Barcelona will force the reuse of shower water for toilets in new buildings. The City Council estimates that a household of four people uses about 200 liters of gray water per day.
The new regulations will establish the technical criteria to use this gray water with "quality guarantee and in a sustainable manner" The council has assured that this use is "profitable" in buildings with more than 16 homes or that have a minimum annual water consumption of 500 cubic meters. The investment to install this system "is minimal" and that it is recovered quickly.