Night flow analysis and MNF calculation in the subarea of Phase ۲ of Mehrgan town, Mashhad, Iran

Leakage in urban water distribution networks is a serious problem due to the shortage of water resources, and this has necessitated planning to reduce leakage in water supply networks and facilities down to the economic level. In this study, the minimum night flow analysis method was adopted to estimate the leakage rate of the distribution network of the subarea of the ۵۰۰۰-m۳ tank in Mehrgan town (Phase ۲), Iran. In this method, the amount of night leakage was first obtained by measuring the inlet flow rate to the network for a month during the hours of minimum consumption (۲ to ۴ AM) and deducting the night consumption of the subscribers, and then, by determining the average zone pressure point and analyzing the data at this point, the night-day factor was determined; by multiplying this factor by the amount of night leakage, the average daily leakage was calculated. The results revealed that the amount of daily network leakage is about ۹۸.۴ m۳ per day.