If the government insists on the need for a million or so new houses in the South East of England, have we considered harvesting the rainfall that falls on these roofs?
Let's persuade the politicians to make it a planning requirement that every new building is provided with its own rainwater storage tank and simple filters buried under the lawn. With a small pump and a header tank in the attic, this water could be used for toilets, car washing and gardens.
A odest 0m 2 roof with just 700mm annual rainfall yields over 40m 3 a year. Multiply that by 1M and do the same thing for commercial and industrial buildings and you have a lot of water. It would cost at the beginning but the owners would save on their water bills and it would be a lot less power hungry than desalination.
Jim Patterson (M), 122 Desswood Place, Aberdeen, AB15 4DQ