About aiguaregenerada.cat

R+D+i projects and success stories related to the reuse of treated wastewater in Catalonia

Water, a scarce resource

The typically Mediterranean climate, with recurrent episodes of drought and heavy rains, together with the great demographic and economic heterogeneity of Catalonia are the cause of the great diversity of hydrological areas of the Catalan territory.

It is precisely this diversity that makes it extremely difficult to manage, not only to ensure the availability and quality of the resource, but also to ensure the health of the natural environment that provides it.

In order to face the conditions of water scarcity, it is traditionally considered on one hand the responsible use, trying to limit the consumption of water, and on the other hand routes of access to alternative water resources as it can be the generation of fresh water from seawater through desalination processes.

About reclaimed water

Reclaimed water is purified wastewater that receives additional treatment. It is optimal for industrial, municipal, agricultural and environmental uses, as well as for irrigating golf courses and recharging aquifers.

Historically, reuse was limited to irrigation in agriculture, but also what is now often considered unplanned indirect drinking reuse. For instance, that cities use river systems that contain wastewater generated by other residents and human activities upstream. This is the case, for example, in Barcelona, which uses water from the Llobregat river, which contains wastewater from Manresa, Martorell and other cities.

The inland basins of Catalonia concentrate 80% of the population but only have 40% of the natural water resources.

– Water data in Catalonia –

Regulation of wastewater reuse

A planned reuse

Usual reuse

Wastewater reuse is a common occurrence in most basins. Treatment plants discharge their effluents into fluvial courses that, in turn, are captured downstream, is the so-called unplanned reuse.

First regulation

The first regulation that regulates the reuse of water in Spain is Royal Decree 1620/2007, which establishes the legal regime for the reuse of treated water. In addition, to the imminent introduction of European regulations on minimum requirements for water reuse.

Since 1989

The planned reuse, which requires specific infrastructures, has been carried out in Catalonia since 1989, when the Costa Brava began supplying regenerated water from the Castell-Platja d’Aro WWTP to the Golf D’Aro. Since then, the volume of regenerated water has been gradually increasing but without accounting for a significant part of the water supplied to Catalonia.

Water reuse program of Catalonia (PRAC)

In 2009, the Water Reuse Program in Catalonia (PRAC) was published, which defined a series of proposals for management and investment in reuse. Although the potential of regenerated water to improve water availability in Catalonia is widely recognized in all published studies, there are still many barriers that limit its application.

Stabilization of water demand in the coming decades could be around 1000 hm3/year

– Water data in Catalonia –

Barriers to the reclaimed water use

Reclaimed water, a challenge

Regenerated water is one of the solutions to overcome episodes of scarcity, but it also involves many challenges that we at aiguaregenerada.cat want to help solve.

Economic cost

Significant economic cost that involves the construction of specific infrastructure (treatment and distribution), as well as the operating costs necessary to achieve the qualities set out in current regulations. However, technological improvements have significantly reduced the costs associated with regeneration and developed processes to regenerate water to the required quality in each case, without incorporating over costs arising from achieving higher quality water than required. In any case, regeneration always has a lower economic impact than desalination of seawater, one of the main options for improving availability.


Un dels altres obstacles a superar per incrementar la implementació de la reutilització d’aigua és incrementar el coneixement sobre el comportament i toxicitat dels contaminants presents en l’aigua residual. L’aigua residual és el destí d’un gran nombre de compostos (fàrmacs, pesticides, drogues d’abús, metabòlits, etc.), metalls pesants i substàncies derivades de l’activitat humana.

Environmental impact

The environmental impacts from the implementation of regeneration and reuse schemes need to be considered. In some environmental categories (CO2 emissions) these schemes will necessarily involve negative impacts that are expected to be offset by the benefits, mainly the availability of water, derived from their implementation. Life cycle analysis (LCA), cost cycle (LCC) and water footprint analysis methodologies can quantify these impacts but are complex methodologies that require very specific information.

Trace organic compounds (TrOCs)

Referring to trace organic compounds (TrOCs), although the concentrations at which they are found are usually very low and the effects of exposure are usually long-term, there is still a great deal of ignorance about many related issues. Its management: its presence in wastewater, effective treatment systems for its elimination, the impact on human health resulting from long-term exposure, etc.

Audience acceptation

The perception of wastewater, and consequently its derivation, as a vector of disease transmission is deeply embedded in the human mind-set. Most studies highlight the need to involve citizens from the outset in regeneration and reuse projects.

Low volume of regenerated water in Catalonia: 32.11 hm3/year in 2017 and with peaks of 54 hm3/year in 2008.

– Water data in Catalonia –