Water reuse plan in the Barcelona Metropolitan Area
An outstanding example of planned water reuse is the case of the Metropolitan Area of Barcelona, probably one the largest reuse projects in the world with a visionary water resource management solution. In the Barcelona Metropolitan Area, the traditional water resources from the Llobregat and Ter rivers have been unable of meeting the water demand during prolonged drought periods. Furthermore, with the objective of avoiding the overexploitation of underground water resources, which caused the saline intrusion in aquifers, and overcoming the superficial waters ecological deficit, it was concluded that the most sustainable solution was to implement water reclamation and reuse. The water reclamation plant (WRP) of Baix Llobregat enhances the secondary effluent through several treatment plans, according to the quality requested for the different uses.
Ecological flows and wetlands maintenance
Up to 2,0m3/s of reclaimed water is employed for ecological purposes, as Llobregat river ecological flows maintenance (1,5m3/s) or the river basin aquifer recharge (0,5m3/s). Additional 0,4m3/s are used for maintaining the natural wetlands of the Llobregat River Delta.
Water reuse for irrigation
The distribution system of reclaimed water also provides 0,75m3/s of water for agricultural irrigation, which is obtained after treating it with a reverse electrodialysis satellite system (EDR) to remove the excess of salinity.
Aquifer artificial recharge to create a hydraulic barrier against saline intrusion
The direct aquifer recharge with reclaimed water acts as a hydraulic barrier, enabling a reduction of saline intrusion in a strategic aquifer for Barcelona supply, which has historically been overexploited. The reclaimed water, after the above mentioned additional process of UF, RO and UV disinfection. The injection of 3.500m3/day began in March of 2007. An estimated total volume of 244.00m3 was already being injected at the end of that year.
Montjuïc reclaimed water distribution systems for green and industrial areas
A reclaimed water distribution network for municipal and industrial users in the Montjuïc area was designed and constructed in 2010. It has been calculated that reclaimed water demand is 0,025m3/s for green areas irrigation and 0,08m3/s for industrial proposes.