Any world’s metropolis requires urban public water networks composed by thousands of kilometres of pipelines and various other installations. Such infrastructure ensemble is expected to be in service for rather long periods of time, as it involved decades of costly investments. Anyway, and independently of careful operation and maintenance of such assets, eventually and unavoidable they will decay and will need replacement. This will occur sooner when soil conditions, or operation and maintenance is unfavourable. The paper explores typical and general problems for renewing infrastructure, with examples from specific studies for some Mexican cities and from other countries found in literature. Also mentions usual materials and elements and their life spans under different conditions, along with replacement techniques and probable costs.

The topics, elements and focuses of attention around water infrastructure renewal are broad and varied and must cover the WHY, HOW, WHEN, WHERE, and WITH WHAT money. They range from technical, constructive and diagnosis tasks, to institutional organization, financial and public awareness. As it is impossible to cover everything in a single paper, the present one is a modest intent to give a brief panorama of the state of the art on several of those issues and focuses. The paper underlines and gives recommendations regarding gaps and needs requiring research, as well as the production of more technical papers and discussion forums particularly in Mexico and the Latin America Regions.