March 27, 2006. Freerain. The well-publicised drought conditions in the south-east, about to lead to the imposition of a hose-pipe ban, has led to a surge in interest amongst gardening enthusiasts and professional groundsmen in technology which pre-dates mains water supplies Rainwater harvesting systems.

Did you know a garden sprinkler can use up to 540 litres of high quality drinking water in an hour?

Rainwater harvesting systems last seen as a mainstream source of domestic water in the UK in the 19th-century have recently been making a strong comeback as a combination of water-shortages and occasional flash-floods lead to developers and Planning Authorities needing to find creative ways of addressing both problems. Now keen gardeners, too, are looking to such systems to see them through what are likely to be widespread and lengthy hosepipe bans.

Full domestic systems typically supply around 50% of a household's water needs by substituting rainwater for mains-water for toilet-flushing purposes. This they do quite simply by capturing the rain that falls on the roof, then storing it in a large underground tank for use as and when required. This has the triple benefit of storing some of the water that might otherwise help to cause flooding, halving the domestic demand on scarce water resources, and saving the energy wasted in bringing water destined for toilet-flushing up to drinking water standards. Larger systems for commercial or public buildings with large roof areas and a high demand for "non-potable" water are particularly cost-effective.

Shockingly, less than 1% of the water treated by public water systems is actually used for drinking and cooking!

Now gardeners and groundsmen are quickly latching-on to this simple but effective solution to their problems given the potential impact on them of a hosepipe ban. Freerain, one of the UK's leading suppliers of commercial and domestic rainwater harvesting systems, report record interest in their equipment, to provide a reliable supply of irrigation water for gardens and sports-grounds. Provided the storage tank is neither connected to, nor topped-up from a mains-water supply, then the substantial quantity of rainwater stored is available for horticultural purposes.

Broadly, intercepting and storing rainwater for "non-potable" use has beneficial knock-on implications for public water supplies, most notably by reducing demand. Roof rainwater used in horticulture is returned to the hydrological cycle via the usual natural processes. The roof areas involved are usually a tiny percentage of the wider catchment recharge areas, and the roof water intercepted would often not otherwise find its way as source of recharge to local aquifers.

www.freerain.co.uk