Where is all the water?


Having lived in the North of England and more recently Ireland, two things they have in common is the large amount of rain fall; the North of England has, on average, 160 days of rain per year and the east coast of Ireland has 162. Ok, so far so wet, but why does this matter in the context of mains water supplies? Primarily because the average Joe on the street cannot make the connection between high levels of rainfall and low levels of mains water in the summer months i.e. if it rains so much why can’t we collect the water in reservoirs for the summer months? Clearly that makes sense, however we need to dig a little deeper.


The majority of rainwater, annually, in the UK, is absorbed into the ground, with the remnants making its way into rivers and streams. Only a certain percentage can be stored in reservoirs (natural or man-made). Clearly when reservoirs are at maximum capacity 100% of remaining water heads into the sea, via rivers. So because the storage capacity is finite, the water at that point is surplus.


The issue of water shortage in the UK came to a head across particularly dry winters, most recently the winters of 2010-11 & 2011-2012, which led to ‘hosepipe bans’ i.e. water use restrictions.


So we can take as a given the finite amount of water reserved in reservoirs; unless significant money is spent on increasing capacity we can expect water use restrictions right? Wrong. What should be done is significant improvement in the transportation of mains water from treatment plants (drinking water / mains water treatment plants) to peoples’ homes and businesses – 22% of mains water is lost every year between treatment plants and end users in the UK. Some would argue what is the point of increasing capacity if nearly a quarter of the water is lost?


Many EU countries face the same, if not worse, losses;


Estimated Percentage of  Mains Water Losses per Country 2013






Losses (%)
















GMR Data 2014


In the UK the group of water companies that provide water and waste water services collectively input £25bn ($42bn) into services in the 5 years to April 2014. The money is typically spent on the day to day running costs of supplying drinking water and taking away and treating wastewater. The funds are also put to building new assets such as treatment works, mains and sewers and making improvements to existing infrastructure.


In Ireland the long awaited water meter roll out is well under way with aim of generating additional income to improve existing water infrastructure.


Will this investment be enough to reduce annual water losses? It will interesting to see if the amount of mains water lost is decreased, across these two territories, or if, as suspected, the same amounts of water is lost as today. It remains to be seen.