Arris was approached by a winery in Victoria to offer consultation on the impact (if any) of using recycled water on their wine grape production and quality. The winery in question has received many awards and has wines that have achieved status on many prestigious and highly sought after lists.
Arris conducted a desktop review of the available data on the soils and recycled water quality in the region to assess the suitability of the vineyard soils for irrigation with recycled water. The use of recycled water for irrigation of wine grapes is widely practiced in Australia. For further information see “Irrigating with Reclaimed Water”. For example, McLaren Vale, one of Australia’s most prominent wine grape regions, receives some of the highest prices for wine grapes in Australia, and is irrigated extensively with Class B/C recycled water.
The water produced at the treatment plant is Class B – a classification that refers to its microbiological content, not its chemical suitability for irrigation. The most significant barrier to the use of recycled water is often the salinity and sodicity of the water, with grapes typically considered moderately sensitive to salinity. The water supplied by the Sunbury recycled water scheme has a Class 2 salinity rating (Vic EPA, 464.2) and had a low sodium absorption ratio of 2.9. After review of soils, irrigation rate, climatic conditions and consultation with other vineyards in the region, it was concluded this water posed a low risk to the soil and grape quality.
“Irrigation with recycled water would be sustainable and in line with good agricultural practice.”
A desktop review of the site showed the soils in the region have good hydraulic conductivity to facilitate drainage of salts and nutrients. The available soil data flagged the fact that subsoil could have a high sodicity which could in fact benefit from the increased salinity of recycled water to improve its drainage.
The outcomes of desktop soil and water review supported the conclusion that irrigation at the target site with recycled water would be sustainable with use in line with ‘good agricultural practice’, resulting in no negative impact on either soil or grape quality.