Y010-01 AAA Stormwater Report · OPW21/0219

AAA DESIGN & DEVELOPMENT PTY LTD
ABN 33 109 041 287
Unit 34, 13 Norval Court
Maroochydore QLD 4558
Tel/Fax.: (07)5479 6747
Mobile: 0422 039 247
Email: [email protected]

23rd June 2022

12 Grosvenor Tce
Noosa Heads Qld 4567

Application No; OPW20/0172                                         Our Ref: Y010-01

In Accordance with the Information Request Dated 3 September 2021.

    1. Please refer to the attached survey plan (Appendix A) of the hard stand area for 12
       Grosvenor Terrace. This provided the basis for the attached engineering drawings
       (Appendix B) demonstrating the runoff direction and corresponding volume calculations
       as requested.

    2. As the attached drawing (Appendix B) shows, the watershed over the existing driveway
       for 12 Grosvenor Terrace can be divided into two distinct catchment areas. The first area
       is defined by CTM1, whereas the water drains towards the existing inlet pit in the North
       East Corner of the property (Indicated by the arrows). The second area is defined by
       CTM2, which flows towards the kerb into the road reserve. The flow calculations in
       Appendix B for ‘CTM2’ determined that even under a major flood (1% AEP) the maximum
       depth at the invert of the kerb will only rise 25mm. The cross fall for driveway of Number
       12 is 150mm (See Attachment A). Also consider the height difference between the
       driveway at Number 14 and Number 12 is an additional 70mm (See Attachment C).
       Hence, waterflow from driveway at number 12 will not top the high point in the driveway
       of number 14 Grosvenor Terrace.

    3. Formal statement;

Based on the evidence stated above, I, Jose David Lesmes Tirado (RPEQ7198), certify the
downstream Driveway at 12 Grosvenor Terrace, Noosa Heads does not impede surface flows for
all events up to and including the 1% AEP to such an extent that flows will not top the highpoint in
the driveway to Number 14 Grosvenor Terrace.

    4. Construction Management Plan
       4.1    The aim is to cut between the existing kerb and bitumen edge to replace the
              original kerb with M3. This will be done along the front boundary of 12 Grosvenor
              Tce.
       4.2    In order to prevent water seepage between the existing bitumen and the kerb, an
              asphalt repair compound will be used to sealed the gap between the bitumen and
              the new kerb (Refer to Appendix B).
       4.3    The traffic management plan will be organised by the owner at 12 Grosvenor
              Tce.


Do not hesitate to contact us, if there are any queries.

Regards

Jose David Lesmes Tirado
BEng Civil, MIEng Aust, RPEQ 7198


                                                 pg. 1