Willunga Basin Water (WBW) operates a large reclaimed water scheme in South Australia that is privately funded, owned and operated by its water users. It is a magnificent example of what can be achieved when people with a common need come together to tackle water resource challenges in an inspirational manner.
Its origins were back in the mid 1990’s when the first water users formed a joint venture and a company, then the Willunga Basin Water Company, to build Stage I of the pipeline to allow them to pursue their core business of irrigated horticulture (mostly viticulture).
The primary water source was and still is the Christies Beach Wastewater Treatment Plant, located about 10 km north of the Willunga Basin. Its annual treated volume is around 10,000 ML, of which around 55% is used by WBW. Following in-principle support and an approach to the State Government to make use of the wastewater going out to sea at Christies Beach, engineering concepts and a budget were developed. Sufficient landholders and water users put their financial support behind the proposal and the entity was formed that would build the pipeline. State Government gave the scheme State Infrastructure Status to facilitate the schemes implementation.
Although the pipeline’s construction was wholly funded by the water users, they allocated just 25% of its water capacity to themselves. This provided third-party access and allowed for expansion to other areas in the Basin without duplicating the pipeline.
The scheme, which began operating in 1999, now has 7 pump stations, 3 buffering storages, over 120 km of pipeline and manages a further 3 major above ground storages. From an initial contracted demand of 2.1 GL, it has expanded to over 5.45 GL to provide numerous others in the region with access to reclaimed water and has an identified demand for more than another 2 GL. In 2005 construction of a local wastewater plant to treat wastewater from the neighbouring towns of McLaren Flat, McLaren Vale and Willunga has resulted in that treated water being utilised by the WBW scheme.
More recently, WBW now has access to the newly constructed Aldinga bulk storage situated next to the Aldinga Wastewater treatment plant for reuse of water in its distribution system.
Water is given greatest value when it is delivered with minimum fuss and maximum reliability. Growers who use the WBW scheme can irrigate by just turning on their tap – there is no need for storage, power or pumps on farms. Under the water supply agreement, individual users take responsibility for the interaction of their on-farm irrigation system and their property. All users operate a drip irrigation system. There is no need for ‘water ordering’ on the WBW system, with users simply accessing the water supply as required. Each outlet has a flowmeter and a GPRS data logger. Water usage is logged continuously and the data will be accessible via the company website in the near future.
WBW has led the way in the use of reclaimed water technology and now serves as a role model for other demand driven, reclaimed water schemes in Australia. It delivers high environmental value to the community by reducing the discharge of treated effluent to the Gulf St Vincent and replaces water that would otherwise be taken from a stressed groundwater resource and the River Murray. It underpins the economic sustainability of this premium wine region and results in over $38M p.a. of grape value, more than $100M p.a. in base wine value and an inestimable contribution to the tourism industry.
WBW is proud to be part of the mains water substation roll out that has been developed in order to save the River Murray.
Today, with more than 140 users, the scheme has proved most reliable in providing affordable recycled water to irrigate more than 2,000 hectares of some of the best soils in the world for grape growing and other fruits.