The City of Tea Tree Gully north of Adelaide will save over 50,000 kilolitres of mains water each year by treating stormwater to use for the irrigation of Council reserves. Council’s Aquifer Storage and Recovery (ASR) schemes collect stormwater during winter for treatment and harvesting during summer. This involves injecting treated stormwater into underground rock aquifers, which can be pumped out for irrigation purposes.
Council launched its first ASR scheme last year at Solandra Reserve, where between 12 and 15,000 kilolitres of stormwater will be collected each year. Work is almost complete on the Kingfisher Wetlands ASR, which will collect about 40,000 kilolitres. The ASR projects are jointly funded by the South Australian Government’s Catchment Management Subsidy Scheme, the Northern Adelaide and Barossa Catchment Water Management Board, Planning SA and the City of Tea Tree Gully.
“ASR is a bit like depositing money in the bank,” said Brenton Curtis, Manager Environmental Assets. “You try to inject a bit extra during a good year in case the next year is a dry one, so you have a reserve in the aquifer.”
The stormwater is filtered through reeds in the wetlands to remove large particles of rubbish, natural sediment and nutrients. It is then pumped from the wetlands and mechanically treated with a filter and ultra violet light to remove bacteria. It is monitored for suspended solids, pH, temperature and hydrocarbons before being injected into the fractured rock aquifer at a rate of 60 litres per minute.
The injection process shuts down if monitored levels exceed EPA standards. From the aquifer, the treated stormwater is then pumped from the aquifer into an underground holding tank for use in park irrigation. The new Kingfisher Wetland comprises three ponds with a total catchment area of 72 hectares. Planted with 5000 trees and shrubs, it is a picturesque wildlife corridor that is set to become a popular destination for residents and tourists.
For further information contact Brendan Curtis on (08) 8397 7444 or email curtb@cttg.sa.gov.au
