124-002 Technical Memorandum Revision B

Figure 2 – Proposed stormwater tank location
Source: BRW Hydraulics




                     PROPOSED HYDRAULIC DESIGN

                               CHARGED DRAINAGE LINES

The maximum potential head on the charged line is 2.600m and measured between the Ground floor roof
and the discharge point at the kerb. With the charged roof water line running full the head loss and flow
rates in the pipe discharging to the kerb are as follows:


    •    23m of 150mm PVC, equivalent length including fittings = 40.5m. Flow rate = 19.3L/s. Therefore the
         Headloss in 150mm PVC pipe (6.5m/1000m) = 0.263m


    •    6.5m of 150mm PVC, equivalent length including fittings = 20.0m. Flow rate = 14.4L/s. Therefore the
         Headloss in 150mm PVC pipe (4.0m/1000m) = 0.08m


    •    26m of 100mm PVC, equivalent length including fittings = 30.5m. Flow rate = 6.2L/s. Therefore the
         Headloss in 100mm PVC pipe (4.3m/1000m) = 0.134m

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