Pipe break data analysis in Emilia-Romagna, Italy, a first step towards effective management of water distribution networks

As part of an effort to reorganize the water services in Italy, this study analyzes several urban water distribution networks in Regione Emilia-Romagna, in Northern Italy. The study focuses on breaks in pipes constituting the network during the years 1994-1997. First, a standard recording format was developed to collect and classify pipe break data and other information in networks with widely different structure and characteristics. Second, data were analyzed to determine the spatial and temporal distribution of breaks in space and time for each network; the yearly and seasonal mean break rates were evaluated for each material, to individuate significant trends in time and non-homogeneities in the break spatial distribution: the break rate was found to increase significantly during the summer in all networks examined. Furthermore, pipe break rates was found to depend inversely on diameter, confirming literature findings. Data analysis by material, tough hindered by the scarcity of data, evidenced widely different break rates; where present, nodular cast iron pipes exhibited the lowest break rate. As to other factors possibly influencing break rates, the study showed a weak positive correlation with precipitation, and no correlation with temperature or traffic levels. It was not possible to establish a quantitative correlation with pipe age because of the lack of data. The study indicated a necessity to standardize the procedures adopted to collect and classify data by the Agencies managing the service. The semiquantitative correlations derived will prove useful in scheduling a timely substitution of the pipes in the water distribution network.