NEW Yarragadee bores and an integrated water scheme for Donnybrook, Capel and Peppermint Grove Beach are some of the suggestions for securing water supply in local areas in a report on the long term outlook for water supplies in the South West.
The report was developed with significant input from councils, industry, government agencies and communities throughout the South-West over the past 18 months.
“The Water Corporation predicts that over the next 50 years, the demand for water from its customers in the South West will more than double from 12 billion litres per year, to nearly 30 billion litres per year,” Water Minister Mia Davies said.
“Rainfall over the past four decades in the South West has also reduced, and in some parts quite significantly, meaning good planning is vital to secure water supplies for the future.
“The Water Corporation’s Water Forever South West document outlines plans to develop new water sources, reduce water use and increase water recycling to achieve water security in the face of a drying climate.”
The department has partnered with the three South-West water service providers (Water Corporation, Aqwest and Busselton Water) to plan for the scheme water needs of their customers that align with the State’s growth projections and efficiency targets.
Water Forever: South West Final Report focuses on the need for reducing water use in its proposals for securing water supply.
In the Boyanup area, the Water Corporation is currently licensed to take up to 325 million litres per year from two Yarragadee bores to provide drinking water for about 840 people.
The report suggests securing water supply in this area through expanding the groundwater scheme by constructing an additional Yarragadee bore and five kilometres of pipeline, and upgrading the existing water treatment plant.
This would provide a potential additional yield per year of 100 million litres from the public water supply reserves. This is a long-term option, not likely to be required before 2040.
Benefits include only small volumes of local groundwater being required to meet population growth, a local water source ensuring minimal pumping, pipes and less energy usage and the water already being set aside in the public water reserves.
Potential issues are that the public water supply reserve may be used first by the Greater Bunbury area, and that groundwater allocation may be reduced.
In the Capel–Donnybrook–Peppermint Grove Beach groundwater area, the Water Corporation is currently licensed to take 450 million litres from Capel–Yarragadee bores, 450 million litres from Donnybrook–Leederville bores, and 150 million litres from Peppermint Grove Beach–Yarragadee bores.
This provides drinking water for an estimated population of 5,000.
The report suggests constructing two Yarragadee bores, one west of Donnybrook and the other east of Capel, with a pipeline connection to Peppermint Grove Beach.
In addition to the bores, it involves constructing water treatment plants, six kilometres of pipeline from Capel and 3.5km of pipeline from Donnybrook.
An alternative option is to develop an integrated scheme connecting all three towns.
This option creates a potential additional yield per year of 1.1 billion litres from public water reserves, and is a medium-term option that may be required before annual demand reaches 400 million litres, which is estimated to be around 2020.
The benefits of the option are that only small volumes of local groundwater are required to meet population growth, the local water source ensures minimal pumping, pipes and less energy usage and the water is already set aside in the public water reserves.
Issues with the plan are that the Capel and Donnybrook townsites may grow faster than expected, making it necessary to develop this source sooner, and that groundwater allocation may be reduced.