‘Just a drop in the ocean’ – WSC downplays considerable water losses

According to these statistics, Kirkop, M’Xlokk, Mgarr, Munxar, Safi, Santa Lucija and Zebbug (Gozo) lost more than a third of the water consumed to leakages in August 2011.

The highest percentage of water leaks was reported in Santa Lucija in Gozo (53%). In Malta the highest water leaks were reported in Mgarr (41%) and Safi (41%). The lowest losses were registered in Birgu (1.3%).

The highest absolute losses were registered in Mellieha (40 cubic metres per hour) and Sliema (37 cubic metres per hour).

Losses in Mellieha amounted to 26% of the water consumed, while in Sliema these accounted to 23%.

A spokesperson for the WSC highlighted the fact that the statistics were compiled in August, which is the time that the leakages are the highest. “Averaged out over a year to include winter, the results would be very different”.

Asked why some localities have much higher rates of water losses the WSC spokesperson explained that this is due different susceptibilities to leakage, for various reasons such as the different conditions of the network, traffic loading and density of connections.

Asked to explain the very high percentage losses (more than a third of the water consumed) in Kirkop, M’Xlokk, Mgarr, Munxar, Safi, Santa Lucija and Zebbug (Gozo), the spokesperson insisted that one has to understand the scale of the problem by not just looking at the percentage, but also at the absolute value.

For example in Sta Lucija (Gozo), the leakage is over 50% but the absolute value is only 3.7 m3 per hour, an amount which he described as “chicken feed.”

“If you know exactly where the leaks are you can repair, but if you have to search for them this costs a lot of resources so it is hardly worth it”.

He also explained that it does not make much sense to calculate leakages as a percentage of total consumption.

“If the few consumers in Santa Lucija were to suddenly stop using our water (for whatever reason) the system would still leak 3.7 cubic metres per hour, but the percentage ‘lost’ would now suddenly go up to 100%.

“If, on the other hand, these few customers were to suddenly increase their consumption drastically, the same 3.7 cu/mt would only become a small percentage loss and the WSC would look much prettier without even having lifted a finger”.

This is why the WSC does not usually measure leakages in percentages as this would be “an easy way to hide poor performance.”

Instead, the WSC prefers to use the internationally recognised Infrastructure Leakage Index. The ILI is defined as the ratio of current annual real losses, to unavoidable annual real losses.

WSC figures show that leakage have been falling steadily from 1,020 m3/hr in 2004, to 482 m3/hr throughout 2009. The total reduction in leakage in 2009 over the preceding year amounts to 125 m3/hr.