Donnachadh McCarthy: The Home Ecologist

They're great for the garden – and a lifeline in a flood. So, do you have a water butt yet?

How, for goodness' sake, could we have had a water shortage in the middle of the one of the largest rainfall episodes ever experienced in England?

That's not meant as criticism of the emergency services, or of any of those who worked hard enough to spare the whole of Gloucestershire from having to evacuate. But the flooding of the premises of a single water utility turned a disaster for 15,000 flooded homes into a crisis of survival for the 350,000 people who lost their mains-water supply as a result.

There are many lessons to be learnt from last month's events, not least the need for urgent action to tackle climate change. But we also need to realise how vulnerable households are – especially when their only source of water is the mains supply. The sight of elderly and disabled people searching the streets for water in 21st-century Britain is something that we will hopefully never see again.

It can be prevented. Across the road from my house in south London is a terrace of houses built in the mid-1990s. If you peek over the back fence, you will see a neat row of rain barrels attached to the drainpipe from the rear roof of each house. If the householders suffered the same fate as those in Gloucestershire and Worcestershire, they would not face the same panic. They would be able to boil their rainwater for drinking and have water for cooking and washing. The reason those rain barrels are there is because in 1995, when the planning application was made, I happened to be a councillor on the council's planning committee, and I insisted that a condition be added to the planning consent requiring the developer to install those very rain barrels. I took this further last year when, in my capacity as a public citizen, I successfully forced a change in Southwark Council's planning regulations to require that all new buildings install rain-harvesting systems.

No matter where you live, email your local councillor to ask if they have such regulations in place. If not, ask them to. This would ensure that all residents of new homes in your area would not be in the terrible position people found themselves in July, left without any water at all. In addition, the water companies should ensure that all existing homes are fitted with at least a rain-water barrel.

Of course, we can all take action ourselves. So far this year, my lavatory has used no mains water whatsoever: it is fully supplied by the simple gravity-fed rain harvester on the bathroom roof. Rain harvesting also helps reduce the four million tons of CO2 wasted by the energy used to pump this water through kilometres of leaking pipes. Rain barrels are often on special offer from local councils, DIY stores and water companies. Check their websites, or try www.waterbuttsdirect.co.uk.

Using rainwater will also reduce your water bills if you are metered, making it a triple winner: saving you money, cutting CO2 emissions, and offering precious insurance against your mains-water supply being cut without warning. We can all help ensure that the lessons of this summer's downpour are taken to heart, and that such misery never happens again.

Donnachadh McCarthy works as an eco-auditor and is the author of 'Saving the Planet Without Costing the Earth'. His website is www.3acorns.co.uk

d.mccarthy@independent.co.uk