Page 1 of 17 Increasing block rate tariffs and water conservation: a case study of individually metered dwellings in multi-storey buildings in the Federal District, Brazil. Authors: Patrícia Silva Cáceres; Lúlio Descartes Silva Azevedo; Kaoara Batista de Sá; Daniel Richard Sant’Ana Abstract: We proposed a pilot study in 12 buildings (all individually metered) in order to answer if the water and sewage tariff currently applied in the Federal District (BRAZIL) promotes the rational use of water and if it is effective for any consumption pattern and residential type. For this purpose, the individual consumption rates were analyzed for 36 months and compared to the values that would be charged if there was shared billing for the building (not individualized). As a result, we found that the service provider obtains greater profits with the individualized metering and that, for consumption below the minimum (10m³) it does not promote rational use. 1. INTRODUCTION Law number 11.445 of January 2007 establishes national guidelines for basic sanitation and the federal policy on basic sanitation. This law also provides among its thirteen fundamental principles: universal access to the service; efficiency and economic sustainability; and the adoption of measures to promote responsible water consumption (BRAZIL, 2007). The holder of the responsibility for providing water and sewage services uses its prerogative to delegate the provision of these services to a concessionaire, as well as to delegate regulation and oversight to a regulatory agency, in order to guarantee the proper execution of the concession agreement and the fulfillment of the public interest. The concessionaire is compensated through the tariff paid by the users, determined at the time of the signing of the contract. This tariff is intended to pay for operation, maintenance, technological improvement and profits to the concessionaire (BRAZIL, 2007). In order to be valid, contracts must contain studies that establish technical, economic, and financial feasibility of the services provided. According to the law, one of the objectives of the regulation is "to define tariffs that ensure both economic and financial balance of the contracts and low tariffs, through mechanisms that induce efficiency and effectiveness of services and allow for the social appropriation of productivity gains" (art. 22, IV). Thus, the law establishes that regulatory rules that define the conditions of service provision, in an efficient way, should include: 1) the billing system and the composition of fees and tariffs; 2) the system of readjustments and revisions of rates and tariffs; and 3) the subsidies policy (BRAZIL, 2007). According to article 2, of District Law number 442 of May 1993, which provides the classification of Tariffs for Water and Sewage Services of the Federal District: