LATEST - RECEIVED 23.10.26 - Attachment 1A - Other Change Decision Notice · 132005.638.06

                                        Page 58 of 72
Document Set ID: 24377726
Version: 13, Version Date: 23/12/2025


[OCR of page images]
Client: Noosa Shire Council

 

4.0 STORMWATER QUANTITY

Stormwater quantity management for the site ensures a “no-actionable nuisance” design for the proposed
development. Development of the site will result in an increase in impervious area and a corresponding
increase in peak stormwater runoff. However, as the proposed development area (2.24 ha) is much smaller
than the overall catchment (287 ha) the minor increase in the fraction impervious has a negligible effect on
the overall catchment peak discharges. As the proposed development has a fraction impervious higher than
the overall catchment and is located closer to the downstream boundary (outlet) the peak discharge will
arrive at the outlet much sooner than the overall catchment. Therefore, the increase in the peak discharge
for the overall catchment will be negligible. Further, stormwater detention is not required for the proposed
development.

Refer to Figure 4-1 for the overall stormwater catchment. Refer to the Flood Impact Assessment (Report No.
M25-0045Rpt Issue A) prepared by Covey Engineers for further details.

 

 

 

 

 

 

 

 

 

 

Figure 4-1 Overall Stormwater Catchment (extract from report no. M25-0045Rpt)

 

Project No: 244035
M25-0042 Rpt Issue A

 

Document Set ID: 24377726 Page 58 of 72

Version: 13, Version Date: 23/12/2025