Attachment C - Engineering Technical Note · 132008.1128.02

WATER & WASTEWATER NETWORK INVESTIGATION | BLUE CARE




3.5          Internal Water Network Assessment
Network pressures modelled within the proposed network under Peak Hour (PH) and Fire Flow (FF) conditions during the 2016
and 2036 planning horizons are shown in Table 3-2.


Table 3-2: Blue Care Development Network Pressures

                                     Minimum PH                    Maximum PH                Residential FF               Commercial FF
      Planning Horizon
                                      Pressure                      Pressure                Residual Pressure            Residual Pressure
             2016                       37.14 m                      74.73 m                     20.84 m                          14.67 m
             2036                       35.36 m                      74.67 m                     18.37 m                          12.39 m
Note:     1) Fire Flow demand of 15 L/s for 2 hrs applied with PH demand in accordance with SEQ Code for residential land use.
          2) Fire Flow demand of 30 L/s for 4 hrs applied with PH demand in accordance with SEQ Code for commercial land use

Water network modelling of the site demonstrates a minimum PH service pressure of approximately 35.36 m, which is above
the required minimum of 22 m. The maximum pressure identified, 74.73 m exceeds the desired maximum pressure of 55 m. It is
noted that there are numerous nodes exceeding the desired maximum pressure throughout the existing DMA. The minimum fire
flow pressure identified was 12.39 m, which is above the 12 m minimum pressure required.


3.6          Water Network Assessment
The external network within the VLSNR DMA was assessed for Peak Hour and Fire Flow scenarios under existing and
developed conditions. The minimum network pressures for Peak Hour conditions during the 2016 and 2036 planning horizons
are shown in Table 3-3.


Table 3-3: Viewland Sunrise DMA Peak Hour Modelling Results

                                                                Existing Conditions                      With Proposed Development
  Planning Horizon            Development EP             Minimum PH                                      Minimum PH               Nodes Failing
                                                                                Nodes Failing
                                                          Pressure                                        Pressure
          2016                        602                   29.27 m                     0                   26.42 m                    0
          2036                        602                   27.54 m                     0                   24.63 m                    0
Note:     1) Minimum Peak Hour Pressure identified at Node ID: 156846;


Water network modelling indicates that the network has sufficient capacity to service PH demands associated with the proposed
development without negatively impacting existing network customers.


Impact assessment on external network conditions was also undertaken for pre and post development fire flow events. As
illustrated within Drawing No. 18-001942-SK203 within Appendix D, assessment of existing network fire flow conditions applied
a commercial fire flow load on node ID 149881 to account for the existing shopping centre demands. A comparison of existing
and developed network conditions is provided in Table 3-4.


Table 3-4: Viewland Sunrise DMA Fire Flow Modelling Results

  Planning                                             Existing Conditions                                With Proposed Development
  Horizon           Development            Min FF        Nodes       Commercial        Nodes        Min FF        Nodes          Commercial   Nodes
                        EP                Pressure       Failing         FF            Failing     Pressure       Failing            FF       Failing
                                                                      Pressure                                                    Pressure
      2016               602                6.89 m          1            3.06 m             2       2.76 m           1            11.51 m           0
      2036               602                4.98 m          1            1.03 m             2       0.33 m           1             9.43 m           0
          Notes:    1) Minimum Peak Hour Pressure at Node ID: 156846;
                    2) Minimum external FF pressures were modelled at worst case Node ID: 5015919
                    2) Existing Commercial Fire Flow Demands applied at Node ID: 149881, see Drawing No. 18-001942-SK203; and
                    3) Residual pressures assessed in accordance with Unitywater DSS (12 m minimum residual Main pressure at flowing hydrant, 6 m
                    elsewhere in mains that have customer connections).




18-001942-WER01                                                                                                                             Page 5