Protect, enhance and work with the natural hydrological conditions of a site.
Effective methods of working within the natural hydrological conditions of a site include:
- Protecting and providing buffer planting alongside watercourses
- Maintaining overland flow paths within the site
- Avoiding large scale earthworks and working with the slope of the site
- Identifying areas of the site that can naturally absorb water (known as ‘soakage’) and using these to absorb stormwater.
Mimic natural systems and processes for stormwater management.
- Consider the use of living roofs and walls for stormwater filtering and transpiration
- Direct stormwater across gardens, vegetated flowpaths, swales and filter strips to reduce the flow, detain, and filter water
- Treat stormwater runoff in bioretention devices or underground detention tanks
- Minimise impervious areas by limiting the building footprint and using permeable surfaces wherever possible.
Address the effects of stormwater as close to the source as possible.
Design the footprint of the building to protect existing soils and vegetation that contribute to stormwater management.
Avoid building materials that contribute toxins, metals and other harmful substances to stormwater runoff.
Using materials that leach contaminants such as zinc or copper may require expensive onsite treatment to remove it.
Retain roof or balcony runoff for reuse in buildings and landscapes.
Use rainwater tanks to water the garden. Rainwater may also be used for washing clothes and flushing the toilet.
Consider the maintenance of stormwater systems at an early stage.
A low maintenance system will save money in the long term.