Relationship between the modes and causes of failure of pipes in the distribution network of Canal de Isabel II in Madrid

A methodology to determine the modes and causes of failure of water supply pipes is presented. The main objective is to understand the relationship between these two variables and to contribute to current knowledge about water main failure phenomena. Sampling and subsequent analysis constitute a direct method for assessing the condition of water mains. It allows for recording of a high number of variables, in order to establish relationships among them. This case study consisted of 4482 pipe breaks recorded in the water supply network of Madrid, Spain, managed by the Canal de Isabel II water utility. Main breaks were equal to 1937, whereas the number of breaks in service connections was of 2545. Sampling was undertaken during the rehabilitation process. In the water mains, the most relevant causes were corrosion, and pressure or unusual operations. Corrosion was linked to holes, and pressure was associated to longitudinal explosive breaks. Within service connections, the most frequent cause of breaks was due to material defects and was associated with a great number of circumferential breaks. Our results will serve as a basis for developing mechanical models, and for contributing to water company efforts to reduce break occurrence.