The EU Water Framework Directive not only pursues the goal to safeguard waterbodies and clean drinking water by legal means but demands the introduction of economically informed instruments in its Art. 9. So far, Germany had not implemented Art. 9 on the federal level, but has relied on water levies in the Länder (German “states”) for this purpose. This paper explores whether the newly introduced § 6a Wasserhaushaltsgesetz (Federal Water Resource Management Act) has set new standards for the fulfilment of the demands of European Union law by defining the cost recovery principle. It also looks into the problems posed by the merging of two systems for behavioural governance: law and economics – trying to console their different ideas within the interpretation of terms such as “water users” and “water services”.