Bulk_20200728154350 (2)

Noosa Council documents




                         a.     Provide action plan prepared by a suitably qualified and registered engineer to
                                address all issues related to groundwater and Acid Sulfate Soil management for
                                the underground excavation and construction works, particularly during adverse
                                conditions (eg encountering acid sulfate soil, flooding, high water table).
                         b.     Details for the dewatering measures during the excavation and back filling works
                                associated with works below ground level, including identifying any requirement
                                for any silt settlement tank and/or silt separator during the construction, and taking
                                into consideration the potential of adverse weather conditions and high water
                                table.
                 Issue
                 The submitted plans do not indicate any proposed bicycle facilities on the site.
                 Information Required
                 6.      Provide information regarding any proposed bicycle facilities (eg bike racks) on the site.
                 Water Quality
                 Issue
                 Stormwater harvesting
                 Information Required
                 7.      Condition 32 of MCU19/0089 and the MUSIC model submitted with the application
                         require 15kL of roof water harvesting tanks to be provided and plumbed for indoor non-
                         potable and outdoor use. Clarify whether the tanks will be detailed as above-ground
                         tanks with the BA or below ground tanks with this OPW? If above-ground, identify the
                         available space for the tanks and how they will connect to the surface drainage system.
                         If below-ground, provide full details so they can be approved with this OPW application
                         Also, show the integration of the tanks into the landscaping works.
                 Issue
                 Stormwater quality treatment and bioretention design - The site is very level-constrained due
                 to low surface levels and high (tidal) tailwater levels. These constraints are incompatible with
                 the adopted pit-and-pipe approach to conveying runoff to the bioretention basins. The OPW
                 drawings show the issues being exacerbated by lower outlet levels and greater level
                 differences between pavement and bio surface levels than presented at the MCU.
                 Information Required
                 8.      Provide a revised design for the stormwater quality treatment system at the site which
                         addresses the following issues which are inconsistent with the Bioretention Technical
                         Design Guidelines (Water by Design, 2012):
                         a.     Revise the design levels of the bioretention devices such that the controlling level
                                for the saturated zone sits within the transition layer and not at the base of the filter
                                media
                         b.     Revise the design levels of the bioretention devices such that the base of the filter
                                media is above HAT. In the absence of tidal data for Weyba Creek, levels should
                                be based on the secondary port at Munna Pt.
                         c.     Revise the design levels of the bioretention devices such that level differences
                                between the bioretention surface and adjacent pavement is <500mm.
                         d.     Revise the flush grates specified for the bioretention devices for raised grates or
                                domed grates.




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Document Set ID: 21164971
Version: 2, Version Date: 28/07/2020                                                                        Print Date: 28 July 2020, 3:43 PM