In drought-prone mediterranean regions like Southern Spain, current water use is not sustainable, and reclaimed water use not economically attractive given farmers have access to well and groundwater use at a low cost or even free of charge. An appropriate water tariff structure could be introduced to create incentive and finance associated water treatment and reclamation costs, particularly in countries where all surface and ground waters are in the public domain and controlled by the regional government. In this context, a water tariff structure can be defined as a fair charge imposed on wastewater operators to cover the costs of providing the water service whilst ensuring that it is affordable (WAREG).