ADAMS+SPARKES Response to Information Request (Gympie Tce) 160401

17-0022/T0070




Figure 1 – Catchment Plan and Peak Flow Rates

2.2.               DOWNSTREAM BOUNDARY CONDITION

Two scenarios have been assessed, as described below:

      1.     Free flowing outlet,
      2.     Free flowing outlet with 50% blockage of inlet pits, and
      3.     Highest Astronomical Tide (HAT) – following the procedure for calculating high water levels detailed in
             Queensland Tide Tables Standard Port Tide Times (DTMR, 2017), the HAT for Munna Point has been
             determined and applied to the assessment. A constant water level of 1.59 m AHD was applied to the
             downstream boundary for this scenario.

2.3.               STORAGE AREA

Based on the contours available, a storage volume for ponding was defined in the form of a depth-area
relationship. This volume was defined between 1.25 m AHD and 1.75 m AHD, as summarised in Table 1.

Table 1 – Storage Relationship for Ponding Area

                    Level (m AHD)                      Depth (m)                            Area (m²)

                             1.25                          0                                  1,080

                              1.5                         0.25                                1,803

                             1.75                         0.5                                 4,421


Environment. Engineering. Education                                                                            Page 2