WSA 02 Gravity Sewerage Code
What the code covers, and how it relates to authority supplements.
WSA 02 is the Gravity Sewerage Code of Australia, published by the Water Services Association of Australia (WSAA) as part of the WSAA Codes. It provides a nationally consistent basis for planning, designing and constructing gravity sewer systems, covering flow estimation, pipe sizing, grades, cover, maintenance holes, materials, construction and asset records.
Most Australian water authorities adopt the code together with a local supplement that amends or adds to it. The code is copyright material, so this library summarises the subjects it governs and points you to the governing edition rather than reproducing its criteria.
Key design considerations
- Confirm the governing edition, including amendments and the authority supplement, at the start of the project.
- The supplement normally prevails for that authority's area where it conflicts with the base code.
- The code addresses the whole asset life cycle, not only hydraulics: design, construction, testing, acceptance and handover records.
- Design criteria such as minimum grade, cover and maintenance hole spacing are set by the code and supplement together, not by general practice.
- Most authorities require a design report and drawings in a defined format, and issue approval before construction.
Design checks
- Adopted edition and supplement recorded in the design basis.
- Each design criterion traced to a specific code or authority document.
- Submission and approval requirements identified before documentation.
Standards and authority references
- WSA 02 Gravity Sewerage Code of Australia (current edition), Water Services Association of Australia
- The water authority's supplement and standard drawings
Confirm the current edition, amendment and any local supplement before applying any of the above.
Limitations and assumptions
- Specific criteria are not reproduced here; work from the current edition and the authority's documents.
- Requirements vary between authorities and change between editions.
This reference is general engineering information. Confirm requirements against WSA 02, the current Australian Standards and the local water authority's supplement before use in design, and obtain project-specific advice for the conditions at hand.