How water consumption changes at home during a drought: “I flush the toilet one out of every two times I go to the bathroom”

The serious drought suffered by Barcelona and its metropolitan area is already changing the habits of Barcelona residents. “If you see that I haven't flushed the toilet, it's because I do it every other time,” she explains to her granddaughters Ester Marcos, 70 years old. The same thing happens at the Fort Pienc school in the Catalan capital: the teachers have explained to the five-year-old students that when they pee they must flush the toilet every three students, says Mar Maltas. And emptying a cistern can involve about 10 liters of water, a not insignificant amount in a context of water stress. How much water do households in Spain use and what other things could be done to save?

He National Study of Drinking Water Supply and Sanitation in Spain 2022 points out that the provision—quantity—of urban water is 245 liters per inhabitant per day. However, around 20% is non-registered water (which is lost or not billed), so the effective amount is about 200 liters. Of them, 67% goes to homes, almost 11.9% to industrial and commercial consumption, and 20.7% to municipal uses, according to data from the Spanish Association of Water Supplies and Sanitation (AEAS). Catalonia has just declared a drought emergency, which means limiting the total amount to 200 liters per person per day for six million Catalans in Barcelona and Girona; But it must be taken into account that this amount does not only go to homes: it includes both losses and commercial, industrial and municipal consumption. Everyone will have to reduce their use. On Friday, Andalusia also limited consumption in the province of Málaga and in certain municipalities of Cádiz to 160 liters per person per day, while in some areas of Almería and Granada a maximum of 200 liters has been implemented.

AEAS brings together public and private companies that manage urban water in more than 2,000 municipalities (77% of the Spanish population) and, through its measurements, calculates that the average urban water consumption was 131 liters per inhabitant per day in 2022. “We still do not have the definitive data for 2023, but we believe it will be around 125 liters. And the trend is downward: in 2006 we were at 162 liters and since then we have reduced waste by more than 20%,” says Pascual Fernández, president of AEAS. The INE, for its part, conducts a survey of distribution companies in which it obtains a similar figure: 133 liters per person per day, which allows consumption to be compared by communities.

What are those 133 liters spent on? David Saurí, professor of Human Geography at the Autonomous University of Barcelona (UAB) and expert in water management, explains: “Where we consume the most water is in the bathroom, because it brings together the shower or bathtub, the toilet and the sink. Depending on the case, it can represent up to 70% of consumption at home. The rest goes in the washing machine, dishwasher, and water for cooking and drinking. [esto último, un 5%]”. Curiously, Saurí continues, “in Barcelona, ​​around 50% of households drink bottled water, partly because it sometimes has a lot of lime or bad taste, although it is drinkable, and partly because of tourist influence: visitors buy mineral water and produce an imitation effect.”

A shower uses 50 to 100 liters – depending on the weather and whether there is a flow reduction head – while a bath needs 200 to 300. The toilet cistern uses between eight and 10 liters each time, while washing your hands hands can be from two to 18 liters (depending on how long the tap is open).

When it comes to appliances, there is a lot of variation between the most and least efficient ones. “In washing machines, consumption ranges between seven and 20 liters per kilo of clothing, so a nine kilo washing machine uses between 63 and 180 liters per wash, depending on whether it is more or less efficient. We have done a survey that shows that they are used three times a week, which represents a cost between 756 and 2,160 liters per month. In addition, the ECO program reduces water consumption on average by 30% in each wash,” explains Enrique García, spokesperson for the Organization of Consumers and Users (OCU).

The other appliance that needs the most water is the dishwasher. “A 10-place dishwasher, the most common, uses between 8 and 16 liters per use. The OCU survey indicates that on average it is used once a day, which represents a waste of between 240 and 480 liters of water per month. ECO programs use 20% less water,” García continues. Even the least efficient dishwasher uses less than washing dishes by hand: according to the Institut Metropoli of Barcelona, ​​washing dishes with a full sink can require up to 60 liters.

Both the NGO Ecodes and Barcelona City Council have published guides to help citizens save water, with ideas such as incorporating flow-reducing devices in taps, showering instead of bathing, or installing double-load cisterns (or inserting a sand bottle inside). In addition, they suggest turning off the taps when they are not in use (for example, when brushing your teeth), never using the toilet as a trash can and not defrosting food under running tap water.

Savings measures

With the serious drought, the people of Barcelona are already doing it. Pepa Amado and Luis López, who are over 50 and live in the Indians neighborhood, have always been careful with water. But now more. When they cook pasta or vegetables, they do not salt the water and use it to water the plants. They rinse all the dishes with the water that fits in a basin. They flush the toilet with the water they collect from the shower before it gets hot. When washing your hands, do not turn on the tap fully. And, when it rains, they take buckets out to the community roof to collect water. “Sometimes we have collected 70 liters,” says Amado, alarmed by the drought: “All these measures are things that had always been done and were abandoned for convenience and because it seems that we have extra money. “Water is a good that is running out and this time it is serious, people are not aware of what it would be like to live without water.”

From the Gòtic, in the heart of Barcelona, ​​Agnès Giner (56 years old) summarizes her savings like this: “Washing machines full, before I didn't always fill them; shorter showers and taking advantage of cold water, and a portable dishwasher that uses five liters for the entire day's dishes.” Ella Giner explains that it has always hurt her “to think that toilet water is mouth water.” “We are a country of droughts, I don't understand how gray water is not used for the toilet,” she says.

In this sense, Barcelona City Council has announced an ordinance to require new buildings to use gray water. Giner became desperate a few days ago when he starte
d looking at Google: “I couldn't believe how many buildings in this neighborhood have a swimming pool.” And he summarizes: “Saving measures in private consumption serve to raise awareness, but the problem is structural and growth model: we cannot have hotels with swimming pools, fill bathtubs or water golf courses and avocados as if this were Iceland.” Other water saving systems at home that are beginning to spread by word of mouth are filling a couple of liter and a half bottles and putting them in the toilet cistern, to reduce its capacity; use the water from cleaning the lettuce to scrub; or save the shower water in a bucket before it gets hot.

Saurí, from the UAB, highlights that urban consumption has been declining for two decades: “On the one hand, because toilets, showers and appliances are increasingly more efficient; secondly, the price of water has been increasing, especially in the highest reaches, where the price skyrockets; and third, people are becoming more aware. The previous great drought in Barcelona was in 2008 and since then people have tried to maintain rational consumption.” In fact, domestic consumption in the Catalan capital is 105 liters per person per day, according to the Barcelona Metropolitan Area. “The OECD says that 100 liters per person per day is the minimum for our level of development, and in some cities we are already getting close,” he adds.

However, there are many differences between someone who lives in an apartment and a chalet. “Single-family houses spend much more because they have a lawn, garden, swimming pool and can wash the car outside. Irrigating the lawn can be a third of a house's annual water consumption,” Saurí continues. The Metropoli Institute of the Autonomous University of Barcelona carried out a study for the Metropolitan Area of ​​Barcelona (AMB) that demonstrated it with data: in chalets, 62% is spent inside, 16% on irrigation and 22% % in swimming pools. “In addition, the number of people living in a home decreases consumption per person,” says Elena Domene, head of the institute's urban sustainability area. Julio Barea, Greenpeace water expert, adds: “If someone fills their pool during a drought alert, they should be penalized, but we don't know if this is being done. In addition, large water consumers should be published, which is not being done either.”

You can follow Climate and Environment in Facebook and xor sign up here to receive our weekly newsletter

_