AbstractIn a distribution water network, only a small part represents an economical input for the operator organisms and in some cities it has been estimated big losses in the network, according to the International Water Association (IWA). In water distribution network system most of them results of leaks which are presented in storage tanks, and home outlets (Real losses). The unauthorized and unquantified home outlets (Appaent losses) could represent most of physical losses into the water distribution network.In this paper is proposed a simple and economical methodology to quantify the apparent losses and generate a geographical information system (GIS).