PLANS are under way for the single biggest public works project to be undertaken by Shoalhaven City Council, a $100 million upgrade to the Nowra and Bomaderry sewage treatment plants.
Council engineers have prepared concept designs and undertaken initial consultation with key stakeholders which will see treated effluent redirected from the two plants to the REMS Scheme (the Northern Shoalhaven Reclaimed Water Management Scheme), to be used to irrigate dairy farms on the Shoalhaven River flood plain.
Shoalhaven Water asset planning and development manager Robert Horner said instead of being discharged into the Shoalhaven River, as it is now, the treated effluent would be redirected to local farms.
“Bringing the Nowra and Bomaderry works onto line will double the amount of water available to farmers for irrigation,” he said.
“We will be adding a further seven megalitres [7 million litres] of treated water, or five Olympic swimming pools a day, to the current system.
“At the moment, on average, the system runs at seven megalitres a day and that will increase to 14 megalitres.”
Mr Horner said plans were only at the concept stage and environmental studies, including a review of environmental factors, were being undertaken.
“Geotechnical studies are also being carried out to allow for final structural designs,” he said.
“The Bomaderry plant is located off Railway Street, with the plan to directionally drill under the river, virtually under Pig Island, which will bring it in line with the Nowra treatment plant off Terara Road.
“It is a huge job. If the studies find that the ground is not suitable for the drilling we may need to consider the Bomaderry water coming across the Shoalhaven bridge.
“That has the potential to defer the possible transfer to Nowra – we may decide to wait until the new bridge is built.
“We are also studying if the soft ground on the floodplain can handle the substantial structural building that will take place and if it might need special footings or foundations.”
As part of the work, both treatment plants will also undergo major upgrades, receiving the latest infrastructure, similar to the Culburra and Vincentia sites.
He said any treated water not used by farmers during periods of wet weather would be stored at council’s 600-megalitre storage facility at Coonemia.
Following concept designs, the detailed designed phase is expected take around 12 months, followed by a two-year construction period.
The work should be completed in June 2017.
Extra water can be vital
Numbaa dairy farmer Stewart Menzies welcomes the news of extra water allocation for the REMS Scheme.
“It will certainly help getting extra water to irrigate, especially when things are dry and we desperately need it,” he said.
“It’s a positive move by council.”
Mr Menzies milks around 570 cows on the 470-acre Mountain View farm on Jindy Andy Lane, of which 150 acres are under irrigation with two pivot machines.
“When things are dry, having more water would be great,” he said.
“It is often vital for us.
“It reduces the amount of extra fodder we have to bring onto the property because we can grow it under the irrigation.”
Since the REMS Scheme was launched in 2002, 20 gigalitres of water or 20,000 million litres has been irrigated on local farm lands.
That equates to 15,000 Olympic swimming pools.