Alternative water sources

 

• rainwater– collected from roof areas and stored in a rainwater tank;

• stormwater– collected from trafficable surfaces and stored in a stormwater tank;

• greywater– diversion and treatment systems can be used to collect and re-use wastewater from the bathroom and laundry;

• private dams (single dwellings only)– for toilet flushing, laundry, garden irrigation;

• reticulated alternative water supply (approved multi-dwelling developments only)– recycled wastewater supplied by a water authority or central authority via a reticulated system to individual lots for non-potable use;

• central on-site recycled water systems (multi-dwelling developments only)– for toilet flushing, laundry, garden irrigation; and

• hot water recirculation and diversion– collecting water from hot water fittings until the water reaches the desired temperature.

For each water use in the development, you must nominate a water source. The source may be mains-supplied potable water or one of the recognised alternative water sources.

Alternative water sources are optional, but in most cases a dwelling will need to nominate an alternative water source in order to achieve the required water target.

Note: There are limits to alternative water use for some alternative water sources.

BASIX does not recognise the following water supplies as alternative water sources. Please refer to the relevant help notes for further information:

• Groundwater.

• River or 'Raw' Water

• Onsite Sewage Management Systems

Hotwater diversion

Hot water diversion systems divert hot water draw-off (cold water in the hot water pipe) until the hot water at the fixture reaches the set temperature. The diversion is triggered by the operation of the hot water tap, and the water is stored in a hot water diversion tank. This water is available as an alternative water source for toilet flushing.

If a hot water diversion system is selected the saved diverted water will be automatically nominated as the alternative water source for toilet flushing in BASIX.

To maximise the water saving benefits, the system must be permanently connected to not less than all shower fittings, kitchen sinks, and all basins located within the dwelling. This will require discussion with your plumber/hydraulic designer, to ensure they understand the plumbing requirements for these systems, and factor this in during design/installation stages of the development.

Further information and installation advice is available from the respective manufacturers of these systems.

Note: a hot water diversion system is not an instantaneous hot water system. For further information on hot water systems, refer to the help notes within the 'Energy' section.

Greywater

Greywater means wastewater that does not contain human excreta. Greywater includes wastewater from the laundry, bath, shower and bathroom basin, but not toilet. Kitchen basin wastewater may only be included if it is treated, because it may be heavily polluted with food particles, oils and fats.

BASIX recognises the following types of greywater system:

  • Greywater diversion - water re-used for subsurface garden irrigation
  • Greywater treatment - treated water re-used for garden irrigation, clothes washing and toilet flushing depending on the level of treatment

All forms of greywater are capable of transmitting disease, and can have a negative impact on your garden if not installed and managed correctly.

Additional guidance on greywater reuse in single dwellings is available from the NSW Office of Water and the NSW Health Department.

Greywater diversion systems

A greywater diversion system is a system that diverts household greywater for re-use. It does not treat or store the water.

You will need to nominate the sources of water that will be collected for diversion. Diverted greywater can only be used for sub-surface garden irrigation.

Greywater diversion systems should not be used in areas identified as having major limitations to on-site disposal. Such areas include locations with shallow water tables, highly porous soils (such as sand beds) or with visible signs of surface dampness (such as seeps, soaks or springs). Some other limitations that must be assessed before adopting greywater diversion include soil characteristics, salinity and other contaminant loads of wastewater, scheduling application and maintaining sewer connections to provide an alternative disposal option in the case of on site system failure.

The installation of a greywater diversion system does not require approval by your local council if it is installed in accordance with the Plumbing and Drainage Code of Practice. The Plumbing and Drainage Code of Practice can be found on the NSW Office of Water website.

Greywater treatment systems

A greywater treatment system is a system that collects, treats and stores household greywater for re-use.

You will need to nominate the sources of water that will be collected for treatment. "All other household" refers to water collected from the kitchen sink. Treated greywater can be used for irrigation, toilet flushing and laundry (clothes washing).

Greywater treatment systems should not be used in areas identified as having major limitations to on-site disposal. Such areas include locations with shallow water tables, highly porous soils (such as sand beds) or with visible signs of surface dampness (such as seeps, soaks or springs). Some other limitations that must be assessed before adopting greywater treatment and reuse outdoors include soil characteristics, salinity and other contaminant loads of the greywater, scheduling application and maintaining sewer connections to provide an alternative disposal option in the case of system failure.

How do I get approval for my Greywater treatment system? 

You need to obtain approval from local council to operate a single household greywater treatment system. Your local council determines the final conditions of the approval to operate the greywater treatment system, including installation, maintenance and monitoring requirements.

Local councils can only approve a greywater treatment system that has been accredited by NSW Health. A current list of NSW accredited systems can be found on the department's website.

Sources not recognised by BASIX

The following water sources are not recognised by BASIX as alternative water sources:

  • Groundwater
  • River or "raw" water
  • On-site sewage management systems

Applicants are required to achieve their water savings target by nominating a recognised alternative water source or by improved water efficiency.

Note: Alternative Assessment is not available for groundwater or river water applications.

Groundwater

Groundwater is that part of the water system that exists beneath the earth's surface, including underground streams and aquifers. It is a significant source of water for agriculture and is also the main domestic water supply for many communities and properties.

Landholders may have a basic right to access groundwater beneath their property for domestic (household) and stock purposes, so BASIX does not award savings for connecting to it.

River or "raw" water

River water is a significant source of water for agriculture and is also the main domestic water supply for many communities and properties.

Applicants can still utilise river and raw water where available, subject to relevant approvals, however BASIX treats river water as a potential potable supply and does not award savings for connecting to this supply.

Onsite Sewage Management Systems

Sewage is wastewater that includes both greywater and blackwater. An "Onsite Sewage Management System" (OSMS) is a system that allows for the collection, treatment and disposal of a single households wastewater. They are also referred to as household wastewater treatment systems. Unlike greywater treatment systems, these systems do not treat water to a standard suitable for re-use and are therefore not recognized as an alternative water source.

Certain wastewater treatment systems require a nominated irrigation/landscape area for wastewater disposal purposes. BASIX does not require this nominated area be included in garden and lawn area calculations. To claim this concession, ensure that the area is clearly marked 'effluent disposal area' on the plans submitted to council.

All forms of wastewater are capable of transmitting disease and the installation of a wastewater treatment system requires approval by your local council. Contact your local council for further information.

Further information about household wastewater disposal and on-site sewage management systems is available from the Department of Local Government.

Rainwater harvesting systems

Rainwater means water discharged from non-trafficable roof areas within a development site. A rainwater tank is a tank designed for the capture and storage of rainwater collected from all site roof areas (including separate garages/sheds etc). Rainwater tanks include all purpose built rainwater storage devices that meet the relevant standards and criteria.

BASIX assesses rainwater based on:

  • Capacity of the rainwater tank you are installing in litres
  • Area of the roof catchment to be connected to the rainwater tank
  • Uses the water from rainwater tank will be allocated to
  • Diversion of overflow from your rainwater tank to another tank for collection and re-use

Uses of Rainwater

NSW Health supports the use of rainwater for: toilet flushing, washing clothes, hot water systems, garden watering, car washing, filling swimming pools, outdoor spas and ornamental ponds. See Alternative Water Use. Rainwater can be used for firefighting, however, the portion of a rainwater tank designated for firefighting is not counted as part of a BASIX rainwater tank.

NSW Health guidelines (http://www.health.nsw.gov.au/environment/water - NSW Health website) should be referred to when harvested water is being considered for all uses. NSW Health does not recommend the use of rainwater for drinking purposes where a reticulated potable water supply is available.

To maintain a good quality rainwater supply, a rainwater tank requires good design and installation, and a regular ongoing maintenance regime.

You should contact your local council and/or a professional rainwater tank retailer for further information regarding the design and installation of rainwater tanks in your area.

Individual rainwater tanks in multi unit dwellings may be used to supply water to common areas, to single dwellings, or to more than one dwelling. Multi unit developments may also select the option of a central water tank to collect and supply water to common area or the individual dwellings.

 

Further information:

Alternative water sources

BASIX recognises the following alternative water sources:

  • Rainwater– collected from roof areas and stored in a rainwater tank
  • Stormwater– collected from trafficable surfaces and stored in a stormwater tank
  • Greywater– diversion and treatment systems can be used to collect and re-use wastewater from the bathroom and laundry
  • Private dams (single dwellings only)– for toilet flushing, laundry, garden irrigation
  • Reticulated recycled water– recycled wastewater supplied by a water authority or central authority via a reticulated system to individual lots for non-potable use
  • Central on-site recycled water systems (multi-dwelling developments only)– for toilet flushing, laundry, garden irrigation; and
  • Hot water recirculation and diversion– collecting water from hot water fittings until the water reaches the desired temperature

For each water use in the development, you must nominate a water source. The source may be mains-supplied potable water or one of the recognised alternative water sources.

Alternative water sources are optional, but in most cases a dwelling will need to nominate an alternative water source in order to achieve the required water target.

Note: There are limits to alternative water use for some alternative water sources.

Alternative water sources not recognised by BASIX

BASIX does not recognise groundwater, river water or onsite sewage management systems as alternative water sources. Please refer to sources not recognised by BASIX for further information.

 

Alternative water use

Based on guidance from relevant authorities, alternative water can be used for the following household uses in BASIX:

 

garden
and lawn

all toilets

laundry

all hot water

pool and
spa top-up

all house
hold uses

cooling towers

Individual
rainwater 

yes yes yes yes yes yes*** NA

Common
rainwater 

yes yes yes no no no yes

Stormwater
treated 

yes * yes * yes * no  no no yes *

Stormwater
untreated 

 yes  no  no  no  no  no  no

Greywater
treated 

 yes *  yes *  yes *  no  no  no  yes

Greywater
untreated 

 yes  no  no  no  no  no  no

Reticulated
alternative water 

 yes **  yes **  yes **  no  no  no  no

Private dam

 yes  yes  yes  no  no  no  NA

water 

 yes **  yes **  yes **  no  no  no  yes **

*Check with local council and system manufacturer/designer for accredited uses
**Check with scheme operator for permitted uses
*** NSW Health does not recommend the use of rainwater for drinking purposes where a reticulated potable water supply is available

Reticulated recycled water

Reticulated recycled water is recycled water supplied by a water authority or central authority for non-potable use.

Note: reticulated recycled water may only be selected if your site is within the area serviced by a recognised recycled water scheme. Please contact your water provider to ensure that reticulated recycled water will be available for your development.

BASIX assesses reticulated recycled water based on:

  • Name of the reticulated alternative water scheme you will be connecting to
  • Uses the water from the alternative recycled water scheme will be allocated to– this is determined by the schemes operators

In most cases recycled water involves the treatment and re-use of sewage effluent, but recycled water can include any type of wastewater that has been captured and treated for reuse, such as; greywater or stormwater. The majority of recycled water schemes allow garden and toilet end use only, however some also allow connection for laundry (cold water washing machine) use.

If you believe your development is located in an area serviced by a reticulated alternative water supply and BASIX does not recognise this you need to contact the scheme provider for further information. Schemes can only be recognised in BASIX as a result of an application from the scheme operator and based on the scheme meeting certain approvals and criteria.

Multi-unit developments have the option of developing and operating a private recycled water scheme to capture, treat and distribute recycled water for their site. This is not a 'reticulated alternative water scheme' for the purposes of BASIX and is instead dealt with as a central on-site recycled/alternative water supply.

Further information:

For more information about reticulated alternative water schemes and the use of recycled water from these schemes contact your local council or local water utility.

Stormwater

Stormwater means water collected from trafficable surfaces, including paved or ground surfaces. A stormwater tank is designed to capture and store stormwater.

BASIX assesses stormwater based on:

  • Size of the stormwater tank you are installing in litres, being the volume available for water storage in addition to (i.e. excluding) any requirement for stormwater detention or retention for your site.
  • Area of the catchment (i.e. water collection area) to be connected to the stormwater tank. This is entered by catchment type.
  • Uses the water from stormwater tank will be allocated to, depending on whether it is treated or untreated.

Roof areas can also be diverted for collection in a stormwater tank (rather than a separate rainwater tank) however untreated stormwater can only be used for garden irrigations (and should not be used on edible plants).

Treated stormwater can be re-used for garden irrigation, toilet flushing, and laundry (cold water washing machine) use, provided it meets the requirements set by NSW health.

As a guide, the use of treated and untreated stormwater for garden irrigation is subject to the same constraints and environmental protection measures as apply to greywater re-use.

The volume of the stormwater tank specified as part of BASIX water commitments must be in addition to any minimum tank requirements specified by the local council for detention and/or retention.

Multi unit developments may also select the option of a central water tank to collect and supply water to common area uses or the individual dwellings.

Further information:

You should contact your local council and/or a professional hydraulic engineer for further information regarding the design and installation of stormwater tanks in your area.

Stormwater Industry Association promotes innovative and sustainable practice technologies, standards and policies that minimise adverse environmental, social and economic impacts.

Subcategories