Freshwater and clean/safe drinking water are going to become extremely valuable resources in the future as population increases.
In this guide, we outline how much freshwater & drinking water is left on earth, and give an indication of when we might run out.
Summary – How Much Freshwater (& Drinking Water) Is Left On Earth, & When Will We Run Out?
The answer to that question is location specific.
Not only does water have to be safe and clean to drink and use (not contaminated or polluted), but it has to be accessible in the city or area where people need it (there’s far less value in freshwater concentrated in areas of the world where there are less people living there that can actually use it).
Each city, town or region needs a short term and long term strategy to managing their water supply and water withdrawal/demand rates. This strategy should be specific to the capabilities and challenges that that area faces with their freshwater and drinking water supply. Population growth (heavily impacts demand), water supply capacity, and how the water supply will be sustainably replenished are huge considerations.
This takes a multi level approach and action (or change sin behavior) by water suppliers, government, key decision makers, and the agricultural, industrial/commercial and residential sectors (who actually use the water).
How Much Freshwater & Drinking Water Is Left On Earth?
There’s a lot of water on earth (if you include the ocean), but a very small % of that water is freshwater:
- About 2-3% percent of the planet’s water is fresh, but 1.6 percent (around 70%) of the planet’s fresh water is locked up in the polar ice caps, snowfields and glaciers
- 0.36 percent of freshwater is found underground in aquifers and wells (also called groundwater)
- Only about 0.036 percent of the planet’s total water supply is found in lakes and rivers
When Will We Run Out Of Freshwater & Drinking Water?
It depends, because water supply and whether a particular place will run out of water is location specific i.e. each city, town and region has different water supply capacities, access challenges, and factors that impact that supply.
Not only is quantity of water important, but so is quality and actually being able to access the water close to the place where you need – some water is contaminated/polluted, and freshwater is not evenly distributed around the world in areas where people live and need access to it (this can be a big problem in heavily populated areas). Majority of the world’s freshwater is actually concentrated in only about six or so countries.
If we take Cape Town for example, they experienced a water shortage situation which hit it’s worst from about 2017 to 2018. Population increase over a number of years (and greater demand on water supplies), and a severe drought (which meant lack of rainfall) were some of the main causes.
Some parts of the world have been without drinking water and freshwater for years – and this leads to severe problems across the whole of society. This can be due to water scarcity problems, or other factors like lack of money to build water supply infrastructure – or a combination.
To get an idea of when a city will run out of water you might consider the following (information can be obtained off water supplier or government websites):
- Look at current clean/safe water supply levels
- Look at maximum water supply capacity
- Look at how the water supply levels have been trending over the last few years and last few decades – is it consistent decreasing?
- Look at the demand on that water supply (the usage rate) by the residential, industrial/commercial and agricultural sectors – should be given as an amount per day
- Look at the factors that determine whether the water supply levels stay at a suitable level to meet demand
- Look at projections going forward for that area with water supply variables and population growth factored in. Do re-fill rates outstrip withdrawal rates?
These things should give you an idea of whether an area will run out of water, and by when.
But, the main indicators are total supply, replenishment rates, and withdrawal rates from that supply.
As an example, the city of Melbourne in Australia provides water storage and usage data at https://www.melbournewater.com.au/water/water-storage-and-use#/ws/freq/daily/type/storage. They also provide data on rainfall catchment and flow into water storages.
There’s a very long list of variables that can impact present and future water supply and withdrawal in a particular location – with rainfall and changes in weather patterns (possibly due to climate change) being a few of them (but there’s many more).
Things cities and regions might do to prevent themselves running out of freshwater are establish and impose sustainable daily water usage rates, and augment water supply to increase capacity (with population growth in mind). But, there’s many strategies and actions that can be implemented beyond just these core strategies.
Something that is very clear is that all cities need to start getting serious about using their water supplies sustainably, and be aware of exactly what action that is going to take for the area they live in.
Barring a huge breakthrough like being able to turn saltwater into freshwater in a cheap and efficient way that uses renewable and clean energy, water restrictions (decreasing daily water usage rates), water efficiency and looking for effective ways to increase water supply capacity are going to be important.
Which Cities & Places Are Most Likely To Run Out Of Freshwater In The Future?
- New Delhi and Hyderabad in India, Beijing, among other Chinese cities, Jakarta, Singapore and Sydney in the Asia-Pacific region, Brussels and Rome in Europe, along with San Francisco and the Manhattan area in the U.S. are some of those with relatively high water risks
- Sao Paulo, Bangalore, Beijing, Cairo, Jakarta, Moscow, Istanbul, Mexico City, London, Tokyo and Miami are also cities identified as being at higher risk of running out of water in the future
Although, it should be noted some of these cities have been working on addressing that water risk to various extents.