The AMB has set up a number of subsidised pricing systems for both the water cycle and public transport. In the case of water, the rate has a twofold social and ecological purpose, while in public transport there is a range of travel cards available which make it easier for particular groups to use the service.
Water bill subsidies
More information about the subsidy (in Catalan)
More information about social pricing travel cards (in Catalan)
More information about the metropolitan tax (in Catalan)