COMMUNITY GARDEN RAINGARDENS
Are there ways your community garden or allotment could use raingardens to help improve water quality and reduce flooding?
We’ve put together this leaflet to show you some ideas which could help your community adapt to the changing climate by slowing down, and using, rainwater.
Currently, rainwater from roofs and hard surfaces (such as roads, pavements and parking) is collected in gutters and drains and flows down into the sewer system. We often have combined sewers, which mean the rainwater, greywater and foul water all go to the same sewer pipe, mixing together and then being treated at the sewage works.
Our climate is changing, with more and more heavy rain showers where a lot of rain falls very quickly. Our sewer system was not built to cope with so much water, and when it rains heavily the rainwater fills up the sewer with nowhere for the water to go, causing flooding. It also causes combined sewer overflow valves to open, and a mixture of foul water, greywater and rainwater to empty into our rivers, causing pollution.
But what can you do about it?
You can help by building raingardens!
Your community garden or allotment is an ideal space to slow down, and use rainwater, which can help reduce flooding and stop dirty water overflowing into our rivers. You may also hear raingardens being called sustainable drainage or SuDS.
Raingardens use plants, soils and the landscape to hold on to rainwater and then slowly release it. They also help reduce the amount of water which gets to the sewer. Some water is taken up by the plants, some finds its way back down into the ground, and some water will evaporate. Raingardens also help clean the water, which may have picked up contaminants from roofs and hard surfaces. Raingardens in community gardens or allotments can also act as rainwater harvesting, allowing you to use the water for growing.
It might not always be possible to do everything, but even small changes help. The image here gives you some ideas, and these are further explained in the glossary. There are also many other sources of information and ideas including information from the RHS on Gardening in a Changing Climate; as well as landscape architects with an interest in sustainable drainage and raingardens who often have interesting websites and blogs.
Why not just build bigger sewers?
We could build bigger sewers, but this is expensive and may not be the best solution. Rainwater is relatively clean and doesn’t need to be sent to a sewage works before it finds its way back to the river. Rainwater
is also the ideal thing to water plants with. Building raingardens also gives other benefits to humans and wildlife.
Raingardens can provide your community group and visitors with beautiful places to sit, walk through and look at. They provide a space for nature, giving insects (including pollinators) and birds a home and food. The plants which grow in raingardens help improve air and water quality. By slowing down the rainwater, and stopping it getting to the sewers so quickly, raingardens help to reduce flooding and protect our rivers from combined sewer overflow.