A campaign to encourage householders and businesses to install “rain gardens” to help reduce flooding has been launched by the Scottish Green Infrastructure Forum (SGIF).

The aim of the project, 10,000 Raingardens for Scotland, is to map Scotland’s existing rain gardens and increase their addition in new developments and existing homes.

Rain gardens are areas of vegetation that catch rain water and then release it very slowly, which helps reduce the severity and likelihood of flooding.

These can be anything from small areas of flowers, trees and bushes in a car park or at the roadside, or a planter box connected to a roof down-pipe that funnels rain from a building’s roof to a larger inter-connected green drainage scheme running through a housing development.

Green roofs and green walls can be used in the same manner. Neil MacLean, chairman of SGIF said: “Scotland has a fantastic environment and we should all be proud of it. However, many towns and cities need a little help to improve river and water quality, and the biodiversity value of limited green spaces.

“With our climate changing, the risk of flooding is increasing. By introducing pockets of valuable, colourful and attractive vegetation we aim to reduce the risk of flooding and improve the water quality of our rivers.”

By installing several rain gardens over small areas, marked improvement to water quality and biodiversity can be made, claim SGIF, as well as flood risk reduced. The campaign, which includes an online toolkit to help people create their own raingarden, will showcase their benefits.

Mr MacLean said: “Whether you are a chief executive of a company, an employee or a household resident you can create a rain garden. Not only will this contribute to reducing the severity and likelihood of flooding but, at the same time, you can enhance your surroundings and provide colourful, vibrant and pleasant areas.”

Rain gardens help reduce pollution by filtering out contaminants collected in rainwater before it enters streams and rivers. They also filter air, provide habitats for wildlife and reduce noise pollution.

In August, the Royal Botanic Garden Edinburgh (RBGE) was able to make use of its experimental rain garden after significant rainfall. A response to rapid climate change and more frequent rainfall, an existing garden was adapted to meet the challenge of heavy rain and gardeners and researchers subsequently monitored its impact.

Following downpours earlier in the month, the garden, which features a range of carefully selected plants in a special mix of soil, compost, sand and gravel, successfully absorbed the excess water that fell, reducing floods on nearby paths and capturing rainwater for the benefit of the plants that grow in abundance nearby.

RBGE’s herbaceous supervisor Kirsty Wilson said: “Raingarden creation is great news for plant lovers. Lawns are simply not as effective at soaking up or trapping excess water. Replacing hard surfaces and grass areas with a mixed selection of herbaceous perennials and shrubs can capture water run-off and increase the wildlife and habitat value of the area.

“The mix of plants we have chosen will encourage a great diversity of wildlife, providing nectar sources for insects and bees in the summer, and we will leave the stems of the perennials and grasses standing over winter to provide a home for invertebrates and food for seed-eating birds.”

Created in collaboration with experts from the Water Academy at Edinburgh’s Heriot-Watt University, the raingarden was being used as a living laboratory to learn more about the trees, shrubs and wildflowers that are best able to cope with occasional temporary flooding, and can help to naturally reduce waterlogging, as well as plants that can withstand other extreme weather events such as drought.

Dr David Kelly, whose research focuses on finding nature-based solutions to rainwater flooding problems, said: “The RBGE has witnessed changing weather patterns that reflect how climate change is impacting Scotland. Longer dry periods followed by heavy downpours have proved particularly problematic in terms of maintaining plant health and avoiding localised flooding issues.

“This experimental garden will be helpful in understanding and planning future site management strategies for coping with an unpredictable, changing climate and ensuring uninterrupted provision of the important public amenity at RBGE.”