Is the New Oil, Rain Water?

In the UK, there are still homes that are recovering from the summer floods of last year. However, almost 50% of all English and Welsh households are in areas where a sufficient water supply is still a problem.

Water companies are finding it difficult to meet the increasing demand, particularly in the south of England. After the very wet summers of 2007 and 2008 many householders will have probably forgotten the low rainfall and drought in 2006, or more importantly how dry winters have adversely affected water reservoirs.

Water has historically been a low cost commodity in the UK. We take five minute power showers (using 100 litres); we soak in a full bath (100 litres) and we run washing machines half full (70 to 120 litres). We use a power washer to ensure a moss free drive and leave the garden irrigation system on for hours (1000 litres per hour) in search of a perfect lawn. We don't even think how valuable water is, or even where it comes from, yet commentators state that water - and especially our natural resource - rainwater, is now the new oil.

Water Consumption in the UK.

Average water consumption currently stands at a staggering 160 litres per person, per day. The Code for Sustainable Homes aims to bring this down to 80 litres. How can we reduce this figure? Quite simply, we must all alter our behaviour and use less water.

Rainwater harvesting can help us do this. Water efficient appliances such as slow-flow taps and shower heads and smaller baths to reduce water use are making inroads. However there can be consumer resistance to such solutions and there are stories of such appliances in eco-homes being removed once the owner has moved in. If, however, changing our behaviour and using water efficient appliances can be combined with using rain gathered from roofs, whether this is for domestic or commercial use, then we can achieve lower mains water consumption.

With the following, the government position is now clear:

a) The Code for Sustainable Homes requires social housing to meet level 3, reducing mains water consumption to 85 litres per person per day by using rainwater harvesting and water efficient appliances. At present, for the private sector, this is not required by law, however every new build will have to be given a rating, even if it is nil.

b) Building Regulations Part G will change in October 2009 to enforce a limit of 125 litres mains water consumption per head per day in new-builds.

c) Applications with rainwater harvesting will be given priority planning permission by Councils.

d) Flood Attenuation. Planners now encourage and impose rainwater harvesting to alleviate flood threats.

e) Businesses can benefit from the Enhanced Capital Allowance: 100% of material and installation costs of rainwater harvesting systems registered on Water Technology List can be offset against tax liability.

f) New legislation will give water boards greater hosepipe ban powers during water shortages. Hosepipes will be prohibited for watering the garden and outdoor cleaning as well as for topping up hot tubs, decorative ponds and swimming pools.

g) At any time DEFRA can impose even more stringent drought restrictions.

h) British Standard 8515 came out in February 2009 on installation of rainwater harvesting.

Rainwater harvesting systems can be easily installed by a competent plumber. It's cheaper and easier to install a rainwater harvesting system in new-builds or major renovation projects. However installation isn't complicated and can be done by a builder, or plumber, without specialist knowledge. In a newbuild, depending upon the size of the tank and the type of mains back up accessory chosen, the cost of equipment for a three to four bedroom house typically ranges between £2000 and £3000. In a retrofit, however, installation costs would be another £1000-£2000 because it can involve extra equipment or manpower.

Plumbers must make sure that, when any mains back up device is included, there is an air break to prevent any cross contamination. Some rainwater harvesting suppliers now provide mains back up kits where this air break is taken care of. Also any pipe-work must have clear identification as to whether it is mains or rainwater.

Because of Britain's reputation for a wet and gloomy climate it's taking time to convince consumers and tradesmen that we really do need to save water. By using rainwater constructively we can save around 50% of mains water consumption. Water bills can be considerably reduced in regions where water rates are high already.