Sunday, 9 August 2009

Article on Rain Gardens

I've just had a piece published in the local magazine about rain gardens. The gist of it was:
"We’re all aware of the village roads flooding after heavy storms and we’re constantly being told of climate change and its consequences.
You may not know about last autumn’s change in planning regulations, which means that anyone paving more than five square metres of front garden has to do so in a way that prevents rainwater running off onto the highway and, therefore, into the storm water drains. Estate and property developers now have to give consideration to rainwater management, including using SUDS (Sustainable Urban Drainage Systems) to minimise the effects of rainwater during heavy downpours.
The intention of these new planning measures is to have as much rainwater as possible returned into the ground, where it can be soaked up and used by plants before naturally returning to brooks, streams and rivers. This allows the water to move in a delayed, slowed and cleaned manner, instead of as a deluge carrying pollutants from hard surfaces into the drainage system.
(You may think that this is only a problem for the cities, but consider the following small calculation. The population of the village is 2116; assuming an average of 4 people per household this gives 529 dwellings; if they are, on average, similar “roofprints” to my house, the rainwater falling on the village's roofs during a 2-hour heavy storm amounts to about 350,000 gallons (just over 1.5 million litres) – or enough to fill a 25m swimming pool 3 times over! OK, many dwellings will have soakaways instead of pouring this into the drainage system, but just imagine how much more water falls on roads, paths, drives, car parks, ...)
Whilst this new emphasis is a positive step, it still treats rainwater as a problem to be “managed”. Many people are now thinking differently, with rainwater being regarded as a resource. The established use of water butts connected to downpipes via diverters for use in the garden is increasing in popularity, although many of you will know how quickly a water butt is filled in a storm, still leaving the excess to flood into the drainage system. Some people have invested in larger rainwater “harvesting” systems, such as underground storage tanks beneath permeable-paved drives, although these are very expensive, and complex to install.
In their book “Rain Gardens” (Timber Press, 2007), Sheffield University’s Nigel Dunnett and Andy Clayden describe new concepts that combine environmental benefits and aesthetics where rainwater is not seen purely as a resource or as a problem, but is instead a visible, celebrated part of our gardens."

You can see a rain garden I recently designed here.

No comments:

Post a Comment