Stormwater Drainage

General guidelines and conditions for on-site drainage.

1. All building related plans submitted to the City of Melville, must include a site plan indicating the following Drainage details:
1.1 Existing ground levels or contours.
1.2 Proposed levels of paved or concrete areas.
1.3 Details of proposed roof and pavement drainage disposal systems.
1.4 Size (depth & diameter) and locations of all soak-wells.
Factors such as soil conditions, water table depth and capacity for storm events need to be taken into account by the appointed professional engineer.

2. Conditions applicable for all general residential developments:
2.1 All stormwater shall be retained and discharged on site.
2.2 All soak-wells installed in paved or concrete areas shall be provided with trafficable lids and made accessible for maintenance purposes.
2.3 Soak-wells to be no closer than 1.0m to a footing or boundary.
2.4 All soak-wells used shall be from an accredited supplier.
2.5 All soak-wells installed within flexible pavement areas (bitumen or brick paving) shall be provided with an appropriate base to prevent any subsidence of the well liners.
2.6 It is the owner’s responsibility to regularly clean and maintain on-site drainage systems to ensure its on-going functionality.
2.7 Residential sites located below road level shall have drainage systems designed to cater for a 1:100 ARI 24hr storm event.
2.8 Residential sites located above road level shall have drainage systems designed to cater for a 1:20 ARI 1hr storm event.

3. The following Design Conditions shall apply for Industrial and Mixed Use developments:
3.1 All drainage systems designed for the proposed developments shall be certified by a Registered Professional Engineer.
3.2 The design of the systems, shall conform to the requirements of the Building Code of Australia (BCA) and the Australian Standard (AS 3500).
3.3 It shall be the Engineers responsibility to demonstrate that a 1:100 ARI 24hr storm event is fully contained within the property boundary.

For further information, please contact the City of Melville Senior Design Engineer on 9364 0681.