An iterative procedure for upgrading water distribution network reliability is proposed by recognizing valve locations. In each iteration, three types of alternatives: (1) an addition of a valve(s) to pipe(s) without a valve; (2) an addition of a parallel pipe to an existing pipe; and (3) an increase in size of newly added pipes, are compared and the best is implemented. The iterative method is continued until no further improvement in reliability is possible, or a desired level of reliability is reached. This method is illustrated through an example taken from literature.