This Part applies to a rainwater service supplied by stored rainwater collected from a roof, where a separate cold water service is provided for drinking and personal hygiene from a Network Utility Operator's supply.
This Part does not apply to rainwater used only for irrigation purposes.
Where water provided by a Network Utility Operator is not available or not utilised as the primary water source for drinking and personal hygiene, roof collected rainwater is considered to be a cold water service supplied by an alternative source.
A rainwater service must be designed and installed so as to operate in a way that avoids the likelihood of inadvertent contamination of any drinking water service and minimises any adverse impact on building occupants, the Network Utility Operator’s infrastructure, property and the environment.
a static pressure within a building of not more than 500 kPa; or
have water pressures suitable for the correct functioning of the fixture or appliance where water pressures outside of (a)(i) and (a)(ii) are required.
A rainwater service must ensure pipework water velocity does not exceed 3 m/s for more than 1% of the time that the water is required during the normal peak flow.
Explanatory information
During the hour of heaviest usage in reticulated rainwater service pipework, a velocity of 3 m/s must not be exceeded for 99% of the time that any downstream fixture is in use.
A rainwater service must comply with Section 15 of AS/NZS 3500.1. Additionally, after Clause 15.3.3(c) insert (d)—
(d) For Class 1 buildings and extensions or additions to Class 1 buildings the following applies.
Where a water service from a rainwater tank interconnect with a water service from a water main supply, the supply to a fixture, appliance or water outlet shall be maintained by a device/mechanism that facilitates a seamless automatic switching from one water service supply to another and vice versa without the need for manual intervention.
NCC Title
General requirements
NCC State
SA
NCC Variation Type
Replacement
NCC SPTC Current
General requirements
NCC ID
_2e8b0f77-9f25-4a76-bc41-d1780fb8d720
NCC Blurbs
A rainwater service must comply with Section 15 of AS/NZS 3500.1.
Notes
The Victorian NCC 2019 rainwater tank variation (VIC V2.6.1 and V3.12.0 respectively) remains in effect until 30 September 2023 after which the following takes effect:
A rainwater tank must be installed in a Class 1 building in accordance with the regulations made under the Building Act 1993 (Victoria).
(1) Cisterns or flushing devices for water closet pans must—
be a minimum of 3 Star WELS rating, discharging not more than 6 litres or 4.5 litres for a full flush; and
have a dual flushing mechanism.
(2) Cisterns or flushing devices for urinals must—
be a minimum of 2 Stars WELS rating, discharging not more than 2.5 litres; and
serve a single stall or 600 mm length of continuous urinal wall; and
not be automatic or set-cycle.
Applications
The flush volumes of B6D4 may be within a tolerance of—
±0.5 litres for the full flush of a 6/3 litre cistern; or
+0.5 litres for the reduced flush of a 6/3 litre cistern; or
±0.2 litres for a 4.5/3 litre cistern.
Exemptions
The requirements of B6D4 do not apply to a vacuum drainage system.
The requirements of B6D4(2)(c) do not apply to a programmed solenoid operated flushing system if programmed to shut down during extended periods of non-occupancy of a building.
Explanatory information
Prior to installing a programmed solenoid operated flushing system, further advice should be sought from the authority having jurisdiction.
Where sensor control is used for urinal flushing, sensors should be located to avoid unnecessary ‘nuisance’ flushing triggered by pedestrian traffic.
AS/NZS 6400 Water Efficient Products - Rating and Labelling, provides the basis for the rating and labelling of a range of products under the mandatory Water Efficiency Labelling and Standards (WELS) scheme.
B6D4 Water efficiency outlines the minimum level of water efficiency for certain plumbingproducts and fixtures, however the adoption of greater efficiency products and technologies should be considered.