme as that year's campaign.

Which of the UN's Sustainable Development Goals promises clean water and sanitation for all by 2030?

SDG 6 is one of 17 global goals and has eight targets of its own. SDG 14, which sounds similar, covers life in the oceans instead.

Which UN observance on 19 November, also convened by UN-Water, draws attention to the global sanitation crisis?

World Toilet Day was begun in 2001 by a campaign group, the World Toilet Organization, and became an official UN day in 2013.

Which Nordic capital hosts World Water Week each summer and awards a prize nicknamed the Nobel of water?

Stockholm's prize is presented by Sweden's king, its patron, during the week-long conference.

Which Central Asian country co-hosted the UN 2023 Water Conference in New York alongside the Netherlands?

Tajikistan shared the chair of the first UN water conference in a generation; the previous one had met back in 1977.

Which Bolivian city erupted in a 'Water War' in 2000 after its privatised supply sharply raised bills?

Cochabamba's protests forced the government to reverse the privatisation within months. The supply had been handed to a venture involving the US firm Bechtel.

Which country built the Renaissance Dam on the Blue Nile, alarming Egypt and Sudan further downstream?

Ethiopia's dam is the largest hydroelectric plant in Africa, built to ease the country's acute power shortage and to sell electricity to its neighbours.

Which river system did India and Pakistan agree to divide in a 1960 treaty brokered by the World Bank?

The Indus and two of its tributaries went to Pakistan and three eastern rivers to India, in a deal signed in Karachi by Nehru and Ayub Khan.

Which river flows through four national capitals, including Vienna and Budapest, more than any other in the world?

The Danube also passes Bratislava and Belgrade, and its basin drains parts of 19 countries on the way to the Black Sea.

Which US river, held back by the Hoover Dam at Lake Mead, has rarely reached the sea since the 1960s?

The Colorado is used so heavily by farms and cities that its final stretch is usually dry. A planned release in 2014 let it touch the ocean for the first time in 16 years.

Which vast aquifer beneath the US Great Plains, spanning eight states, would need over 6,000 years to refill naturally?

The Ogallala yields about 30 percent of the well water pumped onto crops in the United States, and irrigation is draining it far faster than rain can refill it.

Which North African country's 'Great Man-Made River' pipes fossil water from under the Sahara to its coastal cities?

Libya's network supplies about 70 percent of the country's fresh water, and Muammar Gaddafi called it the Eighth Wonder of the World.

Which South Asian country's arsenic-tainted drinking wells caused one of the largest mass poisonings in history?

Bangladesh had sunk millions of tube wells to give people a safe alternative to dirty surface water, but the wells were not tested for arsenic at the time.

Which water-scarce island country purifies its sewage into 'NEWater', used mostly by industry rather than homes?

Singapore began studying recycling in the 1970s to cut its reliance on water piped in from Malaysia, long a sore point between the two.

Which continent holds more than half of all the fresh water on Earth, despite counting as a desert?

Antarctica's ice sheet covers 98 percent of the continent and is more than 2 km thick on average, yet so little snow falls there that it ranks as a desert.

Which chemical, first added continuously to a US supply at Jersey City in 1908, is used to disinfect tap water?

Chlorine kills the germs behind typhoid and dysentery. Maidstone in England had become the first town to treat its entire supply with it in 1897.

Which mineral did Grand Rapids, Michigan, begin adding to its tap water in 1945 in a trial to prevent tooth decay?

Fluoride cut cavities so clearly in the trial that the United States became the first country to treat its public water this way on a wide scale.

Which 1858 London crisis, caused by sewage in the Thames, led to Joseph Bazalgette's vast network of sewers?

The Great Stink struck in a hot summer, and Bazalgette's sewers gave London its Victoria, Chelsea and Albert Embankments, which they run beneath.

Desalination plants that turn seawater into fresh water leave behind which concentrated by-product?

Brine is so salty that plants can dilute it with a power station's cooling water before returning it to the ocean.

Which disease, caught from tiny crustaceans in drinking water, fell from 3.5 million yearly cases to a handful?

Guinea worm has no vaccine or drug treatment. Cloth filters and keeping infected limbs out of ponds have brought it close to eradication.

Which water-saving farming method, developed in Israel by Simcha Blass, feeds plants through small plastic emitters?

Drip irrigation became a business when Blass and Kibbutz Hatzerim founded Netafim and patented the first practical emitter.

Which name is given to used water from sinks, showers and washing machines that can be recycled for gardens?

Greywater carries far fewer germs than sewage, so it is safer to handle and easier to treat on site for watering plants.

Which ancient people built the three-tiered Pont du Gard to carry water 50 km to the city of Nîmes?

The Romans' bridge still stands almost 49 metres high in southern France, and its channel once fed the fountains, baths and homes of the town.

Which Latin American capital, built on a drained lake bed, is sinking as water is pumped from beneath it?

Mexico City rests on the soft clay of the drained Lake Texcoco, and parts of it have sunk by as much as 9 metres since 1900.

World Wetlands Day on 2 February marks a 1971 treaty signed in which Iranian city that gave the treaty its name?

Ramsar hosted the signing, so the marshes, deltas and lakes that countries protect under the treaty are known as Ramsar sites.