“…Elimination of leakages, apart from being not technically possible due to their nature [19,24,25], it is also not cost-effective due to diminishing returns (i.e., the more the investment on leakage reduction, the less the additional benefit; see, e.g., [26][27][28][29]). Therefore, water supply agencies seek to determine the economic level of leakages, below which any further investment is not cost-effective (see, e.g., [30][31][32][33]), while applying the appropriate leakage reduction strategies proposed in the international literature.…”