Property drainage design and onsite detention assessment

* Indicates required field

This application is to obtain Council’s approval of the detailed drainage design as per Council’s guidelines (759.9 KB).

Planning permits issued under the Planning and Environment Act 1987 may require an on-site detention system (OSD) to be installed on the subject site to the satisfaction of Brimbank City Council (Council).  OSD provides temporary storage of stormwater run-off to ensure that the receiving drainage system is not overloaded. Council recommends that the developer engages a private engineer or designer that is experienced in the design of OSD to liaise with Council’s engineers.

If you are required to apply, it will be noted as a condition on the Planning Permit, e.g. “An on-site stormwater drainage retention/detention system must be installed on the subject land to the satisfaction of the Responsible Authority". Generally plans are submitted for approval for residential developments with three or more units.

If you require parameters applicable for the design of the property drainage/onsite detention (OSD) as per the requirement of the Planning Permit conditions, please first contact Engineering Services via before completing this application.

Application fees

  • $328.40 for property area up to 1000m2
  • + $58.50 per 1000m2 for property area greater than 1000m2

To apply you will need

  • Planning permit number

- Stormwater design computations (OSD4W or any appropriate calculation method) including:

  • Storage requirement
  • Orifice size calculation
  • Available storage
  • Pump calculation as per AS/NZS3500, if applicable

- Design plans

  • Layout plan with levels (pipe inverts, top of pits & pavements etc.), dimensions and relevant notes
  • Details of control pits, storage pits, pump well, storage tanks, backfill requirement etc.

- Copy of the legal point of discharge (LPD) advice and planning permit

- A credit card to make a payment

This form will take about 5 minutes to complete.

Site address *
Last updated: 2 March 2023 - 2:31pm