RFI - Attachment 7 - Updated SWMP

5. Establishment and Operational Phase
   Management
5.1         Establishment
Experience shows that the critical periods in the life of WSUD vegetated stormwater systems are the
construction and establishment phases. The timing and approach to these systems must be carefully
considered to ensure successful establishment and long-term performance. Bioretention systems are now
common stormwater treatment devices for new urban developments in Southeast Queensland. Successful
construction and allowing adequate time for the systems to establish is critical to their long-term
performance and function. Construction of the system is also linked to having suitable bioretention designs
in place to ensure, civil contractors have appropriate plans to construct to. Applying due care in the design
and construction phase will ensure the function of the system whilst also keeping on-going maintenance to
a minimum. It is highly recommended that the constructed activities be completed in accordance with the
Construction and Establishment Guidelines: Swales, Bioretention Systems and Wetlands (Apr 2010). This will
require a sacrificial turf layer to be installed to protect the filter media from the building phase. It is likely
that a low height retaining wall will be used on some or all sides of the bio basin to minimise the footprint
of the bio basin and maximise the outdoor use area for students. As the walls will be low in height, they will
be ultimately screened from view by the vegetation planted in the bio basin filter media.


5.2        Operational
It is not proposed for water quality monitoring of the bioretention system to be undertaken during the
operational phase of its life. The “Maintaining Vegetated Asset” guideline highlights that water quality
monitoring is not recommended to determine the performance of every vegetated stormwater asset, as it
is a specialized field that is complex and costly. In line with this guideline the on-going monitoring of water
quality from this device is not considered necessary considering the small size of the development.

The bioretention system will remain the responsibility of the landholder, who as the asset custodian, will be
responsible for the on-going maintenance of the water quality device. Maintenance for the bioretention
basin may involve the following:

      1.   Scheduled inspections;

      2.   Removal of noxious plants or weeds;

      3.   Maintaining the desired vegetation;

      4.   Repairing erosion;

      5.   Unblocking inlets and outlets;

      6.   Removing litter and debris;

      7.   Managing algal or moss growth;

      8.   Maintaining the permeability of the filtration.

Operations and maintenance should be conducted in accordance with the Maintaining Vegetated Stormwater
Assets (Feb 2012) guideline.




21-0211SMP01V1 | Stormwater Management Plan | Good Shepherd Lutheran College Arts Centre                 Page 16