WQ 4.1 Drought-Tolerant Landscapes
Where potable water is used for irrigation, provide drought-tolerant plants for at least 50 per cent of the landscaped site area (including at-grade landscapes, vegetated roofs and walls).1,2
WQ 4.2 Water Efficient Fixtures
Install water fixtures that achieve at least a 40 per cent reduction in potable water consumption for the building (not including irrigation) over the baseline water fixtures.3
WQ 4.3 Efficient Irrigation
Where soft landscaping exists on the site, reduce potable water use for irrigation by 60 per cent.4,5
Specifications and Resources
- Drought-tolerant landscapes and species are provided in accordance with the following City of Toronto guideline document, Drought Tolerant Landscaping: A Resource for Development. This requirement does not apply when non-potable water is used for irrigation.
- In choosing tree species, preference should always be given to those native to the area. Where it can be clearly demonstrated that the planting of native tree species would not be appropriate due to site constraints often encountered in urban settings, Urban Forestry may accept non-native, non-invasive species better suited to the particular site.
- Refer to LEED® V4 BD+C: WE Credit Indoor Water Use Reduction, for further details on how to achieve this requirement. Calculations will be based on estimated occupant usage and baseline fixtures including toilets, urinals, faucets, shower heads. Baseline fixtures include the following: toilets (6.0L), urinals (3.8L) residential faucets (8.3 LPM at 414 kPa), commercial lavatory (restroom) faucets (1.9 LPM at 414 kPa), shower heads (9.5LPM at 550 kPa).
- Refer to LEED® V4 BD+C: WE Credit: Outdoor Water Use Reduction Option 2 for further details on how to achieve this requirement. Reductions in potable water must be calculated from a midsummer baseline case. Methods to reduce potable water use for irrigation include high-efficiency irrigation and use of captured rainwater and use of greywater.
- Non-potable water sources include greywater or rainwater. Greywater may be used for subsurface irrigation if treated as per the requirements of the Ontario Building Code and CAN/CSA-B12.