Find out about the survey requirements that are involved if you are building in close proximity to our sewer lines.
Our sewer lines need to be clear of building developments to ensure:
- access for maintenance and replacement
- the building load does not cause damage to the pipe.
You will need to meet the following requirements before we approve your building plans.
Any building proposal within 1m of a sewer line requires surveyed measurements showing the line in relation to the property boundary and the proposed building.
A surveyed measurement will also be required where the building proposal is within 3m of a sewer line where:
no offset measurement provided
the main is greater than 300mm diameter
the main passes through the land at an angle
the main is a pressure main.
Buildings are generally permitted to within 0.6m of pipe work if piling or other protection is provided, but great care needs to be taken when working this close.
The accuracy of the location of water, sewer and drainage mains is generally within 0.5m of either side of the alignment detailed on our plans or diagrams. In older areas it is important that issues affecting the design of the development are identified early in the planning stage of the project.
What needs to be surveyed?
- The centre-line of the sewer – adopt the centre of the access chamber or excavate.
- Access chambers.
If the final location and shape of the proposed building isn’t clear at the time of the feature survey, the surveyor should include the following notation to ensure the designer is aware of these requirements:
- "If the proposed building is less than 3m off the sewer main, Water Corporation may require a surveyed location of the sewer main prior to approval of the building application".
Feature survey levels must be provided in Australian Height Datum (AHD) as it assists in ensuring the building can be adequately served by the sewer and makes the design of piling easier.