seasonal tariffs can be very effective in providing higher incentives for saving water in periods with high scarcity increasingblock tariffs on the other hand which foresee elevated charges above a certain level can be an effective way of reducing consumption from users with very high demand wateco in any case price structures need to be volumetric with low fixed charges in order to provide incentives for reducing water consumption water metering is usually a precondition for effective pricing systems roth lallana et al