IL FAIT BEAU

Sustainable options, green options and renewables - the pressure is on us to do each one of these, and we know we should. However, it all seems so difficult and it is expensive and the return on the investment could be so long. We might not even be alive to see the benefit.

Rainwater harvesting is one of these options and is something we can all understand quite easily. After all, our ancestors were doing it for centuries until mains water arrived, and it is not rocket science. Generally people with gardens have one or two water butts. Rainwater harvesting is just using water butts on a much larger scale and using rainwater for far more than just watering the garden. Half of the 150 litres of water used each day does not have to be mains water of drinking quality. 30% literally goes down the toilet.

By collecting rainwater from our own roofs we could do without half of our mains water needs by using rainwater for all outdoor use, WCs and washing machine. However, if this is to be done effectively, we must allow for a storage tank that is much bigger than our normal 200 litre garden water butt. An average home needs a tank that, depending on the area rainfall and domestic needs, could range from 2000 to over 6000 litres.

Rainwater is best stored underground to keep it fresh and cool, so the hole required, for example, would be 3 metres deep and 2 metres wide. The rainwater is filtered before entering the tank, and then pumped to where it is needed. Rainwater harvesting kits which include everything needed for an average home cost between £2000 to £3000. As with all sustainable options, installation is best done in the context of a new-build or major renovation where installation costs get swallowed up in the overall works. Retrofitting costs centre on digging the hole and altering plumbing to provide a separate supply system to the WCs and washing machine.

Seen purely in pay-back terms, the investment could take 5 to 10 years to recoup and is achieved by lower water bills. Maintenance costs are low.

So how does rainwater harvesting compare with other green options?

Solar water heating via panels on the roof has been around for several years. Ideally you will require between 4 and 5 m2 of south facing roof area for the panels. The system works all year round, though water will need to be further heated with a boiler or immersion heater during the winter months. If a dedicated solar cylinder is not already installed then you will need to replace the existing cylinder, or add a dedicated cylinder with a solar heating coil. The majority of conventional boiler and hot water cylinder systems will work with solar water heating. If the existing boiler is a combination boiler (combi) and there isn't a hot water tank, then a solar hot water system may not be compatible.

Costs for a typical solar water heating system range from £3,000 to £5,000. Hot water heating bills can be reduced by a quarter to a third and the payback period can be less than 10 years. This depends on what fuel is being replaced (saving on electricity will pay back quicker than on gas or oil).

Rainwater Harvesting Limited supplies rainwater harvesting storage tanks, pumps, filters & management systems to households and commercial businesses. Find a large resource of valuable technical information and advice at http://www.rainwaterharvesting.co.uk . Download the invaluable rainwater harvesting tank size calculator from http://www.rainwaterharvesting.co.uk/calculator.php

Article Source: The Benefits of Rainwater Harvesting over Other Sustainable Options