I have been doing some research into this one.
The last few winters have had lowish rainfall. But this low rainfall has been well within normal variation. In the UK variations by 33% either side of the nominal average are quite common. You handle variation in rainfall by storing water in the wet periods to use in the dry ones. For the South East, about 70% of storage is in underground aquifers, which are hard to expand. That means that any increase in water storage must come from surface reservoirs.
We have had an 11% increase in population in the SE, and much more is expected. The water companies realised this, and have proposed 5 new reservoirs, and extensions to 3 more, to cope. Abingdon reservoir near Oxford, the Clay Hill reservoir near Canterbury, and a huge reservoir at Broad Oak, near Folkestone. There is also Havant Thicket, a £36m project between Havant and Rowlands Castle, and the Lower Severn reservoir, in the Severn Trent Water area. These plans were funded, and placed in their 20-year plans released in 2004.
Not one has been started. ALL these reservoir works have been halted by government intervention, because it is government policy that we should use 20% less water (see the government 'Water Futures' policy document (2008)). If we all use 20% less water, then these reservoirs will not be needed.
I am not sure why we are being required to cut our water consumption. It seems to be associated with a directive from the EU - a “Communication” issued in 2007 by the European Commission (COM (2007) 414 Final) “addressing the challenge of water scarcity and droughts in the European Union”. This requires all member states to plan to 'save water'.
So none of the five reservoirs deemed essential in 2004, all in the south of England, have seen the light of day. And neither have the three reservoir extensions, although one, the Abberton Reservoir enhancement, in Essex, is due to come on-stream in 2014. And this is NOT because the water companies have tried to avoid paying for them - it is because the government is implementing an 'environmental policy' of 'saving water' and has refused permission for ALL the planned reservoirs to go ahead.
I have been complaining to my MP, to DEFRA and to the CCWater customer representative body about this. Water cannot be destroyed - we can save and use as much as we want without harming the water cycle at all. But DEFRA's view is that we are more 'environmentally friendly' if we use less water.
If anyone wants to add to my lone calls into the centre of government for the planned and required reservoirs to be built, it would be greatly appreciated...