About public local network separation investigations and design

The public network will be designed to go in road carriageways wherever possible for ease of future maintenance and it is designated for this purpose. Due to factors such as topography, some pipes will also need to go through private property.

To design the new public network, several key factors are taken into consideration for the placement of these pipes:
  • Ease of access for maintenance in the case of blockages, breaks or replacement.
  • To allow the network to operate by gravity, the pipes need to flow downhill to allow them to operate without having to pump uphill and ensure ongoing service are economical and sustainable.
  • The proposed horizontal and vertical alignment of the new drainage generally follows the existing combined pipes, to enable connection of private property using existing pathways.
  • Where the pipe needs to go through private property, we follow boundaries as close as possible to minimise limitations on property owner’s future development or other activities
  • The proposed public wastewater and stormwater system has been designed deeper than the existing combined pipe, aiding private drainage to travel downhill to the local pipes (this reduces wastewater being stagnant in pipes and keeps them flowing), however, the pipelines still will be put in as shallow as possible to reduce risk to our maintenance staff when doing routine inspections.
We will talk to property owners where public pipelines are required on their property to help them understand the design reasoning and position of the pipelines have been chosen. We now have a preliminary design completed of the new public network. See the new design of the public network here.

About private drainage separation investigations and design

Each private property is different. Properties in the area have a variety of separation required and some have already been separated.

We will work with you to understand the level of separation required on your property which will fall into one of these categories:
  1. Your property was built with combined drainage and has had no separation work. This would most likely require separation from the public network to the house on the property.
  2. Your property was built with separated drainage but only to a point inside your property’s boundary. This may require separation work only up to this unseparated point.
  3. Your property is separated and requires no further separation work.
Once we understand your unique situation, we will provide you with the most practical design of any new drainage required. We look at a number of factors for your new drainage including, direct route from dwelling to connect to the corresponding local pipelines, downhill flow, topography, alignment with current pipelines already existing and along areas of the property boundary and where possible we can work with you to avoid any areas for planned future development.

Read: Who is responsible for pipes, see 'wastewater'.