In the context of the project Water-Energy Nexus: a sustainable binomial, it is proposed to create a database based on two Bachelor’s and Master’s Theses.

It has been proven that water is a scarce resource in nature and must be conserved in its entirety, maintaining its qualities. On the other hand, energy is also essential for the proper functioning of current life. These two resources are addressed in the 2030 Agenda with two specific goals. In the case of water, the Sustainable Development Goal (SDG) number 6, and in the case of energy, goal 7. At the same time, many other SDGs can be indirectly worked on: 13, 11, 3… In this project, the interrelation between water and energy is proposed, regarding the treatments they undergo in the Integral Cycle in urban areas:
- Drinking Water Treatment Plant.
- Wastewater Treatment Plant.

The goal is to obtain the value of kWh required to obtain 1 m³ of water and to treat and return it to the environment.

The study area for this work, as a pilot project, is proposed in several areas of Catalonia, and with the development and implementation of the complete project, the aim is to cover the entire territory of Catalonia. The data obtained should allow for conclusions to be drawn by regions and treatment types, as well as the characteristics of different services.

Currently, with these two works (one bachelor’s thesis and another master’s thesis), the aim is to work in two areas of Catalonia and, with the implementation as a CITIZEN SCIENCE PROJECT in Secondary Education Centers (students aged 14 to 18), gradually obtain data from the rest of the municipalities or most of the counties.

In all cases, the urban water cycle is studied in terms of its operation, but with special emphasis on the energy consumption it represents. It is necessary to differentiate the energy required for the treatment and distribution of drinking and wastewater. Ultimately, the goal is to assess the energy required to supply drinking water and ensure its sanitation and return to the environment, so that the results can be compared by location.

Keywords: Citizen Science Project, Urban water cycle, Water-energy nexus, Sustainability.