USA could save 14.458.521.278.757 litre drinking water each year. This is how.
Drinking water consumption differences between USA, the Netherlands and Belgium as part of the Water Footprint shows Americans should use front-loaded washing machines and review inefficient toilet flushes installed.
The UN and the Water Resources Group predict a global gap between existing accessible, reliable supply and 2030 water withdrawals of up to 40%, assuming no efficiency gains. To solve the gap in the next 10 years we need to understand better HOW and WHY we use water – we need to understand our water footprint. When we understand, we can change habits, regulations and innovate to increase water efficiency. In this article, I compare drinking water consumption as part of the total water footprint of the US, the Netherlands & Belgium allowing to formulate some first recommendations.
Your water footprint can be split into different categories :
Indoor visible drinking water consumption: all water use all of us understand like taking a shower, washing your hands, using the washing machine or dishwasher ... Research disaggregating consumption record consumption per activity and multiply this with frequency. This method allows to identify water guzzlers in the home.
Indoor hidden drinking water consumption caused by leaks from devices, taps & mixers, leaking pipes, micro leaks, … The world lacks sufficient data on leaked water in houses. Data from the US indicates that on average 13% of drinking water consumed is leak water, but comparable data for NL and BE was not found or was estimated to be extremely low. This seems to be a problem of the previously mentioned survey method as people do not know their leaks, or do consider larger leaks as one-time events and therefore exclude them (let alone unintentional use of water). Yet, it is known by leak experts that around 1 in 3 homes have toilet leaks (easily worth hundreds of litres of water a year) and that 2% to 3% of homes report a leak to their insurer every year. Therefore, the same 13% leak percentage for the US has been used for BE and NL as well as a proxy (probably for those 2 countries on the high side).
The water footprint excluding indoor consumption is an unimaginable amount of water from other water sources not measured and water used to create products and services you use/buy on daily basis (best approach you'll find on waterfootprint.org, Hoekstra and Mekonnen). The worldwide average water footprint in 2011 (including consumption) was estimated to be at 1.380 m3 per person per year in 2005 (study of 2011), and at 1.240 m3 per person per year in 2017. This means every single day to live the way we live we need 3.397 litre water per person per day! In a later article, I will dig deeper in this part of the water footprint.
The consolidation of these numbers can be found in the table below. Numbers are directional as not all studies have been done using the same methodologies. Nevertheless, we can draw first conclusions, especially on visible indoor water consumption.
The main conclusion : USA consumes on average around 2 times the amount of drinking water, a massive difference considering all 3 countries are developed, modern nations. There are though some simple explanations for the differences in water consumption, driven by habit/culture and regulations :
Most of toilets in the US are so called siphonic toilets (today’s toilets at 4,8 l per flush – avg/day/person 24 l) that consume based on use roundabout 33% more water then European style wash-down toilets (today’s toilets at 3/6l per flush – average/day/person 18 l) on average. The current average flush in US is at 9,8 l/flush whereas in Europe dual flush is standard since a long time. driving down consumption significantly. In Belgium for example around 80% of the times the small flush is used when it should be used. Further, siphonic toilets clog much easier as the trap has a much smaller diameter and therefore need often that extra flush.
Top-loaded washing machines used in the US, although cheaper to build and easier to access, have only an average washing quality and consume 2 to 3 times more water per washing cycle than front-loaded machines used in Belgium and the Netherlands. The same person in the US uses around 37 litre drinking water per day to wash clothes, versus around 14 litre in Belgium and the Netherlands. A switch to front-loaded washers in the US will significantly reduce water and energy use and improve the cleaning quality and the longevity of clothes.
The main difference between Belgians and Dutch (and Americans) is their personal hygiene. As half of the Belgians wash themselves more frequently at the basin than in the shower and 75% of the Dutch shower every day (65% of Americans), the average consumption for showering is with 51 l much higher in the Netherlands. Belgians on the other hand use 9,4 litre at the washbasin, which is twice as much as the Dutch.
Another striking fact is the difference in total consumption between neighbouring countries Belgium and the Netherlands. One of the main explanations is rainwater reuse. Rainwater recuperation in larger rainwater tanks for use in toilets and washing machines is a common accepted practice in Belgium. Around 10% of water consumed by Belgians is rainwater and is therefore excluded from the numbers on drinking water consumption.
And then there are leaks: in US around 30 litres per day per capita is leak water. Intelligent technology to detect and stop leaks from happening is now readily available - chances on reducing to the absolute minimum are big. Take a look at GROHE's Sense Guard.
Conclusion : Gigantic improvement potential
When 382 million Americans adopt the drinking water profile of Belgians – a whopping 14,46 km3 can be saved. This is close to the yearly freshwater abstraction of Belgium and the Netherlands together (28,74 million inhabitants), and higher than the total yearly freshwater abstraction of the UK (11,75 km3) alone (66,65 million inhabitants). Reducing leaked water to zero would further improve by 1,6 km3.
Increasing residential rainwater recuperation could then be a solution to drive further efficiencies, also in Belgium and the Netherlands. Last but not least, recycling/reusing water in showers is then the biggest potential for all nations to improve consumption - this will be driven by technological progress in the coming years.
Reducing water consumption is possible, with existing technologies first.
