It is becoming increasingly clear that access to water is going to be amongst the largest problems we will face over the next 50 years, and that the effects will be felt worldwide.

Our water supply affects everything from our drinking water and food production through to our ability to respond to wildfires (more on that later). Outlined below are some of the scarier components of this complex challenge, in balance with some more positive news, because all is not lost and it is optimism that keeps us going.

In  May 2017, Cape town suffered a severe drought, and planned to indefinitely cut off its water supply, leaving 4 million people without access to water beyond a centralised rationing system. Referred to as ‘Day Zero’, it was the first major city in the world to suffer this phenomenon, but it is becoming more and more likely across the rest of the world with cities like Sao Paulo, Melbourne, London, Jakarta, Beijing, Istanbul, Tokyo, Bangalore, Barcelona and Mexico City on the risk list for their own Day Zero over the next few decades.

Over the past 20 years, floods have increased by 134% and droughts by 29% (1). Both phenomena are expected to increase in frequency and severity, and both have huge effects on our clean water supply. In October last year, Pakistan suffered the worst flooding it has ever seen, primarily caused by rainfall and glacier melt following a severe heatwave and drought. One would imagine that rainfall would be welcome after a drought, however, when ground is extremely hard and dry rainfall cannot easily be absorbed, as illustrated in this video by Dr Rob Thompson from the University of Reading.

Combining the increase in extreme weather events like drought and rainfall with increasing demand on our water supplies can have devastating effects on our access to fresh water and our livelihoods. Over one in four people live in countries affected by water stress (1), and by 2050, more than 5 billion people may suffer from water scarcity, threatening 45% of the world’s economy.(1)(2) It is an issue that will inevitably affect all of us.

The problem lies not just with our usage, but with our increasing usage.  With more uptake of Westernised diets, the demand for meat and animal products increases adding further pressure to our water supplies.(3)

For context, here are a few examples of water use in products regularly consumed within developed countries. A cup of coffee costs 130 litres of water. A single cotton T shirt costs 2500 litres and a single kilogram of beef takes 15 thousand litres of water to produce. 70% of our water goes to agriculture and yet we don’t see that reflected in the cost of our food products because water has a price cap.

Because of this, 95% of our global irrigated farmland uses ‘flood irrigation’, where fields are flooded for periods of time. This water comes straight from our mains, is not collected from rainfall or runoff and is potable water.

Water is the only product in existence that is not driven by supply and demand. It is required as a basic human need, and yet it is one of the scarcest resources compared to demand. Due to our right to water it remains cheap, which means we remain wasteful. Mexico City takes 50% of its water from an aquifer underneath the city, despite having more rainfall annually than London. (4) and 42% of Mexico City’s water is lost through its leaky central plumbing network. Record periods of drought are evident in Las Vegas. 240 consecutive days without rainfall were recorded in the year 2020, and Las Vegas itself suspect to some of the most egregious water usage, with an average household usage of 222 gallons (1000L) per day in this city built in the middle of the Mojave Desert. The effects of this consumption are felt downriver. Most of Las Vegas’ water supply is drawn from the Colorado River which snakes on through Nevada and into California – a region where we have seen a terrifying rise in wildfire caused by soaring temperatures and extended drought (5).

These droughts are due partially to weather events and in part to excessive water usage upstream, leading to depletion of the resource where it is needed. Almost 70% of California is considered to be in ‘extreme to exceptional drought’ (6) and yet 80% of the world’s supply of almonds – a thirsty crop –  is grown in California, taking annual water supplies 35 times greater than all of the homes in San Francisco. (7)

But there’s hope.  We must put in place strategies now that will support resilience in the future. Industrial and behavioural changes can make a huge impact. This is exemplified by Capetown’s Day Zero countdown clock, which was paused indefinitely after the city’s water consumption halved through behavioural changes.

Changing the method of costing water can change the way that we consume; for example, any consumption above a baseline of 60 litres per person per could be charged on a sliding scale. We must also consider the energy use in processing water. By adopting methods of collecting and repurposing used water and rainfall, we can reduce our carbon emissions.

What changes could we make as individuals, today? Some research shows that we should use dishwashers rather than handwashing our tableware, with up to 57 litres of water saved per full load. We can shower for less time and wash clothes less frequently. We can collect rainwater and use it for growing plants. We can embrace a more plant-based diet. Making a start today, we’ll form better habits for water supply resilience in the future.

References

1. Avoiding Day Zero, a global water crisis. Daro Soto-Abril and Johannes Cullmann (https://www.openaccessgovernment.org/global-water-crisis/124467/)
2. 2 FAO and UN-Water. 2021. Progress on Level of Water Stress. Global status and acceleration needs for SDG Indicator 6.4.2, 2021. Rome. The level of water stress is defined as the ratio between total freshwater withdrawals by all economic activities and total available freshwater resources, after considering environmental flow requirements. Environmental flow requirements are essential to maintaining ecosystem health and resilience. When an area has a level of water stress of 25% or more it is said to be ‘water-stressed’.
3. https://www.visualcapitalist.com/visualizing-rapidly-changing-global-diet/
4. The world water crisis, explained, Netflix,
5. https://www.latimes.com/projects/california-fires-damage-climate-change-analysis/
6. https://www.theguardian.com/us-news/2015/jun/26/california-wildfires-water-shortage-drought
7. https://www.motherjones.com/environment/2015/01/almonds-nuts-crazy-stats-charts/