Rain garden planter

 



Above: Juliet Oxborrow, Martin Pett, Jon Gunson and Olivier Sauer.
 
Amid the overall chaos of climate change, different communities will face individual threats. For Lewes, the main challenge may well be the traditional one: various forms of flooding. Floods caused by river and tide are perhaps best dealt with by local and national government, and work carried out since the 2000 event now protects most of the town (though for how long, is anybody's guess). Flash flooding, on the other hand, is a rather more local phenomenon - in an urban environment, it is usually caused by runoff from roofs and tarmac - and its risk may be minimised by local action. 
 
To illustrate this point, Transition Town Lewes have installed a rain garden planter at Trinity Church, Southover, with the cooperation of and financial support from the church authorities. This kind of planter slows down the flow of water from roof to sewer, giving the latter time to cope with a sudden downpour. As a bonus, the plant roots, compost and gravel filter out a certain amount of pollution, which would otherwise travel down the river to the sea, and then end up on your plate the next time you visit your local chippie.
 
"A deep concern about the environment both locally and globally is at the heart of who we are as a Church and we're thrilled with this and the many other projects our Eco team have set in motion to improve our own treatment of God's world."  Rev. Steve Daughtery, Rector, TRINITY Church Lewes.
 
This is, of course, a serious and pragmatic sort of scheme. On the other hand, there is no real reason why you should not have fun with it. You would need plants that can cope with alternate drought and flood, but, chosen with care, these can be wonderfully decorative. The planter can be as basic as you like - but, on the other hand, could be designed to amuse the children, impress the neighbours, or form an essential part of a water garden - which, given that the other problem we face with water is the likelihood of failing aquifers, might not be a bad idea. And incidentally, one of the easiest ways of making your garden more biodiverse is by adding some kind of water feature.
 
With luck, this particular installation will be the first of many. If you are thinking of building one in your own garden, but think the site presents difficulties, be thankful you are not working in a cemetery, on a Grade I listed building...
 
 

 

RAIN GARDEN PLANTER

TRINITY Church and Transition Town Lewes have worked together to create this rain garden planter to show how the risk of surface flooding can be reduced in Lewes using natural methods.

How it works

Rain garden planters are specially designed to receive and filter rainwater from a diverted downpipe. Inside, a waterproof liner contains layers of soil and sand for filtration. Buried in the base, within layer of gravel, a slotted pipe returns the filtered water to the drain or ground. Rain garden planters can rapidly absorb water run-off, reducing the risk of sewer systems being overloaded and, in turn, the potential for surface, or flash, flooding. 


Rain gardens also help to:

  • filter pollutants, such as nitrates, out of water before it returns into ground-water systems (vital for Lewes, which relies on underground aquifers for its drinking water)
  • create natural habitats in urban areas, attracting bees, butterflies and birds
  • raise public awareness of the importance of natural landscaping to manage flood risk.

The plants

Our plants have been carefully chosen to withstand periods of flooding but can also resist drier periods as well. Most here are ornamental cultivars of native species such as:
Ajuga reptans ‘Black Scallop’- Bugle;   Mentha aquatic - Water mint;  Carex ‘Fishers Form’- Sedge Vinca minor ‘Illumination’; Dryopteris filax-mas ‘Cristata’- Male Fern; Lysmachia nummularia ‘aurea’- Golden Creeping Jenny; Fritillaria melegaris  - Snakehead Fritillary