Response to Information Request - REC13/0015

.
                                                                                           ~
                                                                                       Callaghan & Toth

    1.        SUMMARY

    The key points of this investigation are as follows:


         1.   Runoff from road widening, footpaths and driveway crossovers is to be cleaned of
              nutrients and gross pollutants via a Bioretention Basin and then released to existing to
              the gully.
         2.   The increase in pollutant loads due to the increase in impervious areas is to be
              attenuated.
         3.   Water saving devices for new fixtures are required.
         4.   Stormwater Detention is to be incorporated into the Bioretention Basin to achieve no
              increase in runoff concentration.




    2.        INTRODUCTION

    This report was written as part of an Reconfiguration of a Lot application Information Request
    for Sunshine Coast Regional Council:


              Submit a preliminary Storm water Management Plan (SMP)showing how stormwater
              from the development will be treated to meet current best practice load based reduction
              targets and how peak discharge will be limited to pre-development rates for all events
              from the 1 to 100 year ARI storm events. The preliminary SMP should be designed in
              accordance with the preliminary master as a result of Item 1.


    As such this Stormwater Management Plan (SMP)has been prepared in accordance with the:


         1.   Water Sensitive Design Code in the Noosa Plan; and
         2.   Water Sensitive Urban Design Technical Design Guidelines for South East Queensland,
              published by Health Waterways.

    The site subject to this report is Lot 136 on MCH978 located at 55 Lake MacDonald Drive,
    Cooroy (refer Site Location Plan Figure 1.1).

    This SMP considers the new hardstand areas, including road widening, footpath, driveway
    crossovers, and new roof areas for the proposed 4 lots. This report also aims to demonstrate
    that the proposal complies with relevant codes and guidelines and that the storm water runoff
    will not change the surrounding hydrology.


    A Bioretention basin is required for the site. This device will enable the water quality objectives
    to be achieved. Water minimisation is in accordance with the guidelines.


    The Model for Urban Stormwater Improvement Conceptualization (MUSIC)has been used to
    assess the     suitability of various treatment devices and to model existing and predicted pollution
    export loads and concentrations.




                                                                                                          5
    55 Lake MacDonalld Drive   Stage 1
                               -
                                              SMP Rev I.doc                             May 2013   1225