Reference Document Stormwater Management Plan May 2024 MCU24/0074

metal roofs to be cleaned at site level, and then discharged locally.

The Atlan Hydrochannel is a SQIDEP certified device having treatment efficiency as shown in Table 5-2.

                                                 Table 5-2- Tested Treatment Efficiencies

                                              Pollutant                       Efficiency (%)
                                Total Suspended Solids (kg/yr)                       88
                                   Total Phosphorus (kg/yr)                          69
                                    Total Nitrogen (kg/yr)                           67
                                    Gross Pollutants (kg/yr)                        100

The hydrochannel is proposed to capture and treat runoff from the driveway area. A surface solution is required in
this location due to limited cover and depth to invert of existing downstream drainage pipes.


 5.1.6 Maintenance Requirements
Periodic maintenance and monitoring of stormwater infrastructure proposed for this development should be
carried out to ensure they are operating effectively during the post-construction phase. After the on-maintenance
period, the responsibility for these maintenance activities shall be the body corporate for the site who may appoint
a suitably qualified maintenance contractor or caretaker to undertake these activities.

The field inlet grates, pits and underground pipes shall be inspected for blockage or damage at least 6 monthly or
after significant rainfall event. Any blockages shall be cleared from the system, and damage assessed to determine
if it impacts on the function of the system or may pose a hazard that will require repair.

The bioretention areas shall be maintained following a schedule of routine inspections undertaken after every
significant rainfall event (30mm of rainfall in a 24-hour period) or on a three (3) monthly basis within the first twelve
(12) months and on a six (6) monthly basis thereafter. The inspection shall ensure the proper functioning and
condition of the bioretention area and ensure that the planting and vegetation health is suitably maintained.
Maintenance shall be undertaken in accordance with the inspection checklist from the Healthy Waterways
Technical Design Guidelines for Southeast Queensland. A copy of the maintenance checklist is provided in
Appendix D.

In addition to regular inspections, the first 4 months of establishment of the bioretention areas requires a watering
frequency of:

    i.    Week 1 - 6 - 5 times per week


   ii.    Week 6-10 – 3 times per week


  iii.    Week 11-15 – 2 times per week


After 5 months, watering frequency shall be adjusted based on the local conditions to ensure plants are
maintained in a healthy state.
All proprietary devices are to be maintained in accordance with the manufacturer’s specifications.


     5.2. Construction Stormwater Management

 5.2.1 Erosion and Sediment Control Measures
During construction, it is necessary to manage stormwater run-off to avoid potential contamination of downstream
waterways from sediments and other pollutants from the site. A range of best practice sediment and erosion controls


Project number 20230025                                                                                        Page 11 of 22
File 20230025_Gympie Tce Hotel SWMP, 2023-05-31 Revision 0



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