These guidelines provide recommendations, specification information and pro-forma resources to help successfully construct and establish vegetated stormwater management systems such as swales, bioretention systems and wetlands. Getting this stage right is critical to the ongoing success of such systems in terms of their ongoing performance and maintenance needs.
The guidelines give detailed, well illustrated, step by step instructions across the construction and establishment stages.
A key recommendation is that vegetated systems require longer ‘establishment phases’ when compared with built stormwater measures. This longer vegetation establishment period is critical to the proper commissioning of such systems. The guidelines recommend establishment periods well in excess of 6 months (in the best case they should extend across more than one growing season).
Four options for keeping vegetated systems ‘offline’ or ‘online’ during the construction stage are provided, along with descriptions of how the construction and establishment of long term vegetated stormwater systems relates to construction-phase only sediment and erosion control techniques.
Some invaluable certification and compliance tools are provided, including:
- Civil works and landscaping contract requirements;
- ‘As constructed’ drawing requirements; and
- Inspection checklists and sign off forms to help prevent problems arising.
Rectification guidance is given, based on more commonly experienced issues and failures. The guidelines are useful for WSUD designers, landscape contractors, civil contractors, foreman and site supervisors, and parties that commission, assess or sign off on WSUD elements.