16-001014-01A (Swmp)

                                       Table 3-6:      Stormwater Detention Basin Concept Details

             Basin Details                                  Northern Basin2                                   Central Basin3
   Detention Volume to 1% AEP
                                                                 1,030m3                                          4,620m3
   Basin Level
   1% AEP Basin WSL (m AHD)                                      RL 100.5                                        RL 101.03
   Minimum Embankment Level (m
                                                                 RL 100.8                                        RL 101.30
   AHD)
   Normal Operating Level (m
                                                          RL 99.1 (Filter Level)                                  RL 99.2
   AHD)
                                                                                                 1.2m x 1.2m Riser Pit at RL 100.45m
   Primary Outlet Pit                            0.9m x 0.9m pit at RL 100.0m AHD
                                                                                                                AHD
   Primary Front Orifice                          2 x 250mm Dia at RL 99.4m AHD                     2 x 400mm at RL 99.6m AHD
   Primary Side Orifice                                            -                                2 x 400mm at RL 99.6m AHD
   Balance Orifice (between pits)                  1 x 300mm Dia at RL 98m AHD                                    -
   Secondary Outlet Pit                          0.9m x 0.9m pit at RL 100.15m AHD                                -
   Outlet Pipe                                       1 x 375mm at RL 98m AHD                        1 x 825mm at RL 98.3m AHD
   Major Overflow Weir
                                                  4m Wide1 Weir at RL 100.4m AHD                  10m Wide1 Weir at RL 100.9m AHD
   (Major Storm Events)
                                    Note: Further Basin Configuration Details are provided in Appendix C
      1
       Width refers to the base width of the weir; refer Calibre Consulting’s Operational Works Drawings within Appendix H for details
                  2
                  For further configuration details of the Northern Basin, refer to Drawing No. 16-001014-415, 416 and 417.
                  3
                      For further configuration details of the Central Basin, refer to Drawing No. 16-001014-402, 409 and 410.

The storage utilised for Stormwater Quality (i.e. the 300mm of temporary extended ponding depth above the bioretention filter media and the
  400mm above the normal operating level in the pond) has not been included in the detention volume. This is considered a conservative
                                                                 assumption.
The following stage-storage discharge relationship provided in Table 3-7 and Table 3-8 was modelled for each detention
basin.

                                 Table 3-7:      Northern Basin Stage Storage Discharge Relationship
                                       Accumulated              Discharge
            Stage (m AHD)                                                          Basin Control/Structure
                                       Storage (m3)               (m3/s)
                   99.4                      0                     0.00            Primary Front Orifice (2 x 250mm Dia)
                   99.5                     70                     0.02
                   99.6                    144                     0.06
                   99.7                    222                     0.11
                   99.8                    306                     0.14
                   99.9                    394                     0.16
                  100.0                    487                     0.18            Primary Outlet Pit (RL 100.0m AHD)
                  100.1                    585                     0.28
                  100.2                    688                     0.35            Secondary Outlet Pit (RL 100.15m AHD)
                  100.3                    796                     0.45
                  100.4                    910                     0.46            Major Overflow Weir (RL 100.4m AHD)
                  100.5                   1,030                    0.70
                  100.6                   1,156                    1.20
                  100.7                   1,287                    1.95
                  100.8                   1,424                    2.92            Top of Embankment (RL 100.8m AHD)




16-001014-01 | STORMWATER MANAGEMENT PLAN (SWMP)                             COOROY RETIREMENT COMMUNITY, TRADING POST
| PALM LAKE RESORTS                                                                                      ROAD, COOROY                    | 11