Appendix F Engineering Report - 14-16 Mary Street, Noosaville - Bounce Hostels 15.6.2018

     ENGINEERING REPORT
     Address:                     14-16 Mary Street, Noosaville
     Applicant/Client:            Bounce Hostels
1.       Background

     Tod Consulting have been engaged to provide technical advice on the impacts of a proposed
     development at 14-16 Mary Street, Noosaville (Lot 3&4 RP 122928). The property is within the flood
     hazard zone and within the Acid Sulphate Soils overlay area

     The site is also traversed by a 450mm diameter truck sewer located approximately 13m from the rear
     boundary. The site currently contains an existing building that is used for retail purposes. The building
     is surrounded by hardstand areas (a combination of compacted gravel and concrete pavements).

     A prelodgement meeting was held with Noosa Council in October 2017. At this meeting Council asked
     that the following engineering issues be addressed with the Material Change of Use development
     application:
         •    Flood – especially in regard to proposed basement car park
         •    Acid Sulphate Soils – Investigation and Management Plan
         •    Stormwater Management
         •    Access and car parking - particularly for service vehicles
         •    Any additional works or treatment in the vicinity of the trunk sewer including advice from
              Unitywater

     The purpose of this report is to address the above issues and provide likely engineering solutions for
     each.

2.       Flood impacts and protection of the basement car park

     A food certificate for the site has been obtained and it confirms that the defined flood level for the site
     is RL2.4 AHD for a 1% AEP Under 2100 Climate Change Conditions. The current levels on the site vary
     from RL 2.0 to RL 2.3 AHD. Preliminary Architectural drawings show proposed floor levels for the hostel
     rooms and facilities at RL 2.7 to provide adequate free board above the defined flood level. The existing
     kerb and channel invert levels in Mary Street at this location are between RL 1.6 and 1.7 AHD with the
     footpath level at RL 1.8 to 1.9 AHD.

     To protect the basement car park from flooding it is proposed to install a proprietary automatic flood
     barrier at the top for the ramp just inside the property boundary. There are several automatic flood gates
     on the market that use the rising flood levels and the associated hydraulic differential to activate the
     barrier and raise it to protect the car park from flood waters. They do not require power or human
     intervention. The flood gate will be located between the perimeter retaining walls that will be used to lift
     the site levels above the defined flood level. Refer architectural elevations and sections for further
     details. The links below are two examples of the type of flood barrier proposed.

     http://floodbreak.com

     https://flowdefence.com.au/



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     17699 - Bounce Hostel, 16 Mary Street Noosaville – Engineering Report – Rev A