The intensive socioeconomic development recorded in European countries since the second half of the twentieth century has, among other aspects, led to a change in lifestyle and an increase in urban-residential areas [1
]. In the 2000s, different reports that were prepared by the European Environment Agency such as the State of the Environment [2
] and Urban Sprawl [3
] highlighted that in the previous twenty years, built-up areas in Europe had grown by 20% and they highlighted the possible repercussions of this dynamic on resources such as land and water, energy demands or the generation of waste [4
Since the beginning of the twenty-first century, significant morphological and social changes have been taking place in many Spanish cities [5
]. During the aforementioned real estate boom, the total number of properties in Spain increased by almost five million (25%) between 2001 and 2011 [6
]. Until 2008, in Spain, urbanized and built surfaces increased, together with processes of expansion and the modernization of cities. This has produced contradictions and internal conflicts linked to the overconsumption of resources (land, energy, water) and pollution (air, water, heat islands, urban solid waste) [7
One of the features that characterize the Spanish Mediterranean coast as a result of the recent real estate boom (although its origin has been related to the spread of urban-residential uses since the end of the 1960s) has been the spread and generalization of low-density urban types (“urban sprawl”) [10
]. In some areas of the Alicante coast, this urban sprawl represents 60% of the total built area [10
]. Its expansion is related to the search for less dense, congested urban spaces rather than the town centres and the expansion of residential-tourism development in coastal areas [11
]. This type of development is characterized by the presence of outdoor elements, such as gardens and private swimming pools, that consume high amounts of water compared to the traditional compact urban model [12
]. In this respect, in Australia, Hurd [16
] states that approximately half of the water used by these households goes to watering the garden and/or filling up the swimming pool. This development type has also spread in other European Mediterranean countries, such as France [17
], Italy and Greece [1
], along with in tourist and residential areas of the United States [18
], Australia [19
], Japan [20
] and South America [21
Despite the significant development of garden areas associated with urban sprawl and their impact on water consumption, the demand generated by these spaces is a topic that has only recently been dealt with in Spanish scientific literature [4
]. Relatively little is known about the characteristics of these spaces or the behaviour of their owners. Furthermore, there is a tendency to think that single-family gardens use water in excess as a result of the lack of knowledge about gardening or the low cost of the resource. In Spain, recently, a few studies that consider these lines of research have been carried out in the Metropolitan Area of Barcelona, Girona, Granada, Balearic Islands, Seville, Zaragoza and, in recent years, on the coast of Alicante [4
The increase in urbanization associated with the real estate boom and the proliferation of urban sprawl development types have demonstrated the unsustainability of the model established due to the high levels of water consumption required [10
]. This situation gets worse in periods of drought. However, in the majority of European and Spanish urban agglomerations a drop in water consumption has been observed since the middle of the 2000s [11
It is therefore necessary to gain more insight into the factors affecting domestic water consumption and their interrelationships. Studies on water conservation, and especially those on urban water conservation in the developed world [24
], have mainly focused on certain areas of North America [25
] and Australia [26
]. By examining other environmental settings, a wider variety of factors influencing water conservation practices can be assessed more comprehensively. Most notably, the considerable influence of different community water consumption models and the potential of urban and regional planning for water conservation have to be put at the forefront of research and practices on this topic [27
]. This is of vital importance in terms of planning future water demand scenarios, taking into account continued urban population growth, episodes of water stress, drought events and the impact of the climate change on the availability of water resources, among other issues [28
]. Various aspects of the factors affecting the levels of demand for water resources have become priority research topics in recent decades, especially in water-stressed areas that have experienced particularly intensive urban development processes [30
]. The relationships between these factors must be analysed along with the changes in water-saving behaviour [31
]. In the last few years, studies have also been carried out in Europe that analyse the reasons why water consumption has decreased [11
]. Numerous studies associated with these results have come up with possible reasons for this decrease that include:
Technological innovation associated with installing new water-efficient appliances as well as water saving devices at home (taps, bathroom fittings, etc.), which have become popular since the late 1990s [22
Greater environmental awareness among the populace about saving water, thanks to more organized campaigns, especially in times of drought [23
]. Interesting results have been obtained in the studies about the reduction of water consumption outdoors. In recent years, homeowners have greater environmental awareness. This becomes obvious, for example, in the typology of their gardens, where native species that adapt better to the local environment and require less water are becoming more popular. This was confirmed in a study by Morote and Hernández [39
], who reported a change among homeowners from having central and northern European to Mediterranean-type gardens, which adapt better to the climate of the southeast Spanish coast.
The economic crisis has led to a drastic fall in incomes and increased unemployment. One of the strategies used in response to this significant downturn has been to cut back on all domestic consumption, including water, especially among the middle classes [22
Water rates and prices have increased at a time when family incomes have dwindled.
The efficiency of the Water Company supply networks has improved.
Drinking water has been replaced by non-conventional water sources (reclaimed water and rainwater) for public water, private gardens (in some residential areas) and street cleaning [40
An aging population. Morote et al. [11
] observed that one of the reasons behind the drop in domestic water consumption along the Mediterranean coastline was the increase in the senior population and the loss of a younger population due to migration that was prompted by the economic crisis, which erupted in 2007. These authors reported that a person aged 65 or more consumes 25% less water than the previous population segment (18 to 64 years).
The interest for the topic of study is accentuated in the case of the city of Alicante since water has always been a resource of vital importance in view of its scarcity and the increase in demands as from the second half of the twentieth century [41
]. In terms of supply sources, in south-eastern Spain, in order to guarantee the growing demands for water, both for the agricultural sector and for urban-tourism uses, traditional water solutions have opted for the exploitation of aquifers and water transfers [42
]. Furthermore, more recently, non-conventional sources (desalination and reclaimed treated water) have been used [44
]. These measures have been complemented with increased efficiency in the use of water for irrigation and supply [44
]. In addition to these factors, there is also a predominance of detached houses. This urban typology represents 60% of the total of the urban areas on the coast of Alicante [10
] and it is characterised by high water consumption compared to other urban typologies. Some studies [11
] point to the fact that more than 1000 L/day are being consumed compared to the 244 L/day in houses of the urban core. This high consumption becomes even more important if we take into account that: (1) the study area is a semi-arid region with a rainfall average of 350 mm/year; (2) the dependence on water resources from other regions (supply by the Tagus-Segura Aqueduct) and the implementation of desalination as “a new water resource” [45
]; and (3) the impact of climate change in the study area, which will become apparent through the drop in rainfall and exacerbated extreme events (droughts and heavy rain). Both processes—a drop in rainfall and exacerbated extreme events—will negatively affect the availability of water resources. The growing interest in this factor is highlighted by the necessity to improve water management, the homeowners’ perception of this factor (specifically, the level of relevance) and the measures they have adopted or will adopt to reduce water consumption.
As a hypothesis, it has been established that, owing to the increase in urbanization, and especially, the low-density urban development type, in recent years, cities have become less sustainable with regard to the use of natural resources (in this case water). This would have led to an increase in water consumption in the city. However, since the mid-2000s with the economic crisis, the significant increase in the price of water and the recurring drought episodes may have resulted in a change of the property owners’ perception of water saving and the water use trend in urban sprawl development types. These changes may have been due to the attempt to reduce the water bill and to consume water more responsibly. Therefore, one of the research questions would be to check to see if water consumption dropped in the detached houses at the end of the economic crisis (2014) or if it continues to drop; that is, highlight the water consumption trend. Moreover, it should be pointed out that the objectives of this research are, first to determine the perception of water use and the consumption of the population, and second, to compare that perception with the real water consumption, namely, the water bills of the owners’ homes that were included in the survey carried out by the water supply company. This becomes more interesting thanks to a few papers that have related these two issues and even more so considering the climatic characteristics of Alicante (scarce and irregular precipitations) and a water demand that is higher than the existing supply, which makes this region dependent on external water resources. However, as desalination has been promoted in recent years, perhaps this is the end of the “physical scarcity” of water resources as some authors have stated [46
The objectives of this research are: (1) to analyse the domestic water consumption trend in the study area (2000–2017), and (2) explore the water use and the characteristics of the detached houses and how property owners and residents in the area have introduced water-saving measures to reduce consumption after the economic crisis. After the introduction, which highlights the characteristics of the study area and the research problem, the materials, methods and results are described. Finally, the discussions and conclusions are presented.
As stated in the initial hypothesis for this research, urban expansion characterized by low-density urban development in the city of Alicante involved implementing an urban model that is not very sustainable; a trait that is exacerbated by the expansion of this development type coinciding with the most recent real estate boom. This study has corroborated the fact that water consumption in these households is high compared to other types. In 2017, water use per detached house amounted to 712 L per day in the study area. Some publications that have analysed water consumption according to residential property types have estimated modules of over 600 L/property/day for houses with private swimming pools and garden modules [11
]. However, other property types characterized by the inexistence of outdoor spaces or where these are very small and arranged in rows as in the case of terraced houses, water consumption is considerably lower. For this type, for example, Rico [53
] estimated on the coast of Alicante modules of 456 L/property/day. Regarding the city of Alicante, Gil et al. [22
] calculated that consumption was around 387 L in semi-detached or terraced houses, 322 L in properties located in blocks of flats and 244 L in households of the urban core (compact city).
However, despite the significant increase in the urbanized area, a regressive trend has been recorded for urban consumption in the majority of cities in developed countries since the end of the twentieth century [23
]. On the Spanish Mediterranean coast, Gil et al. [22
] explain that this trend is due to an amalgam of factors, among which it is worthwhile mentioning greater environmental awareness in favour of water saving, drought episodes, social and demographic changes (reduction of the population), the increase in the price of the water, more efficient technologies and the effect of the economic crisis since 2008. For the different urban typologies of the city of Alicante, Morote et al. [11
] calculated decreases that varied according to economic income and urban development type. In households of the urban core, from 5.86 to 18.84%, in blocks of flats, from 9.18 to 11.89%, in terraced houses from 2.64 to 5.12%. This percentage increases significantly for detached houses (2300 to 1052 L/day) (−54%) to a large extent, as a result of the high starting values and the role played by certain factors (price of water, economic crisis, environmental awareness, incorporation of more efficient technologies, etc.) [11
]. This trend, which corroborates the initial hypothesis, makes it necessary to analyse the importance of the role played by those factors in the reduction of consumption by this urban development type in the study area (a decrease of 43.27%).
To examine this matter in more detail, those surveyed were asked about their perception of the different variables that might have influenced this decrease. The three main factors were: greater environmental awareness, technical innovations (domestic appliances and systems that use water more efficiently) and the installation of water-saving devices. According to the answers of those surveyed in this research, environmental awareness is the topic with the greatest repercussion to explain this decrease. It is a factor that is also interrelated with the acquisition of domestic appliances and systems that use water more efficiently, together with the installation of water-saving devices. However, out of the eight factors proposed (from which the respondents had to choose), the price of water was ranked in fourth place and the economic crisis in fifth. These data are opposite to the results obtained by Morote and Hernández [39
] in the residential complexes on the coast of Alicante, which are characterized by the presence of a foreign population, where the reasons why changes are made in favour of water saving were the drought and the bad adaptation of Atlantic vegetation that they had planted in their gardens and the high price of water.
The social and economic profile of those surveyed shows that, to a great extent, they have not suffered from the recession, unlike those in other neighbourhoods of the city of Alicante. Other factors, in addition to per capita income, explain the adoption of initiatives aimed at reducing expenses. The increase in the price of water, the adoption of more sustainable consumption habits (for example, using the shower instead of the bath), using more efficient technology in domestic appliances, the environmental awareness associated with water-saving campaigns, or changes in the garden (replacement of Atlantic for Mediterranean plants) play a fundamental role. They have the spending power to acquire efficient, but also more expensive, domestic appliances, or, as a result of their level of education, they are more environmentally aware [22
]. The economic crisis may have encouraged these water-saving measures that were taken. The adoption of practices aimed at a more sustainable use of resources is a practice assumed by many echelons of society, becoming a structural fact that is still a personal saving habit.
With regard to the water bill (price of water and other concepts) the data show that, currently, more is paid for this resource than a decade ago, even with less water being consumed. The rise in prices (in addition to the increase in tariffs due to the incorporation of desalinated water and recovery cost related to implementation of the Water Framework Directive) could be a result of the current reduction in water consumption. The operating costs, depreciation, investment, etc., have not decreased. For this reason, to offset the lower consumption of drinking water, the supply company has been obliged to increase the price of water to maintain the service at optimum levels. Morote and Hernández [47
] prove that, for a water bill of 30 m3
/quarter, the price paid for this bill has increased by 92% since the year 2000 in the city of Alicante. Furthermore, this has occurred (and therefore the consumers have had to deal with it) in a context of economic recession. In the detached houses of this study the price of water has increased by 44% (2007–2017) (61 m3
per quarter and over). However, if the evolution of the consumer price index (CPI) and the family’s income is compared, the conclusion can be drawn that families have lost their purchasing power in relation to the increase in water prices. For example, according to the data provided by the INE [55
], the CPI of the province of Alicante between 2007 and 2017 increased 15.3%, but the income of families dropped 6.85% (25,802 €/year in 2007 and 24,034 €/year in 2017) [56
The relationship between the increasing water rates and their influence on the consumption drop cannot be considered to be a direct cause. The elasticity of water demand in relation to its price is low in moderate consumption, because a basic minimum consumption of drinking water must be covered (basic needs). Hence, the incorporation of water saving measures does not affect a reduction in the water bill, or the decrease in consumption [57
]. In addition to this, the water bill incorporates a series of variables that increases the final price, which are not associated with consumption. The use of consumption blocks as a saving element must provide for the non-elasticity in the price of water in the first blocks of consumption; the last blocks of consumption have a greater impact. This is related to consumption associated with external uses that are not included in the basic supply.
In terms of garden areas, one point that corroborates their effect on the high levels of water consumption is that the participants in the survey state that the main water use in their household is watering the garden. Furthermore, this is mainly due to their size and the presence of Atlantic vegetation. In this respect, it is appropriate to point out that the water requirements of a lawn on the coast of Alicante vary between 1000 and 1200 mm/year (depending on evapotranspiration), and this is exacerbated given that average rainfall in the city amounts to 311 mm/year [58
]. Morote and Hernández [59
] estimated that a garden on the north coast of the province of Alicante consumed 556.08 L per day (47% of the consumption of a detached house). In the Metropolitan Area of Barcelona (Spain), Domene and Saurí [51
] calculated that, in the summer months, 48.8% of total water consumed daily at home was used for irrigation. Higher percentages were recorded in the arid and semi-arid regions of the west part of the USA, where this reached 50% of total household consumption [60
]. Authors, such as Loh and Coghlan [61
], raise this to 56% in the city of Perth (Australia).
As a result of this research, it has also been ascertained that there has been a change of perception and management of the use of water outdoors, with a predominance of initiatives aimed at reducing consumption. Various processes corroborate this point. First, there is the reduction of gardens. Areas used as gardens stand for 35.13% of the plot, but paved areas have become more popular in the last decade. They currently represent 31.35%. The substitution of plant species is in second place. This is highlighted in the participants’ answers concerning the changes made outdoors where 33.33% of those surveyed said that they have replaced the lawn area and plants that require large amounts of water with succulent plants and they have paved part of the garden. These initiatives are complemented by the repair of leaks in the swimming pool. Therefore, these are measures to maintain and reduce consumption from the point of view of demand management. In addition to this, there is the possible impact of awareness campaigns and how they have been able to make a change and improve the environmental awareness of the residents; 66.67% replied that they remember these campaigns.
One of the questions included in the survey was the perception regarding reclaimed treated water. In this case, its use was related to the possibility of using lower quality water for activities that do not require drinking water (watering the garden). Furthermore, in this way, it reduces the pressure on the latter and increases the resilience of the urban model. A total of 100% of those surveyed said they were “indifferent”, and this resource was even ruled out. This lack of acceptance may be due to either the perception of the quality of the water or the fact that it is not used since there is no reclaimed water network for the watering of private gardens near their homes. As the reclaimed water distribution network in the different urban sectors of the city is a new concept, a precise evaluation of the role played by this new source in saving drinking water in the city cannot be obtained. Therefore, the survey shows a high value for the option “indifferent”, when the increasing importance of this type of resource in the urban use of water as a means of saving drinking water is evident. In the city of Alicante, it should be pointed out that in certain urban areas, reclaimed water is supplied to satisfy watering needs in private properties. According to the calculations of Gil et al. [22
], its incorporation, together with other factors, has led to a reduction of 54% in the consumption of drinking water between 2007 and 2013, from 2300 to 1052 L/property/day in detached houses in the urban district of Vistahermosa (city of Alicante).
Detached houses represent the urban development type that consumes the highest amount of water due to the existence of uses characterized by high demands such as watering the garden and/or filling the swimming pool. In the city of Alicante since the year 2000, there has been a decrease in water consumption of 43.27% in detached houses, from 1255 to 712 L/day. This process, which forms part of a more sustainable use of resources has not, however, been accompanied by a reduction in the cost of the water bill. On the contrary, users now pay 19.7% more than a decade ago. This demonstrates that, despite the fact that families have made a considerable effort to reduce domestic consumption, this has not led to a reduction in the water bill owing to the increase in the price per m3 of water (44.78%) and also in the different levies applied to consumption (treatment costs, for example, or charges associated with the maintenance of the service, which the company passes on in the price of the water). This increase has also had a dissuasive effect, since the band in which the price per m3 has increased the most has been that of the highest consumption (61 m3 per quarter and over, which applies to detached houses).
The reduction in water use has been a constant since 2004 in the city, as corroborated by the volumes billed by the supply company. However, the results deriving from the surveys highlight that the residents do not know exactly what their consumption is, or their trend is, either because they are not concerned or because they do not monitor their domestic expenditure in detail. They are more concerned (and have greater perception) about matters concerning the adoption of more sustainable practices in the consumption of water resources as corroborated by their responses, and this is shown by the decrease in consumption. The factors that have led to this reduction include, in order of relevance: greater environmental awareness, the existence of systems that use water more efficiently and the installation of water-saving devices. However, their choice, out of a total of eight factors, leads to the question as to whether these three have been influenced by the increase in the price of water and the economic crisis; meanwhile the average annual salary dropped by 6.85% from 2007 to 2017. That is, whether the reason behind adopting practices of this type is to save money owing to the increase in the price of water and the impact of the economic crisis. This has occurred with other domestic expenses that have been reduced. One of the hypotheses of this paper was to see if water consumption in detached houses had recovered after the end of the economic crisis in 2014. Despite the fact that the wealthier population of the city live in these houses (see Reference [11
]), the economic crisis has also affected these families. Furthermore, water consumption is no exception. Morote and Hernández [47
] have shown that in these households (detached houses), the ratio of fraud in properties connected to the network is similar to that detected in the poorest neighbourhoods of the city of Alicante. The increase in fraud, as these authors explain, is related to the need to save water owing to high levels of water consumption generated in this urban development type, which is exacerbated in periods of drought.
Finally, it is worthwhile pointing out that a change of paradigm and perception is taking place with regard to an improvement in water management with regard to measures for demand management. Perhaps the price of water is an indicator of the control of consumption, which has already been corroborated by other authors [62
] and this helps to make cities more sustainable and respectful when it comes to using natural resources [40
]. Furthermore, the uncertainty associated with the availability of future water resources must be mentioned, taking into account the climate change scenarios [63
], along with the need to set a goal to not compromise future generations in terms of the guaranteed availability of water.