Appendix D - Civil Engineering Report

4 Sewerage Reticulation

4.1     Existing Infrastructure

A review of the DBYD data has revealed the location of existing sewerage reticulation within the Trading Post
Road and Prospect Place road reserves to the south of the subject site.

It is understood that an additional DN160mm PE sewerage main is located within an existing easement which
runs along the subject site’s eastern boundary.         This sewer grades to the north and joins the existing
sewerage reticulation network to the east of the subject site.

The design documentation for the existing Palm Lake Resort stages is included within Appendix E with the
DBYD data included within Appendix D.


4.2     Proposed Demand

The demands on the existing sewer infrastructure were established using the methods described in SEQ
WS&S D&C Code.                 These demands were used to determine the consumption rates for the proposed
development. The sewer demand factors and flow parameters have been taken from Table 10 and Table
A17, respectively, to determine the consumption rates for the proposed development.

The results are presented in Table 4.1 below.

Table 4.1: Residential Sewerage Demands (Palm Lake Resort, Cooroy – Stage 6 Only)

                            Design Parameter                                Stage 3 Sewerage Values
 Area of Land                                              0.5796 Hectare
 Development Type                                          Multiple Housing – Type 3 Retirement and Special Needs
 ET                                                        10
 EP/ET Conversion factor                                   2.7
 EP                                                        27 EP
 Average Dry Weather Flow (ADWF)                           210 L/EP/Day
                    -1.05
 C2 (C2= 4.7 x EP       )                                  3.33
 ADWF                                                      5.670kL/day or 0.066L/sec
 PDWF (C2x ADWF)                                           18.853kL/day or 0.218L/sec
 PWWF (5 x ADWF)                                           28.350kL/day or 0.328L/sec
 Design Flow                                               0.328L/sec

Based on the above assessment it is envisaged that the proposed development will place a demand of
0.328L/sec during PWWF on the downstream sewerage network.

Engineering services layouts detailing the proposed sewerage infrastructure is included in Appendix C.




Palm Lake Resort, Cooroy – Stage 6 – Engineering Services Report                                      Page 11 of 21
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