First assignment of group n° 120


First description of our project

DWO - Drinking Water Optimisation

What Problem do you want to solve ?

It’s so easy to consume water that we throw away millions of litres.

While an American consumes 600 litres of water per day, a French citizen is consuming 137 litres, and a Sub-Saharan only 10. Among these, some studies revealed that only 7% of the water we consume is used for our alimentation. What are used the other 93% for?

Let’s see some figures:

  • Flush: 10 litres
  • Shower: 60 to 80 litres
  • Bath: 150 to 200 litres
  • Washing machine: 90 litres
  • Dishwasher: 25 to 60 litres

Even though one has to admit that it is hard to cut down all these habits for now, we can still put some efforts in trying to reduce the consumption of drinkable water.

That is exactly the challenge we want to deal with: optimise our resources of drinkable water. Concretely, we are planning to reuse drinkable water to redirect them in domestic facilities that doesn’t necessarily need fresh and clean water.

Why does this problem exist?

Natural resources are finite and non-renewable, and we put harsh pressure on them. Extraction destroys landscapes and natural ecosystems. Some solutions are slowly raising up, but depleting actual resources will put future generations in a situation of material and resources penury.

What does it mean?

It means that the quantity of freshwater available is currently 6 600 cubic meters of water per year and per person, and this number is going to fall under 1 700 cubic meters for more than half of the world, within a decade.

783 million is the number of person who still doesn’t have access to drinking water, which means 11% of the world population.

If nothing changes, the situation would get even worth; by perpetuating this consumption habits, scientists plan a “hydraulic stress situation” for the horizon 2025. Meanwhile, the world’s population should reach 9, 5 billion people in 2050. It means that the demand of water is going to rise up to 55%! How will we feed everybody? We would have to improve our productivity and, in fact, our water consumption. That is why we should start to focus on all several possibilities to reduce as much as possible the use of drinkable water. The problem we want to solve is concerning one of those solutions.

What breakthrough are you commited to creating?

If one takes a look at the several ways to clean dirty water, including i.e. filters (natural or mechanical), chemicals, holding ponds or other storage facilities, it is pretty obvious that it is our responsibility to start putting things forward in order to change our habits.

We would like someone to create a system which takes the water coming from the shower in order to supply the toilets, so as it could function independently from drinkable water supply. During a shower, the water could be collected and stocked in a tank, where micro-particles and main bacteria would be filtered. We chose the shower as it’s the most consuming water element in the house.

So, from now on, we put this forward in order to promote the idea of reducing drinking water consumption. The sense of our approach is to let anyone think of a concrete project that would solve this problem. Ideally, our solution can be applied in existing houses, as well as houses that are going to be built. We want to provide a solution easily buildable and cheap. And once the solution found, we would like to unable anybody to build up its own system at home that works in entire autonomy.

We really hope that our project will be successful in order to expand our solution to the entire house (washing machine, dishwasher…). Indeed, if we think further, we are trying to give a start to a general movement committing the reduction of our water consumption at home. We truly believe that by finding a solution to the problem of toilet’s supply, it will urge further researches in order to allow a house to work in quasi-autonomy (concerning water supply).

What interest for you?

The more people you are in a house, the more you consume water. Furthermore, water is a limited resource, that’s why it might get more and more expensive by the time. Our project is multidimensional: on the one hand, it has an ethic and environmental dimension and on the other hand, an economic interest.

Potential experts already identified

Please mention the potential experts (name, affiliation, likelihood to convince him/her to join the final panel)

  • Laure Chiarella - Engineer urban and fluvial hydraulics engineer - Ecole polytechnique universitaire de Lille
  • INGEROP - Water and environnement - Villeneuve D’Ascq
  • City hall Lille - Environnement pole

Resources used by the team

Alizée de Wazières
  • Dame Ellen MacArthur: The surprising thing I learned sailing solo around the world
  • Latitude responsible: DANONE communities project 1001 fontaines
  • Clinton Center: earth day festival 2008

Book : Adjou, N. Prabhu, J., Ahuja, S. et Boillot, JJ (2013), Innovation Jugaad. Redevons ingénieux !, Editions Diateino


  • The Guardian: Reimagining New Orleans as America's most resilient waterfront city
  • The Guardian: Surge in tech investment shows the days of cheap water are over
  • Alternatiba website
  • DDoogle website
  • TakePart: College Students School Industry on How to Make Greener Products
Tabatha Ecarlat
  • C'est pas sorcier - Eau en danger
  • C'est pas sorcier - Notre eau maltraitée
  • C'est pas sorcier - Zimbabwe : de l'eau pour tous, de l'eau pour toute la planète

Book : Braungart, M. et McDonough, W. (2011), Cradle to cradle: Créer et recycler à l'infini, Edition Alternatives


  • Up Inspirer: La douche du futur consommera moins
  • Up Inspirer: Comment monter son entreprise sociale ?
  • Oui Share: On the path to zero waste
  • Magazine Good: NASA announces evidence of liquid water on the surface of Mars
  • Magazine Good: A floating garden blooms on NYC’s most toxic waterway
Tanguy Haize
  • BIO UV: BIO-SUN, de l'eau potable partout et pour tous
  • IIT Madras: Affordable drinking water purification using advanced materials
  • Illustrated ideas's channel: Water, The World Water Crisis

Book : « La crise de l'eau ? » de Patrick Philipon – Perrin - 29 mai 2008


  • TrojanUV: Réutilisation indirecte de l’eau potable
  • Centre d'information sur l'eau: Les usages de l'eau - les usages domestiques
  • United State Environmental Protection Agency: Water Sense - Start saving
  • TrojanUV: Réutilisation de l’eau
  • Greywater Action website
Margaux Wehrle
  • Top documentary films: A world without water
  • Top documentary films: The nature of cities
  • Top documentary films: Unwasted - The future of business on Earth

Book : Manier B. (2012), Un million de révolutions tranquilles : travail, argent, habitat, santé, environnement, ... Comment les citoyens changent le monde, Editions Les Liens qui Libèrent


  • Graie: Les usages de l’eau potable
  • Sharing water: « Engaging business Why watershed approaches are important to business sustainability »
  • WBCSD West Coast Conference Summary: The Business of Water: Scaling Up Water Sustainability Solutions in the U.S
  • Eau de Paris – Guide pratique Branchement d’eau non potable
  • Fast Coexist: Water is a fuel with no alternative
Lucie Chavant
  • TED talk: Joe Madiath - Better toilets, better life
  • TED talk: Ludwick Marishanec - A bath without water
  • TED talk: Fahad Al-Attiya - A country with no water

Book : Hervé-Gruyer, P. et C. (2014), Permaculture : Guérir la terre, Nourrir les hommes, Edition Actes Sud


  • Blog de la consommation collaborative: Non, la consommation collaborative n’est pas une menace (et autres idées reçues)
  • Blog de la consommation collaborative: La nouvelle consom’action des familles
  • The Guardian: Ikea's net positive approach is its 'licence to operate'
  • The Guardian: Imagine a world without waste: it's possible with a circular economy
  • The Guardian: Circular economy inspires young people to change the world
Mathilde Rovira
  • La ville de demain: Les défis de l'eau potable et la gestion des ressources en eau
  • Arte: La gestion de l'eau
  • TED talk: Joe Madiath - Better toilets, better life

Book : Barthélémy, A. et Slitine, R. (2011), Entrepreneuriat social : innover au service de l'intérêt général, Editions Vuibert


  • Sustanabililty: Latin America trend series: water crisis challenges business as usual, Spurs Innovation
  • WBCSD: Turning waste into resource: CH2M recognized for its work on water reuse
  • DDoogle website
  • The Guardian: Clean water could take a central role in the 2016 presidential debates
  • Building: Sustainability: managing water consumption
Baptiste Caron
  • Envoyé spécial: Reportage du 19/06/2015
  • Zango Média: La Maison Autonome, économie, récupération et traitement de l'eau
  • TV5 Monde: Eau: Les enjeux de l'or bleu

Book : Sempels, C. et Hoffmann, J. (2012), Les business models du futur : créer de la valeur dans un monde aux ressources limitées, Pearson France.


  • Wiki How: How to save water?
  • International Policy Digest: The Growing potential for water wars
  • Forbes:Top 5 ways to save water at home
  • Le point: La maison du futur sera écologique et magique
  • Movilab: La régulation de la consommation d'eau dans le secteur de l'hôtellerie-restauration

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