Storm Water management plan · MCU12/0133.03

Noosa Council documents


                  Bligh Tanner Consulting Engineers                                                                           Page 6
                  Noosa Flexi Learning Centre Stormwater Management Plan
                  August 2012



                  systems ensure water reuse             the reticulated water supply in
                  facilities have no impact on the       accordance with AS/NZS
                  quality of the town mains water.       3500:2003 Plumbing and
                                                         Drainage.
                  Use of natural treatments and          S9.1 & S10.1 Development          The need for natural treatment
                  systems                                complies with the water quality   systems will be minimised by
                  O9 Natural treatment strategies,       standards in Table 2 of the SEQ   preserving the natural hydrology
                  including grass swales and bio-        Regional Plan Implementation      of the site, thereby minimising
                  retention systems, vegetated           Guideline No. 7                   any increase in surface runoff.
                  filtration strips and gross
                  pollutant traps, are used
                  wherever practicable;
                  AND
                  O10 Within the Shire Business
                  Centre, as shown on Map
                  SBC— where necessary,
                  drainage lines are ecologically
                  enhanced to ensure that the
                  water quality polishing functions
                  are of high standard.




                  As per Table 2 of the SEQ Regional Plan Implementation Guideline No. 7, development that
                  is less than 25% impervious is excluded from load-based objectives but is required to
                  capture and manage the first 10 mm of runoff per day from impervious areas.

                  The rationale for this, according to the SEQ Regional Plan Implementation Guideline No. 7 is

                           “Since the load-based reductions are relative to the average pollutant loads in
                           untreated runoff, a higher standard is effectively imposed on low-pollutant-generating
                           development, by requiring pollutants to be removed to unachievable levels.
                           Accordingly, development resulting in no more than six dwellings or 25%
                           imperviousness or less can be addressed through simpler ‘deemed to comply’
                           solutions


                  2.2 Hydrologic Objectives
                  The hydrologic objective for this site is to preserve the natural hydrologic regime of the
                  catchment by avoiding any increase in the volume of surface runoff leaving the site.

                  This would thereby satisfy the Frequent Flow Management Objective outlined in Table 4 of
                  the SEQ Regional Plan Implementation Guideline No. 7, which states that the first 10 m of
                  runoff should be captured and managed (where the total impervious surface is 0% to 40%)
                  management of captured stormwater may include infiltration to native soils (where adverse
                  impacts will not arise).


                  2.3 Water Savings Targets
                  The proposed centre is a Class 9 Commercial Building (under the Building Code of
                  Australia), and therefore the Queensland Development Code Mandatory Part 4.3 Alternative
                  Water Sources – Commercial Buildings applies.

                  Accordingly, the centre must have an alternate water source which provides water for
                  suitable uses.




                                                                                                          Print Date: 2 March 2020, 2:19 PM