Monday, 28 January 2008


Rainfall is becoming less predictable in our changing climate and so an important part of sustainable garden design relates to the way we manage of rainwater.

Hosepipe bans have become a common occurrence in the UK and can last for well over six months in times of drought - whilst flash floods continue to terrorise the nation.

When it rains, water from buildings and hard surfaces is directed through downpipes, drains and gullies into the drainage system. Some downpipes from the roofs of domestic properties are directed into a soak-away and so return to the water table naturally. However, in urban areas the water is taken away into drainage systems.

The current water management system makes our bills more expensive - with the need for constant repairs and new drainage systems to cope with peak rainfall. It also causes groundwater levels drop as the water doesn’t return to the water table, and so we all suffer from water shortages.

The average house roof apparently sheds 45,000 litres of water per year! This means that nearly 25% of the water we currently use could be harvested from our roofs.

The simplest way to capture rainwater is to use diverters on your downpipes and feed this into water butts or rain barrels – but on a large scale this can look unsightly.

A better, but more expensive solution, is the storage of grey water and rainwater in an underground tank. This is a far more practical solution as the water can be pumped directly from the tank to flush toilets, feed the washing machine and irrigate the garden.

These companies are specialists in grey water recycling:

For more information on the science behind grey water recycling check out this site

With careful planning, gardens can be designed to include sustainable solutions for managing rainwater and drought.

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