Sustainable Drainage Guide
A comprehensive guide to sustainable drainage for homeowners, developers, and communities.
Last updated: 2026-03-27
Sustainable Drainage: A Complete Guide
Why Sustainable Drainage Matters
Traditional drainage pipes rainwater into sewers as fast as possible, causing flooding when sewers overflow, polluting rivers, reducing groundwater, and increasing downstream flood risk. SuDS address all these problems.
The SuDS Management Train
- Prevention: Reduce runoff at source (green roofs, water butts, permeable surfaces)
- Source control: Manage water where rain falls (rain gardens, soakaways)
- Site control: Manage water within the development (swales, detention basins)
- Regional control: Manage water at catchment scale (wetlands, flood storage areas)
Techniques for Homes
- Disconnect downpipes: Direct roof water to a rain garden or water butt
- Permeable driveways: Replace tarmac with permeable paving, gravel, or grass grid
- Rain gardens: Plant a shallow depression to collect and filter runoff
- Green roofs: Retrofit lightweight green roofs on flat-roofed extensions
Techniques for Developments
- Attenuation tanks: Underground storage that releases water slowly
- Bioretention areas: Engineered planting beds that filter and store water
- Detention basins: Dry areas that fill during storms and drain slowly
- Constructed wetlands: Permanent wet areas that clean and store water
Maintenance
- Clear debris from inlets and outlets (quarterly)
- Cut grass and manage vegetation (seasonally)
- Inspect and clean sediment traps (annually)
- Replace gravel or filter media (every 5-10 years)