Approved plan - Site Based Stormwater Management Plan - Job Ref SC-8407 - Revision B - 24 March 2020

SC-8407 – 45 Maple Street, Cooroy                                                              9


4.3.5    Outlet Condition
The subject site is not impacted by regional flooding or tidal backwater.


4.3.6    On-Site Detention
It is calculated from the development site plan that the proposed development will increase impervious
areas on the site. The proposed increase in impervious areas has the potential to increase peak flow rates
to the existing drainage system. To mitigate potential increases in flow rates it is planned to detain
stormwater flows on-site and discharge at a mitigated rate to the existing stormwater infrastructure system.


Mitigation of flow is provided by the following volumes:
        Catchment A – Minimum 60kL of on-site detention volume.

A concept drainage layout plan has been included as Appendix A of this report.