Raingardens are designed to stop excess stormwater, nutrients, rubbish and sediment from polluting our waterways, bays and oceans. They can even be positioned to capture overflow from a rainwater tank.
How do raingardens work
A raingarden lets water collect and settle on the garden surface then soak through the plants and filter media. Rubbish and sediment is trapped on the surface. Nutrients dissolved in the stormwater are used by the plants and toxins stick to the soil. The soil and plant roots work together to naturally filter the water and remove pollutants.
Test the filter media before installation to check it meets standards for hydraulic conductivity and plant growth and holds adequate soil moisture to support the plants.
The image below shows a cross section of a raingarden.
See raingardens in action
This video explains what raingardens do and how they work, and includes some backyard landscaping ideas.