RFI - Attachment D - Callaghan and Toth IR response

Callaghan &
Callaghan & Toth
             Toth Consulting
                  ConsultingEngineers
                             EngineersPty
                                       PtyLtd
                                           Ltd
ABNNo.
ACN  No.140292324
         45140292324

6/41 Sunshine
1.16/90
P.O
              BeachStreet
         Goodchap   Road Noosa Junction
                          Noosaville                                                                      Callaghan & Toth
P.OBox
     Box2035
          2305Noosa
               NoosaHeads 4567
                      Heads 4567
www.callaghanandtoth.com.au
www.callaghanandtoth.com.au
                                                                                        Civil, Environmental & Hydraulic Engineers
Ph: 07-54749081 Fax 07 54749041
Ph: 07 5474 9081 Fax: 07 54749041




 27th July 2020


 Mitch Turner
 Design Coordinator
 Noosa Council
 Via Email: [email protected]}



 Dear Mitch

 RE:            Response to Information Request – MCU20/0013 – Hinterland Playground, Cooroy
                Items 15, 17 to 23

 In response to Council’s Information Request letter dated 11th March 2020, detailing further information required to
 assess the application MCU20/0013, the following responses are offered below.

 ISSUE:         Frog Pond water quality issues.

 Item 15:       Revise the design for the management of the external urban catchment which flows through the site
                so that recreation and access is consistent with the anticipated water quality. It is suggested that a
                densely vegetated ephemeral swale (which restricts access and is free-draining, is a more
                appropriate outcome.

 In response to the above Item 15 the following information is offered:

                It is agreed that the external water catchment requires treatment if the frog pond has primary contact. As
                such the frog pond design has been amended to be a densely planted swale that does not hold water and
                flows directly to Cooroy Creek. The dense planting will stop the swale being used by playground users.
                Signage is recommended to be installed to ensure the playground users are aware that the water when
                flowing through the swale is not suitable for contact.

                In regards to treatment of the upstream catchment (part of the Cooroy township) flowing through the site, it
                is estimated that approximately a 2.2 hectare area of road reserve and Commercial areas flows into the
                southern end of the playground site and this stormwater will flows through the Frog Pond Precinct of the
                playground.

                These stormwater flows would require a treatment system to treat litter, sediment and nutrients to ensure
                that the water quality in the Frog Pond Precinct is suitable for the proposed use i.e. primary contact; if the
                frog pond precinct is be developed in the future.

                There is an opportunity for Council to construct a biobasin within the area identified as Catchment 7,
                (approximate surface area of 225m2 – this area would need to be determined during detailed design) with
                an inlet GPT to treat this stormwater runoff in the road reserve of Maple Street in the location shown below.
                The development of this biobasin is outside the budget for the playground project, and as such is
                considered to be a future stage of works and part of a larger commitment by Council to improve the quality
                of stormwater flows from the Cooroy township.




     X:\JOBS\CT Projects in progress\2001 env reports for cooroy playground
     carparks\Correspondence\Applications\MCU\ResponseLetter_MCU20_0013_Playground_C&Tresponse_July2020.doc
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