Request for Minor Change to OPW

 10 April 2024                                                                                Our ref: Insert Internal file reference name
                                                                                                                           File ref: 8265
                                                                                                             [email protected]




 Noosa Council
 PO Box 141
 Tewantin QLD 4565


 Attention: Morgan Gaffney

 Dear Morgan
 170 & 174 Eumundi Noosa Rd, Noosaville
 Request for Minor Change to Operational Works Approval OPW22/0052

 Our client BDH Properties Pty Ltd wishes to request a Minor Change to Operational Works Approval OPW22/0052.
 As previously advised, an existing 225mm diameter drainage pipe discharging to Eumundi Noosa Rd was recently discovered
 that neither our client nor their previous engineers were aware of. Potholing, CCTV and survey have all been undertaken to
 confirm its location and condition. A review of old google street view imagery confirms that this pipe was the primary discharge
 point for stormwater flows coming from the old car wash that previously occupied the site before it was demolished in 2016.
 Given this finding, it is now our clients preference to amend the design such that minor flows are directed to Eumundi – Noosa
 Rd via this pipe (with the addition of kerb outlets for roof water) and allow excess runoff in major storm events to flow to the rear
 (as has always been the case), in lieu of filling the site to direct overland flow to the street (as per the current OPW approved
 drawings). This will significantly reduce the height of the proposed retaining walls (at the rear of the new lot) and significantly
 reduce the quantity of the imported fill. Some lower height retaining walls and imported fill will still be required to ensure that the
 site achieves fall to the northeast corner.
 Please refer to the attached sketch for details of the revised proposal. Essentially it involves the following:
 •    Raising the back of the site to achieve 1 in 200 fall to both the north and east (so that the low point is in the NE corner of
      the site).
 •    Installing a new field entry pit in the NE corner of the site to capture existing overland flows (and provide a connection point
      for all future overland flows) and connect this to the end of the existing pipe via a new 225-diameter pipe and field entry pit.
      Note that this pipe will have 450mm minimum cover as per QUDM recommendations.
 •    Using the existing 225 diameter pipe to provide the primary connection point for the discharge of all overland flow.
 •    Installing new kerb adaptors with connecting RHS’s to provide for roofwater discharge for any future development.
 Calculations are attached which demonstrate that this revised proposal will result in less runoff flowing to the rear than all
 previous development scenarios i.e.:
 •    The current approved design.
 •    The existing situation, and
 •    The previous situation when the businesses were operating (before demolition in 2016).


 Please contact Peter Mathers should you have any queries.




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