HydroPlan was engaged to design a $3 million Margaret River water recycling project for the Augusta-Margaret River Shire in WA .
Prior to this scheme being implemented, all the treated water was used to water tree plantations using drip. But now that Stage 1 has been completed, some of the water which is treated to class “C” will be utilised within the town itself. The treated wastewater will replace river water in order to irrigate the town's parks, gardens, schools and a golf course which is being undertaken as stage 2 of the works. The project has created a long-term sustainable water source for the town's public open spaces. It also provides a more reliable supply of water to improve the quality of the sporting fields and parks and gardens..
Stage 1 of the scheme incorporated 5,700 m of MDPE and PVC piping, and Stage 2 added a further 6,000 m. There are balancing storage tanks at each irrigated site which will be automatically topped up at night by pumping from the Waste Water Treatment Plant. In most cases, the new supply will replace the supply from the Margaret River to these tanks. Each irrigated site has a pump station to pump water from the tanks to an existing irrigation system. Gloucester Park which is the towns premier sporting complex is undergoing an upgrade and part of these works has been the inclusion of a new irrigation booster pumping station as well as new and improved infield sprinkler layouts.
The pipeline was designed using network modelling software to ascertain pressure variations under various combinations of demand and pumping scenarios up to the design flow of 60 L/s. The scheme includes pigging stations for the periodic flushing/cleaning of the lines.
As the system makes use of recycled water there are several forms of protection built into the scheme to allow for any potential failure. The system is designed to operate without any telemetry controls, but provision has been made to incorporate this in the future if so required.
Material and construction specifications referred to appropriate Australian Standards and to the Dual Water Supply Systems issued by the Water Services Association. Signficant challenges included environment and heritage protection and a river crossing.