Appendix G Water and Sewer Analysis

                       WATER SUPPLY AND SEWER NETWORK ANALYSIS
Client: Noosa Shire Council                        Location: 62 Lake Macdonald Drive, Cooroy


3.0 SEWER NETWORK ANALYSIS
3.1 Loading

The following values were adopted based on SEQ WS&S D&C Code – Design Criteria (2020) to
calculate the sewer design loading:

   •   Average dry weather flow,   ADWF = 200 L/EP/day*
   •   Peak wet weather flow,      PWWF= 5 x ADWF*

*Assuming RIGSS sewer will be adopted for construction.

The EP for sewer loading is 186 EP. Table 5 shows the development sewer loading based on the
total EP.

                             Table 5 – Development Sewer Loading

                                              Sewer Loading
                       Parameter       L/EP/day             L/s
                         ADWF             200              0.43
                        PWWF             1000              2.15

3.2 Serviceability Requirements

All modelled scenarios were compared to the requirements from the SEQ WS&S D&C Code –
Design Criteria (2020) and design assumptions which included (but are not limited to):

   •   Emergency storage of 6 hours at average dry weather flow (ADWF) for new pump stations
       and 4 hours at ADWF for existing pump stations
   •   Maximum depth of flow for gravity sewer of 75% of pipe diameter
   •   Maximum rising main velocity of 3.0m/s (1-2 m/s preferred)
   •   Duty flow of pump stations to be greater than or equal to PWWF


3.3 Scenarios

The scenarios that were used in the assessment of the sewer network were based on the
Unitywater InfoSWMM model suppled and are listed in Table 6. The 2036 scenarios represent the
design horizon as a 2041 scenario was not provided in the model from Unitywater. The full
development was added to all post-development scenarios.




Covey Associates Pty Ltd                  5                                  Project No: 233467
Consulting Engineers                                                         M23-0030Rpt Iss A