The spokesman in this report is misinformed. In most European countries, the wastage of water is rarely more than 10% and I've never known 20%.
I wrote a document in 1998, pointing out exactly this problem:
The distribution of municipal water is a very major source of wastage. All such distribution systems leak, with losses ranging from typically 3 to 10 per cent in most continental European countries. In some cases, losses have been reported of over 25 per cent. The major cause of these losses is the use of iron or reinforced cement pipes with overlapping joints which are sealed with tow. In time, the vibration of traffic, minor seismic activity and expansion and contraction from seasonal water temperature variations will create sufficient movement that the seals are no longer watertight. Even worse, glazed terra cotta pipes are also porous, where the glazing has been damaged: they are also provided in shorter lengths, so that there are more joints per kilometre.
Ideally, all new underground water distribution systems should be made from welded plastic pipes of suitable quality and which would have a typical leak-free lifetime of more than 25 years.
Conservation
It is strongly recommended that all existing pipework dating from more than 10 – 15 years be replaced as rapidly as possible. The cost of this will not be negligible but the savings in water could amount to more than 10,000 tonnes per day, which is far from negligible. There exists a technology which could provide a temporary palliative for the longer stretches of pipe which are particularly leaky and which is neither very costly in materials nor expensive to install. This consists of accessing the pipe through a manhole or a pit every hundred metres. A polyethylene tubing of the same diameter as the inside of the pipe is introduced and the system forces the tubing against the walls of the pipe for the length of the stretch. Obviously, this can only be applied where there is no branching. In places where this system has been installed, it is claimed that leaks have been reduced by over 90 per cent at relatively little cost and with relatively short interruptions of the water supply. Nevertheless, it is emphasised that this method is suitable only as a temporary stop-gap, typically for a maximum of two or three years, while new pipelines are installed.
There is no excuse for nothing having been done in 9 years.
