|9.1||Pipe Breaks||Total number of pipe breaks per year expressed per km of the water distribution network||breaks/km/yr.|
|10.1||Sewer System Blockages||Total number of blockages per year expressed per km of sewers||blockages/km/yr.|
The number of pipe breaks, relative to the scale of the system, is a measure of the ability of the pipe network to provide a service to customers.
The rate of water pipe breaks can also be seen as a surrogate for the general state of the network, although it reflects operation and maintenance practices too. It must be recognized, however, that highly aggregated reporting can hide the fact that sections of the network may be perpetually failing, whilst much of the remainder is in reasonable condition. Break rates for different materials, diameters or time periods laid can show where breaks are concentrated.
Sewer blockages are, likewise, a measure of the ability of the sewer network to provide a service to customers. Blockages can reflect a number of issues including the effectiveness of routine operations and maintenance activities, the hydraulic performance of the network, and the general condition of the pipes. Bursts include failures on mains, service pipes where they are the Utility’s responsibility, or at joints or fittings that are found by visible signs of water, not through leak detection by Utility staff. Sewer blockages include all blockages or collapses that occur in sewers or drains that are the Utility’s responsibility, whatever action is needed to clear them.