Department of Environmental Engineering, Faculty of Civil, Planning, and Geo-Engineering. Institut Teknologi Sepuluh Nopember Surabaya 60111, Indonesia.

Email: gregoriusnfn@gmail.com

Reducing water losses in a water supply company is one of the efforts to support sustainable water management so that the quantity of water produced can have a greater benefit value, and ensure the quality of piped drinking water is free from contamination due to leakage. One method to collect water loss problems is to make a detailed water balance so that the challenges and the NRW value can be seen. The challenges faced by Tirta Patria water supply company are the low level of accuracy in the tools used to record the volume of the input system, the lack of data on the speed coefficient of water loss repair, the search for illegal connections have not been carried out, increasing the activity of the calibration and replacing the house connection water meter, making performance coefficients of aged water meters, and performing a minimum night flow analysis. The estimated value of water losses from water balance is 58.91%, with physical losses is 45.59% and commercial losses is 13.32%.