Urban water networks have played a paramount role in the development of human settlements throughout history. Originally designed to supply water, their role has evolved to drainage and, more recently, to gray water reuse. This talk will present a brief overview of the development of urban water networks and highlight their evolution through time. The changes in design rules, data acquisition and exchange standards will be highlighted. Data imperfections will be addressed through examples drawn from the datasets acquired by the consortiums of the STARWARS (STormwAteR and WastewAteR networkS heterogeneous data AI-driven management) and CROQUIS (Collecting, Representing, cOmpleting, merging and Querying heterogeneous and UncertaIn data) projects. Some attempts made in the literature to overcome data limitations will be addressed. Rather than a traditional conclusion, the talk will attempt to incite discussions on possible ways to integrate knowledge and reasoning to address data imperfections.