NCC Version:
NCC 2022 Volume 3
Area of NCC Requirements:
The report addresses compliance with storm water drainage requirements under the NCC, specifically provisions related to:
- Roof Drainage Systems (Vic E3P1) – Ensuring storm water is effectively drained.
- Overflow Systems (Vic E3P2) – Providing overflow devices for extreme rainfall.
- Water tightness (Vic E3P3) – Ensuring internal drainage components remain watertight.
- Design, Construction & Installation (Vic E3P4) – Requirements for storm water transfer, maintenance access, and mitigation of uncontrolled discharge.
Problem:
The storm water drainage system for the residential care facility faced challenges due to site constraints that prevented a conventional gravity-fed system. The required drainage to a raingarden and rainwater tank lacked a continuous downhill gradient, necessitating pipes to transport water upwards or horizontally. This deviation from standard gravity drainage risked water pooling, blockages, and non-compliance with NCC Deemed-to-Satisfy provisions, requiring an alternative solution.
Solution:
A Performance Solution was developed to meet NCC performance requirements using a charged storm water system that directs water to:
- A Raingarden
- A Rainwater Tank
Both solutions involve sealed, pressure-driven drainage systems designed to function under head pressure rather than gravity. The methodology includes compliance checks with AS3500.3 standards, ensuring sufficient static head, appropriate pipe sizing, watertight sealing, and maintenance access points.
Finalised Report:
Following a detailed engineering assessment, the report concluded that the Performance Solution meets the relevant NCC 2022 Volume 3 performance requirements. The system was demonstrated to function effectively despite the site constraints, ensuring compliance with NCC and AS3500.3 standards.