Rain gardening to stop flooding

WWT Washington’s top tips on climate change gardening

Pond
My small pond edged with an area of bog garden (hence the huge Rodgersia) and surrounded with permeable gravel so it can overflow safely

We’ve seen extreme weather this week, with very high temperatures sparking torrential thunderstorms and flash flooding.

To help gardeners cope with the effects of climate change, WWT Washington Wetland Centre is encouraging us to try ‘rain gardening’.

It’s likely that our gardens will need to withstand more periods of drought and heavy rain and the centre’s new Working Wetland Garden, unveiled this week, is demonstrating how to manage these extremes.

The garden was originally exhibited at last year’s RHS Hampton Court Palace Flower Show, designed by Jeni Cairns, where it won a coveted gold medal and Best Show Garden.

Picture; Ian Henderson/WWT
The Working Wetland Garden in place at WWT Washington Wetland Centre. Picture; Ian Henderson/WWT

It assumes a green roof will be impractical, so instead, it channels rainfall off a central roof into a series of recycled troughs filled with gravel and marsh plants. Anyone can do this instead of having your drainpipe pointing directly into your drains.

The troughs filter out dust, leaves, twigs and bird poo. The marsh plants take up some of the water, but after heavy rain, the troughs overspill into a pond surrounded by plants. Some of the water slowly evaporates or transpires away.

The pond can overflow into permeable paving, flower beds, and hollows, all of which allow water to soak away slowly into the ground.

Picture; Pete Morris/WWT
Marginal plants help the water balance of the garden. Picture; Pete Morris/WWT

WWT Washington’s centre manager Gill Pipes said: “The concept is really simple. It’s just a case of holding back rainwater and releasing it slowly. This helps to stop the garden from flooding during heavy rainfall and keeps water reserves back for when it’s dry.

“If your garden slopes downhill, you can even use a series of troughs, channels, and ponds as a slow watering system to regulate water flowing through your garden.

“The fact the pond is rain-fed with clear, clean water helps to attract wildlife. By slowing down water running off your garden you’re also helping your local environment cope with floods and drought too.

“That’s why it’s called the Working Wetland Garden – because it mimics the water-storing properties of Britain’s moorlands and wetlands.”

The Washington garden uses 85 different plant varieties, most of them British natives, including purple loosestrife, flowering rush, greater spearwort, cornflowers, teasels, scabious, foxgloves, meadowsweet, ragged robin, and yellow flag iris.

The Working Wetland garden has been donated to WWT by HSBC as part of its Water Programme.


Getting there

Picture; Ian Henderson/WWT
Water flows down the roof, channelled into troughs. Picture; Ian Henderson/WWT

WWT Washington Wetland Centre is at Pattinson, Washington, Tyne and Wear NE38 8LE, tel 0191 416 5454.

It sits on the north bank of the River Wear, overlooked by Penshaw Monument.

The centre is east of Washington town centre in Pattinson (formerly District 15), four miles from the A1(M), one mile from the A19 and is signposted off the A195, A19, A182, and A1231 Washington Highway.

For more information on the centre, visit www.wwt.org.uk/wetland-centres/washington.

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