BASIX assesses private dams based on:
- Catchment area - the areas diverted to the dam. Can include roof areas, pervious and impervious ground surfaces
- Surface area and volume of the dam - in square metres and kilolitres
Private dams can be used to harvest water for toilet flushing, laundry, garden irrigation in single dwelling developments only, subject to relevant approvals and licences.
The dam nominated as an alternative water source for BASIX must be exclusively for household use. Water stored for agriculture, stock watering, firefighting or stormwater detention purposes cannot be included in this calculation.
For more information on private dams and the approvals and licence requirements for their construction, refer to advice provided by the NSW Office of Water.
The catchment area of the dam includes any diverted roof area, impervious areas, and the remaining pervious areas:
- Impervious areas are surfaces that do not allow natural infiltration of rainfall to the underlying soil and include concrete, tiled and timber surfaces.
- Pervious areas are surfaces that allow natural infiltration of rainfall to the underlying soil and include gardens, lawns, pasture and native vegetation stands.
Surface area and volume
- Measure the surface area and volume of the dam when full. The area must be entered in square meters (m²).
- The volume must be entered in kilolitres (note: 1 kilolitre = 1000 litres = 1m³).
- Do not include water stored for agriculture, stock watering, firefighting or stormwater detention purposes in this calculation.