Aligning domestic garden bore sprinkler roster with the scheme water roster

Overview

Across Perth and Mandurah, domestic garden bores collectively abstract around 90 GL (gigalitres, or billion litres) which is equivalent to 90 Optus Stadiums full of water per year, or 22 per cent of all water abstracted from our groundwater systems.

Currently, domestic garden bores are able to be used for garden watering three days a week in spring, summer and autumn. As a necessary measure to protect our groundwater resources, there is a proposal to reduce the domestic garden bore roster to align with the two-day-a-week scheme water roster in the Perth and Mandurah areas.

Changes to sprinkler rosters would not be introduced until 1 September 2022, giving garden bore owners the opportunity to adapt their gardening practices.

Domestic garden bores are not licensed and there is no limit to the volume of water able to be taken. Various studies on residential water use over the past two decades have found that on average, domestic garden bores use significantly more water on their gardens than scheme water users - about three to four times more.

By reducing the garden bore sprinkler roster to two days per week, up to 30 GL of groundwater can be saved every year. These savings would mean more groundwater is retained in the system and see a rise or stabilisation of the water tables particularly in urban areas.

Improved water tables would have significant benefits to urban street trees which contribute to the liveability of our suburbs and reduce urban heat island effect. Street trees are heavily reliant on the watertable being maintained at levels accessible to root systems to prevent tree deaths.

Urban wetlands would also benefit through stabilisation of the water tables with environmental benefits expected in wetlands such as Perry Lakes, Herdsman Lake (Ngurgenboro), Lake Gwelup, Carine Swamp, Star Swamp, North Lake, Bibra Lake and Lake Forrestdale.

The winter sprinkler switch off will remain in place from 1 June to 31 August each year, and the ban on daytime watering between 9am and 6pm will remain unchanged.

The McGowan Government currently assists householders to help them make their gardens more water efficient through a range of programs, including rebates on smart irrigation technology and free spring sprinkler system check-ups.

For more information on the range of measures Government has in place to assist householders and businesses to be more waterwise, please visit the Water Corporation’s website.

For more information on garden bores, the importance of groundwater and how to be waterwise with your garden and bore, visit the Be Groundwater Wise website.

Rebalancing Perth and Mandurah’s Groundwater Systems questions and answers

Consultation

Between 19 November 2021 and 28 February 2022 the State Government also sought feedback on a proposal to align the domestic garden bore sprinkler roster with the two-day-per-week scheme water roster.

The consultation period has now closed. The department would like to thank all those who made submissions and has prepared a consultation summary report that summarises the submissions received and the department’s response. The summary report is available for download.