IWRA Proceedings

1. Introduction

Households in the developed world remain a relatively little studied scale in the analysis and management of water resources. However, in recent years a growing number of studies are focusing on specific areas of household water consumption, such as kitchens (Richter and Stamminger, 2012) or bathrooms (Makki et al., 2011). Contributions on outdoor water use are also becoming more widespread partly as a result of interest in conservation (Sauri, 2013). However, few studies provide disaggregated information of household water consumption into end use categories, including both indoor and outdoor uses. There is also a relative lack of studies on domestic water resources from different origins and quality (rainwater, groundwater, reclaimed water, grey water, bottled water, purified water, etc.) in addition to potable water from the network and on their actual use applying the concept of fit-for-purpose and avoiding thus the use of high quality water for uses that do not require the best quality. At home, most of the water consumed belongs to secondary uses such as garden irrigation, toilet flushing or washing, and only a small percentage of the total (about 3 percent in Europe according to Eursotat 2007) is for cooking and drinking. A better knowledge of end uses and the different water sources satisfying these uses would be of great interest for the preparation of structural and contingent plans of domestic water management.

In Catalonia, domestic water consumption from public networks declined almost 10% between 2007 and 2013, while in the same period the population increased by 5%. As a result, per capita domestic water consumption has been reduced by 14% corresponding to 114 litters per inhabitant per day in 2013 for Catalonia and to 106 litters per inhabitant per day for the Metropolitan Area of Barcelona, one of the lowest values in Europe and the developed world. In this reduction, two main factors have played an important role: recurrent droughts in recent years, particularly the 2007-2008 episode, and the economic crisis occurring right afterwards. The fiscal crises of public water regulators forced to increase prices and taxes producing further declines in consumption. In this context, the adoption of water-saving devices in households (in part stimulated by national and local regulations) and the possibility of using water from sources other than the network should be taken into account as relevant factors for explaining the reduction in domestic water consumption.

The purpose of this study is to explore the degree of penetration of efficient domestic water technologies and water treatment systems in Catalan households through two main sources: first, the companies and manufacturers in the association AQUA ESPAÑA, and second, the domestic consumers. The combination of both sources of information may provide a robust picture about the presence of these new technologies in water end-use points of Catalan households. Enhancing the knowledge in this niche will enable better targeted water-saving measures for each domestic micro-component. Our basic rationale is that decisions taken in the intimacy and privacy of households, when taken all together, have a remarkable influence on water demand trends and as a result, in public and private policies regarding water in urban areas.

2. Methods/Materials

With the above purpose in mind our methodology will consist in the design and administration of semi-structured interviews to the thirty-five companies belonging to AQUA ESPAÑA domestic sector and in the design and administration of a telephone survey (N=1000) on uses and habits of water consumption to a sample of Catalan households stratified according to socio-demographic and territorial characteristics. Data from the public survey will be statistically contrasted with socioeconomic profiles of respondents, and both surveys will be compared according to a matrix of household water uses (indoor and outdoor) and types of water resources available. This will be supplemented with an assessment of different technologies currently existing in the domestic water market.

3. Results and Discussion

It is expected to find important differences between rural and urban areas as well as between areas of low and high urban density both concerning the penetration of new domestic water technologies and the types of alternative water resources available. Regarding indoor/outdoor uses, this distinction is more likely to be found in low density urban areas (gardens and swimming pools) and in rural areas than in high-density urban areas. However, the typology of outdoor uses may vary in each context (pools, garden, orchard, small livestock, etc.). The presence of private wells or tanks to collect rainwater is more likely in rural areas while reused or reclaimed water will be more common in urban areas.

The presence of domestic water treatment systems such as water softeners is partly explained by physical criteria such as the water hardness in the area, although this is a widespread characteristic throughout the region. Other treatments like reverse osmosis systems or jars equipped with filters or the consumption of bottled water could be explained by economic criteria (price and income), consumer preferences (bad taste of tap water, degree of confidence in the authorities or companies responsible for the supply and the quality of tap water, environmental awareness) or health concerns (related to the medicinal properties of the different waters).

Finally, the presence of saving devices at the end use points is closely related to the age of the building (new buildings and renovations are required by law to incorporate these devices), as well as other local regulations (water saving ordinances), the income and consumer awareness regarding water conservation and cost savings in the water bill.

4. Conclusion

Our study attempts to make a contribution to more detailed assessments of domestic water consumption by unravelling both the typology of water ruses in households and the different "waters" employed. Generally we observe a growing complexity of both uses and sources of water especially in low density urban areas and in rural households. The study also attempts to identify problematic areas in terms of water quantity and quality; areas where alternative resources (greywater, rainwater) may be more widespread and also areas where the penetration of new domestic water technologies, especially filter systems, is more intense. These results will in part depend on socioedemographic and economic aspects. All in all, the resulting picture will unravel key aspects for improving water planning and management practices in both rural and urban areas in Catalonia.

1. Eurostat (2007) Consumers in Europe – Facts and figures on services of general interest.

2. Makki, A.A., et al. (2011) Revealing the determinants os shower water end use consumption: enabling better targeted urban water conservation strategies, Journal of Cleaner Production.

3. Richter, C.P. and Stamminger, R. (2012) Water consumption in the kitchen - A case study in four European Countries, Water Resources Management, 26, 1639-1649.

4. Sauri, D. (2013) Water conservation. Theory and evidence in urban areas of the developed world, Annual Review of Environment and Resources, 38, 227-248.