10/10/2013 10:13 am ET Updated Jan 23, 2014

Living on Four Liters of Water

Four liters of water. It sounds a fair amount. So just how challenging can it to be to survive on this amount for a day? It's a challenge almost 1 billion face on a daily basis -- with no choice in the matter.

The innovative 4Liters project run by water NGO Dig Deep is asking those of us who do have a choice to choose to live like nearly 1 billion do. It's an act of solidarity, but more than this, it's a tool of education -- it teaches us just how much water we consume in the global North and just how little we value this precious resource which so many lack access to.

I took this challenge on for one day. And that was more than enough for someone already aware of the water and sanitation crisis facing the world to have a far better understanding of what this means in practice.

A typical day starts with a coffee. That cup needs washing. Turn away for a moment and that running tap spouting forth unlimited crystal clear water -- water free from disease -- can take 1/8 of your daily allowance in the blink of an eye. Want a shower? Want to use the toilet and flush it? Forget about drinking much for the rest of the day and get used to the ensuing dehydration headache.

The simple yet resoundingly powerful message the 4Liters challenge has imparted to me is that, in the wealthy global North, it is near impossible to live on four liters of water a day. This is a vicious reminder of the stark inequalities we face in a world where so many people simply cannot, as much as they may want to, live on more.

The concept of "virtual water" is instructive here. Developed by Professor Tony Allan, a University of London geographer, virtual water is a means for calculating the amount of water locked in to the food and goods we encounter in our everyday lives.

That cup of coffee -- it didn't take up just the water used to pass through ground coffee beans to produce the daybreak elixir of choice for so many. Allan's calculations show it used an astonishing 140 liters to get from farm to cup. Steak at lunchtime? If it's grain-fed, you're looking at using an astounding 13,000 liters of water per kilo. Want to track the virtual water of items you encounter in your daily life? Grab the iPhone app -- and be mindful of the water used in its production that is so clean it can damage human bodies.

Now let's take a look at this from the other end of the spectrum. More than one in six people worldwide -- 894 million -- don't have access to 20-50 liters of safe freshwater a day. Accessing 50 liters is considered by the UN to be the amount needed for a healthy lifestyle.

And how do they get this water? It's a much longer and more risky journey than reaching for a tap -- women in the poorest parts of the world spend some 200 million hours a day collecting water, walking an average of about 4 miles a day and carrying a weight of about 44 pounds on their heads.

Such long walks raise immense threats of attack -- a situation that's even worse when searching for a place to go to the toilet after dark. And the threat doesn't end when the water eventually arrives at home. It's estimated that about 70 percent of the world's blind are women, many of whom have been infected, directly or through their children, with trachoma, a bacterial eye infection occurring in communities with limited access to water -- and that's just one of many health issues associated with dirty water.

This all has ramifications in terms of what people could have been doing instead of fetching water and then suffering the ill health it can cause. They could be working in jobs to provide for their families, that support a local business to grow and employ more people while adding to a national tax base. They could be enabling their children -- or even themselves -- to be enrolled in full time education heightening their chances of escaping the cycle of poverty.

At the heart of this is the issue of choice. The poorest have no choice and, as I learned, we in the global North have less leeway than one might think. But as 4Liters shows, we can learn more about our own water consumption, and we can be more measured in our use of this precious resource. If we as individuals seek to make this first step, however difficult, we will be actively supporting any policies that seek to redress the balance and at the same time be living with greater solidarity for our fellow humans who have so little.

Today, at the Budapest Water Summit, where talks are ongoing towards what a future water and sanitation "sustainable development goal" should look like, UN Special Rapportuer on the Right to Water and Sanitation, Caterina de Albuquerque, made a telling point. She explained that she had sought to show her 10-year-old daughter how inequitable global access to water and sanitation is.

Her daughter understood -- crucially, she understood it was wrong. As Alberquerque asked, if her 10-year-old daughter can understand this, why can't we all? More to the point, why can't we do something about it, so that the poorest are no longer faced by a life of thirst, the threat of disease, and sexual assault in their search for either a toilet or a drink, while for the richest, the largesse of our seemingly unlimited access to water faces us in almost everything we consume.