RFI - Attachment 4 - Engineering Response Package · MCU22/0171

DME Projects Pty Ltd
P.O. Box 7481
Sippy Downs, QLD, 4556
Tel 0438 157 612
ABN 79 224 274 637

                                         Response to Information Request – 128 Gympie Tce Noosaville
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structure (flood gate strip drain) and the submerged outlet in Gympie Terrace - during an event
where all drains are at capacity and overland flows are active between Gympie Terrace and Mill St.
The below images identify the flow paths and critical levels at location just before surface flows are
considered to be free draining to the river. Images show that generally there are no obstructions to
flow once water levels overtop the back of kerb and verges and can flow to the river. The water
surface level in Gympie Tce at which the internal system will cease to be 100% effective for site
catchments is RL 1.75m. This outcome does not rely on capacity of the underground network. An
increase in average rainfall will not impact on the performance of the overland flow paths identified.
If water level in Gympie Terrace exceeds RL1.75 it is likely to be a result of riverine flooding. Under
these conditions the strip drain/flood gate channel can not free drain to the street and the flood
gate will start to activate (from internal catchment runoff only). Non-return devices in the outlet
pipes will ensure that flood gate strip drain is isolated from the rest of the system and that external
flood waters do not flow back into the site.




                                                                             Noosa Infrastructure Mapping




                                                                                        Eastern Flow Path