Hydraulic fire safety system design
FRNSW require a statement of available pressure and flow (or equivalent information) to be obtained from the water network utility operator and provided with any referral or application for advisory, assessment or consultancy services on any development proposal which involves the design or alteration of a hydraulic fire safety system. The issue date of the statement of available pressure and flow (or equivalent) must fall within the twelve (12) months prior to the date of referral or lodgement.
Note: A hydraulic fire safety system is defined in schedule 2 of the Environmental Planning and Assessment (Development Certification and Fire Safety) Regulation 2021, and under section 22 (1)(b) the statement should accompany the application for a construction certificate.
The minimum design residual pressure of any reticulated water supply serving a hydraulic fire safety system is to be determined in accordance with AS 2419.1:2021, including whether the network utility operator’s hydraulic modelling used for the statement is calibrated or uncalibrated, and whether field test support is recommended as per Appendix L of AS 2419.1:2021.
If the development is to include a performance-based design, the statement of available pressure and flow should be sought prior to seeking consultation on the performance-based design brief (PBDB), so that consideration can be given to the hydraulic design requirements and proposed performance solution.
Note: When the available pressure and flow is not commensurate to the hydraulic design requirements, onsite water storage and fire pumps may be required and their location needing to be considered within the design. The PBDB should indicate if a large-bore suction connection will be required.
Any hydraulic fire safety system design must ensure accessibility of fire hydrants, including to any street fire hydrants or large-bore suction connections that are part of the fire hydrant system. The location of any required hardstand area serving a large-bore suction connection, required when there is insufficient flow in the mains supply, must also be considered within the design.
Note: A public road may not be suitable to serve as the required hardstand. Refer to FRNSW guideline Access for fire brigade vehicles and firefighters for further information.
Where the statement of available pressure and flow shows a sub-performing water main, consideration should be given to approaching the water network utility operator on the feasibility of upgrading the water main, particularly if other nearby developments are likely and the cost of any mains upgrade can be shared to be more cost effective and practical than providing onsite water storage and/or fire pumps.
Updated: 5th December 2024