20210041 Bottlebrush Ave RECOR RFI Response

            Similarly, Section 7.12 of QUDM provides maximum pipe and HGL grade limits for full
            flowing pipes. A 300mm diameter pipe (the smallest diameter listed) has a maximum
            grade of 20% to ensure flow is controlled to suitable limits. The maximum pipe grade
            within the proposed design is 15.8%, while the maximum HGL grade line is 16.5% for the
            1% AEP storm event. These are both below the recommended maximum grade, therefore
            the design is considered to be appropriate for the site and within acceptable ranges to
            limit damage to stormwater infrastructure.

            Additionally, concrete bulk heads and trench stops have been added to the drainage
            lines to protect the stormwater trenches from scour resulting in potential pipe movement.

            We believe the revised design addresses the requirements of the RFI and should further
            information be required please contact this office.

            Yours faithfully,
            RECOR Pty Ltd


            Prepared by                                        Reviewed by




            Ben Parry                                          Nathan Wagstaff
            Civil Engineer                                     Manager
            BEng (Hons), MIEAust                               BEng (Hons) MIEAust CPEng NER (Civil, Structural) RPEQ




P +61 7 5211 1003          A 37 Mary St, Noosaville Qld 4566   E [email protected]                 recorconsulting.com