Item 11 Appendix E - Stormwater Management Plan-1.0 · MCU22/0094

 20 May 2022


5.5.4 Maintenance

For the initial maintenance of the bioretention basin it is important to remove weeds and debris,
with regular watering until plants are established and actively growing.

Watering is to be undertaken following the construction of the basin at the following frequency:

      •   Week 1 – 6, 5 times/week
      •   Week 6 – 10, 3 times/week
      •   Week 11 – 15, 2 times/week

If there is no rain, each plant should receive 2.5 – 5.0 litres of water per week during establishment
in the first 6 weeks (40mm/week).

Watering requirements to sustain healthy vegetation should be determined during ongoing
maintenance visits.

Detailed establishment techniques can be found in the Water By Design Construction and
Establishment Guidelines.

Inspections are also recommended following large storm events to check for scour and other
damage.

Maintenance of the bioretention basin will include:

      •   Routine inspections of surface profile to identify areas of sediment build-up, scour and
          erosion or clogging of the filter media;
      •   Routine inspection of the overflow pits and under drains for blockages and litter build-up;
      •   Removal of sediment where it is smothering the basin vegetation; and
      •   Repair all basin damage due to scour or erosion by replacement of filter media and
          vegetation.

A Bioretention Basin Maintenance Checklist is attached in Appendix 4.
Detailed maintenance techniques can be found in the Water By Design Maintaining Vegetated
Assets Guideline.

5.6       Construction Phase (Sediment and Erosion Control)

5.6.1 Intent of Erosion and Sediment Control Management Plan

To prevent stormwater contamination (of watercourses) and the release of contaminated
stormwater and wastewater by ensuring compliance with the Environmental Protection Act 1994
and Environmental Protection (Water) Policy 2009.

5.6.2 Implementation Strategy

Establish control measures and best practice approaches to prevent stormwater contamination
and minimise the risk and adverse effects of erosion and sedimentation. All Erosion and Sediment
Control measures must be designed, constructed and maintained in a manner that is
commensurate with the site’s erosion risk.



 Excellence with Economy in Engineering                                                                  13
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