Queues at public water taps could become normal. What can we do to avoid them?
PRIMER
Last month saw the hottest start to June on record, the arrival of increasingly normal hosepipe bans and water infrastructure targeted in the Russia-Ukraine war. As things heat up, aquifers shrivel – and London’s 90-day-supply of water means the city is never far from having its taps run dry. That’s Day Zero: a benchmark that several cities around the world have come alarmingly close to – or, in some cases, already reached – in the last decade. We spoke to Priti Parikh, professor of infrastructure engineering and international development at University College London, about the looming threat of Day Zero and how household tricks and national innovations offer promising solutions.
WHAT IS DAY ZERO?
Day Zero is the countdown to when a city or location runs out of water. The term was coined initially in South Africa, in Cape Town, where there was a water crisis in 2018. The city, which had four million people, was at risk of being left without water – and this led to a series of campaigns and restrictions on water use. In January 2018, for example, Cape Town declared water restrictions of 87 litres (l) per person per day, and later decreased it to 50l per day. The actual Day Zero was estimated to happen in April or May – there were complicated calculations around the exact date because the city is dependent on water from six dams.
But luckily it rained and Day Zero didn’t happen. It’s quite striking that a city of four million residents was left at the mercy of rains.
WHAT WOULD DAY ZERO LOOK LIKE?
Chennai, the sixth largest city in India, has between six to ten million residents and reached Day Zero in 2019. As they came closer to Day Zero, there were restrictions on water supply to houses, which meant that people had to take buckets and queue up for water collection. They had to purchase water from private vendors at very high costs. It had a big impact on local businesses and hospitals (to provide vital healthcare services, you need access to water). Once again, the city was saved by rain, but it was a very serious situation affecting mental health and wellbeing, the economics of the city, but also the social fabric of Chennai.
WHAT DOES IT TAKE FOR THIS TO HAPPEN?
As human beings, we have overexploited environmental resources on our planet. In places where we rely on groundwater, we keep on pumping and extracting it out, and this happens over a period of years.
