Leakage is one of the biggest problems in water distribution networks (WDNs), even for the developed countries, as it has substantial technical and financial impacts. It is difficult to avoid the leakage in WDNs, but it must somehow be minimized. This paper presents a case study, in which a detailed field survey was conducted for the selected part of the network of Sharjah, United Arab Emirates to evaluate the amount of leakage in WDN. Two distinct field surveys were conducted during both day and nighttime to assess the leakage, as the amount of leakage varies between these two periods. Mass conservation approach (water balance approach) was adopted for the selected small network to analyze the field data. The results showed that the leakage percentages were found to be of about 14.9 in the day and 28.6% in the nighttime.