Burst Detection and Location in Water Distribution Networks

An algorithm for the detection and location of sudden bursts in water distribution networks combining both continuous monitoring of pressure and hydraulic transient computation is presented. The approach is designed for medium and large bursts that are the result of the sudden rupture of the pipe wall or other physical element in the network and are accompanied by the transient pressure wave that propagates throughout the network. The burst-induced transient wave arrival times and magnitudes measured at two or more points are used to find the location of a burst. The wave arrival times and magnitudes are detected using the modified cumulative sum (CUSUM) change detection test. Results of validation on a real network show the potential of the proposed burst detection and location technique to be used in water distribution systems. Introduction The losses in urban water supply system can be divided into two major parts apparent losses and real losses (Lambert, 2003; Morrison, 2004). Apparent losses are due to the unauthorized consumption and meter inaccuracy, whereas real losses include leakage and overflows. Real losses can further be separated into bursts and background leakage. A pipe burst is the rupture of a pipe wall or other element in the network that is usually followed by a large discharge of water. Although the background leakage often is the main contributor to the volumetric loss, the overall costs associated with pipe bursts can be significantly larger and includes the cost of water that is lost, the repair of damaged surrounding infrastructure or flooded properties, customer complaints about interrupted supply, etc. Pipe bursts are relatively frequent in water distribution systems. Since many water supply systems are old and in poor condition, it is practically impossible to prevent pipe failures. Nevertheless, the losses associated with bursts can be reduced by minimising the time of burst detection and location. Although most bursts result in the appearance of water on the ground surface and are detected by customers or water company personnel (passive burst detection), the average location time can be quite long. In Morrison, (2004) the time for awareness and location of a 4 m 3 /hour burst was estimated to be 5 days. Obradovic, (2000) reported burst location times of around 18 hours. Experience from the oil and gas industries shows that the determination of a burst location can be made more efficient and accurate by continuous monitoring of the system. Recent developments in instrumentation and data acquisition have reduced the cost of monitoring systems and made continuous monitoring of water supply systems feasible. However, most burst (leak) detection techniques described in the literature consider single pipelines and cannot be directly applied to a network situation (Misiunas et al., 2003; Silva et al., 1996; Zhang, 2001). In fact, the complicated topology found in water distribution networks requires special attention for burst detection and location methods to be successfully applied.