Water utilities evaluate the water distribution system performances by taking various performance indicators into consideration. However, it is necessary to digitize the current network characteristics and to provide hydraulic models, district metered area and pressure management system besides monitoring the water distribution systems by SCADA in order to identify an important part of these indicators. On the other hand, these studies are quite costly for underdeveloped countries including Turkey, so they are projected and applied partially in accordance with the budget of water utilities. Nevertheless, the utilities should control the network performance and make investments by taking the income and expenditure accounts into consideration. In this study, the network performances have been evaluated simply on the basis of the probabilities of exceedance determined with the help of innovative models based on risk calculations of non-revenue water volumes determined by using water supply and accrual amounts of the previous year held by water utilities. As a result, it is seen that the non-revenue water reduction performances of Izmit and Kandira have the highest levels in the evaluation years (2017 and 2018) based on 2010-2016 time period. Korfez has also the highest performance after the above-mentioned districts. On the other hand, the lowest performance occurred in Derince for analysis years. Thanks to the approach suggested in this study, the network performances can be analyzed easily through the data on the previous year water supply and accrual, and thus, future strategies and plans can be identified considering the improvements made.