Typical Engineering Details
The standard details a sewer design package normally needs.
Most authorities publish a standard drawing set. Using those details shortens approval and keeps construction consistent with the asset register; project-specific details should be the exception and should be justified.
The details that normally appear on a gravity sewer drawing set are listed below. Confirm the current revision with the authority before they are issued for construction.
Reference table
| Detail | Purpose |
|---|---|
| Maintenance hole, shallow and deep | Structure geometry, cover, access, benching |
| Drop connection | Internal or external drop at high inlet falls |
| Property connection junction | Connection geometry and sealing at the property boundary |
| Trench and bedding section | Bedding class, embedment, backfill zones, marker tape |
| Cover slab and surround | Shallow cover protection under trafficked surfaces |
| Service crossing encasement | Reduced separation at a crossing |
| Termination and end of line | Access and venting at the head of the system |
| Concrete encasement | Protection where cover or separation is inadequate |
Key design considerations
- Confirm the authority's current standard drawing numbers and revision.
- Do not modify a standard detail without documented justification and approval.
- Ensure the details match the specification and the quantities, since discrepancies cause claims.
- Show transitions between detail types clearly on the long section.
- Include survey and setting-out references so the detail can be constructed.
Design checks
- Every detail referenced on the drawings exists in the current authority set.
- Details consistent with the design levels, diameters and load class.
- Quantities measured from the same details that are drawn.
Standards and authority references
- Authority standard drawing set
- Authority specification
- WSA 02 (current edition)
Confirm the current edition, amendment and any local supplement before applying any of the above.
Limitations and assumptions
- Detail geometry is not reproduced here.
- Standard details remain valid only within the conditions they were prepared for.
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.