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

17-0022/T0070




Figure 3 – Proposed Drainage Infrastructure included in XPSWMM

2.5.               MODEL RESULTS

The peak water level at the inlet pits in the Sea Scouts site has been assessed for each of the scenarios modelled.
Based on these results, the peak water level during the 100 year ARI scenario is:

      1.     Scenario 1 (free outlet) – peak water level = 1.43 m AHD
      2.     Scenario 2 (free outlet with 50% blockage of inlet pits) – peak water level = 1.47 m AHD
      3.     Scenario 3 (HAT) – peak water level = 1.69 m AHD


3               SUMMARY
The peak water level in the Sea Scout site has been assessed in the post-development scenario. Hydraulic
modelling indicates the peak water level will range between 1.43 m AHD and 1.69 m AHD during a 100 year ARI
event. During major flood events, the whole Sea Scout site will be inundated and the impact of the proposed
development will not have any adverse impact on the Sea Scouts property during such an event.

The proposed RCBC in the south-western corner of the development provides relief drainage for the Sea Scout
site. During the HAT scenario, runoff is conveyed from the Sea Scouts at a flow rate of 130L/s towards Gympie
Terrace.




Environment. Engineering. Education                                                                           Page 4