عنوان مقاله [English]
Management of water demand and modification of consumption patterns are becoming increasingly essential due to the increasingly limited precipitation and the growing population which have led to both severe restrictions on renewable water resources and increasing demands for water in Iran. The most important consumption management measures involve reducing Non-Revenue Water (NRW) and decreasing water losses in the water supply system. Non-revenue water is defined as the difference between the total inflow and the metered consumption in the supply system. The losses may be divided into the two components of apparent and real losses. Achieving reductions in non-revenue water calls for the careful study and evaluation of the operational procedures proposed in each case since reductions will be economical only when accurate and realistic values are considered in water pricing. The present study draws upon the data obtained from non-revenue water projects implemented in District 4 of Tehran Water and Wastewater Company, the measures proposed by the project consultant, and the economic justifications claimed for all the costs associated with the measures to eliminate water losses. The cost of the proposed measures are calculated for two different economic values of water proposed to ensure benefits, and under four different interest rates. Results confirm the profitability of the non-revenue water solutions based on the finished cost of water even at subsidized rates of public funds. However, project profitability will be in question if the economic price of water is assumed to be equivalent to the total trade price of water and if both real and apparent losses are to be reduced.